Game.Timestep is now public

- `SoundInstance.Play` no longer takes a loop parameter
- `SoundInstance.Stop` is split into `Stop` and `StopImmediate` instead of taking an immediate parameter
- Added `StreamingSoundSeekable` to better support streaming audio that does not support seek
- `StreamingSound` no longer has a Loop property, but `StreamingSoundSeekable` does
- abstract `StreamingSound.AddBuffer` renamed to `FillBuffer`
- `FillBuffer` is now provided with a native buffer to avoid an extra data copy
- `StreamingSound` buffer implementation optimized to avoid repeated alloc/frees

- added `Video` class which can load and play Theora (.ogv) streaming video/audio

Reviewed-on: MoonsideGames/MoonWorks#20

.gitmodules

@@ -7,3 +7,9 @@
 [submodule "lib/RefreshCS"]
 	path = lib/RefreshCS
 	url = https://gitea.moonside.games/MoonsideGames/RefreshCS.git
+[submodule "lib/WellspringCS"]
+	path = lib/WellspringCS
+	url = https://gitea.moonside.games/MoonsideGames/WellspringCS.git
+[submodule "lib/Theorafile"]
+	path = lib/Theorafile
+	url = https://github.com/FNA-XNA/Theorafile.git

MoonWorks.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFramework>net5.0</TargetFramework>
+		<TargetFramework>net6.0</TargetFramework>
 		<Platforms>x64</Platforms>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
 	</PropertyGroup>
@@ -14,6 +14,8 @@
 		<ProjectReference Include=".\lib\SDL2-CS\SDL2-CS.Core.csproj" />
 		<ProjectReference Include=".\lib\RefreshCS\RefreshCS.csproj" />
 		<ProjectReference Include=".\lib\FAudio\csharp\FAudio-CS.Core.csproj" />
+		<ProjectReference Include=".\lib\WellspringCS\WellspringCS.csproj" />
+		<ProjectReference Include=".\lib\Theorafile\csharp\Theorafile-CS.Core.csproj" />
 	</ItemGroup>
 
 	<ItemGroup>
@@ -21,4 +23,13 @@
 			<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
 		</None>
 	</ItemGroup>
+
+	<ItemGroup>
+		<EmbeddedResource Include="src\Video\Shaders\Compiled\FullscreenVert.spv">
+			<LogicalName>MoonWorks.Shaders.FullscreenVert.spv</LogicalName>
+		</EmbeddedResource>
+		<EmbeddedResource Include="src\Video\Shaders\Compiled\YUV2RGBAFrag.spv">
+			<LogicalName>MoonWorks.Shaders.YUV2RGBAFrag.spv</LogicalName>
+		</EmbeddedResource>
+	</ItemGroup>
 </Project>

MoonWorks.dll.config

@@ -11,4 +11,12 @@
 	<dllmap dll="FAudio" os="windows" target="FAudio.dll"/>
 	<dllmap dll="FAudio" os="osx" target="libFAudio.0.dylib"/>
 	<dllmap dll="FAudio" os="linux,freebsd,netbsd" target="libFAudio.so.0"/>
+
+	<dllmap dll="Wellspring" os="windows" target="Wellspring.dll"/>
+	<dllmap dll="Wellspring" os="osx" target="libWellspring.0.dylib"/>
+	<dllmap dll="Wellspring" os="linux,freebsd,netbsd" target="libWellspring.so.0"/>
+
+	<dllmap dll="Theorafile" os="windows" target="libtheorafile.dll"/>
+	<dllmap dll="Theorafile" os="osx" target="libtheorafile.dylib"/>
+	<dllmap dll="Theorafile" os="linux,freebsd,netbsd" target="libtheorafile.so"/>
 </configuration>

MoonWorks.sln

@@ -14,6 +14,10 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "FAudio-CS.Core", "lib\FAudi
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "RefreshCS", "lib\RefreshCS\RefreshCS.csproj", "{AD7C94E4-0AFA-44CA-889C-110142369893}"
 EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "lib", "lib", "{69D3788D-6C57-44F7-A912-B201AE6D7C04}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "WellspringCS", "lib\WellspringCS\WellspringCS.csproj", "{0DD7B866-773C-4A86-8580-F436DAA28989}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|x64 = Debug|x64
@@ -36,6 +40,10 @@ Global
 		{AD7C94E4-0AFA-44CA-889C-110142369893}.Debug|x64.Build.0 = Debug|x64
 		{AD7C94E4-0AFA-44CA-889C-110142369893}.Release|x64.ActiveCfg = Release|x64
 		{AD7C94E4-0AFA-44CA-889C-110142369893}.Release|x64.Build.0 = Release|x64
+		{0DD7B866-773C-4A86-8580-F436DAA28989}.Debug|x64.ActiveCfg = Debug|x64
+		{0DD7B866-773C-4A86-8580-F436DAA28989}.Debug|x64.Build.0 = Debug|x64
+		{0DD7B866-773C-4A86-8580-F436DAA28989}.Release|x64.ActiveCfg = Release|x64
+		{0DD7B866-773C-4A86-8580-F436DAA28989}.Release|x64.Build.0 = Release|x64
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -43,4 +51,7 @@ Global
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {C3D68FAA-3165-43C7-95B3-D845F0DAA918}
 	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{0DD7B866-773C-4A86-8580-F436DAA28989} = {69D3788D-6C57-44F7-A912-B201AE6D7C04}
+	EndGlobalSection
 EndGlobal

README.md

@@ -10,11 +10,21 @@ MoonWorks *does not* include things like a built-in physics engine, a GUI editor
 
 MoonWorks uses strictly Free Open Source Software. It will never have any kind of dependency on proprietary products.
 
+## Documentation
+
+High-level documentation is provided here: http://moonside.games/docs/moonworks/
+
+For an actual API reference, the source is documented in doc comments that your preferred IDE can read.
+
 ## Dependencies
 
 * [SDL2](https://github.com/flibitijibibo/SDL2-CS) - Window management, Input
 * [Refresh](https://gitea.moonside.games/MoonsideGames/Refresh) - Graphics
 * [FAudio](https://github.com/FNA-XNA/FAudio) - Audio
+* [Wellspring](https://gitea.moonside.games/MoonsideGames/Wellspring) - Font Rendering
+* [Theorafile](https://github.com/FNA-XNA/Theorafile) - Compressed Video
+
+Prebuilt dependencies can be obtained here: http://moonside.games/files/moonlibs.tar.bz2
 
 ## License
 

lib/FAudio

@@ -1 +1 @@
-Subproject commit de0c1f833c12a992af5c7daebe1705cd2c72f743
+Subproject commit 0b6d5dabbf428633482fe3a956fbdb53228fcf35

lib/RefreshCS

@@ -1 +1 @@
-Subproject commit 5a411e482ebe619a7e85c44584faa5bd71b7ee3b
+Subproject commit 98c590ae77c3b6a64a370bac439f20728959a8b6

lib/SDL2-CS

@@ -1 +1 @@
-Subproject commit 4e9088b49de46ea8b4285948cfe69875ac4c2290
+Subproject commit b35aaa494e44d08242788ff0ba2cb7a508f4d8f0

lib/Theorafile

@@ -0,0 +1 @@
+Subproject commit dd8c7fa69e678b6182cdaa71458ad08dd31c65da

lib/WellspringCS

@@ -0,0 +1 @@
+Subproject commit f8872bae59e394b0f8a35224bb39ab8fd041af97

src/Audio/AudioDevice.cs

@@ -107,13 +107,13 @@ namespace MoonWorks.Audio
 
 			IntPtr chainPtr;
 			chainPtr = Marshal.AllocHGlobal(
-				Marshal.SizeOf<FAudio.FAudioEffectChain>()
+				sizeof(FAudio.FAudioEffectChain)
 			);
 
 			FAudio.FAudioEffectChain* reverbChain = (FAudio.FAudioEffectChain*) chainPtr;
 			reverbChain->EffectCount = 1;
 			reverbChain->pEffectDescriptors = Marshal.AllocHGlobal(
-				Marshal.SizeOf<FAudio.FAudioEffectDescriptor>()
+				sizeof(FAudio.FAudioEffectDescriptor)
 			);
 
 			FAudio.FAudioEffectDescriptor* reverbDescriptor =
@@ -146,7 +146,7 @@ namespace MoonWorks.Audio
 			// Defaults based on FAUDIOFX_I3DL2_PRESET_GENERIC
 
 			IntPtr reverbParamsPtr = Marshal.AllocHGlobal(
-				Marshal.SizeOf<FAudio.FAudioFXReverbParameters>()
+				sizeof(FAudio.FAudioFXReverbParameters)
 			);
 
 			FAudio.FAudioFXReverbParameters* reverbParams = (FAudio.FAudioFXReverbParameters*) reverbParamsPtr;
@@ -176,7 +176,7 @@ namespace MoonWorks.Audio
 				ReverbVoice,
 				0,
 				reverbParamsPtr,
-				(uint) Marshal.SizeOf<FAudio.FAudioFXReverbParameters>(),
+				(uint) sizeof(FAudio.FAudioFXReverbParameters),
 				0
 			);
 			Marshal.FreeHGlobal(reverbParamsPtr);
@@ -187,7 +187,7 @@ namespace MoonWorks.Audio
 			{
 				SendCount = 2,
 				pSends = Marshal.AllocHGlobal(
-					2 * Marshal.SizeOf<FAudio.FAudioSendDescriptor>()
+					2 * sizeof(FAudio.FAudioSendDescriptor)
 				)
 			};
 			FAudio.FAudioSendDescriptor* sendDesc = (FAudio.FAudioSendDescriptor*) ReverbSends.pSends;
@@ -197,7 +197,12 @@ namespace MoonWorks.Audio
 			sendDesc[1].pOutputVoice = ReverbVoice;
 		}
 
-		public void Update()
+		public void SetMasteringVolume(float volume)
+		{
+			FAudio.FAudioVoice_SetVolume(MasteringVoice, volume, 0);
+		}
+
+		internal void Update()
 		{
 			for (var i = streamingSounds.Count - 1; i >= 0; i--)
 			{
@@ -240,16 +245,16 @@ namespace MoonWorks.Audio
 			{
 				if (disposing)
 				{
-					for (var i = streamingSounds.Count - 1; i >= 0; i--)
+					for (var i = resources.Count - 1; i >= 0; i--)
 					{
-						var weakReference = streamingSounds[i];
+						var weakReference = resources[i];
 
-						if (weakReference.TryGetTarget(out var streamingSound))
+						if (weakReference.TryGetTarget(out var resource))
 						{
-							streamingSound.Dispose();
+							resource.Dispose();
 						}
 					}
-					streamingSounds.Clear();
+					resources.Clear();
 				}
 
 				FAudio.FAudioVoice_DestroyVoice(ReverbVoice);

src/Audio/AudioEmitter.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
-using MoonWorks.Math;
+using MoonWorks.Math.Float;
 
 namespace MoonWorks.Audio
 {

src/Audio/AudioListener.cs

@@ -1,5 +1,5 @@
 using System;
-using MoonWorks.Math;
+using MoonWorks.Math.Float;
 
 namespace MoonWorks.Audio
 {

src/Audio/SoundInstance.cs

@@ -1,20 +1,18 @@
 using System;
 using System.Runtime.InteropServices;
-using MoonWorks.Math;
 
 namespace MoonWorks.Audio
 {
 	public abstract class SoundInstance : AudioResource
 	{
-		internal IntPtr Handle { get; }
+		internal IntPtr Handle;
-		internal FAudio.FAudioWaveFormatEx Format { get; }
+		internal FAudio.FAudioWaveFormatEx Format;
-		public bool Loop { get; }
 
 		protected FAudio.F3DAUDIO_DSP_SETTINGS dspSettings;
 
-		protected bool is3D;
+		public bool Is3D { get; protected set; }
 
-		public abstract SoundState State { get; protected set; }
+		public virtual SoundState State { get; protected set; }
 
 		private float _pan = 0;
 		public float Pan
@@ -33,7 +31,7 @@ namespace MoonWorks.Audio
 					_pan = 1f;
 				}
 
-				if (is3D) { return; }
+				if (Is3D) { return; }
 
 				SetPanMatrixCoefficients();
 				FAudio.FAudioVoice_SetOutputMatrix(
@@ -53,7 +51,7 @@ namespace MoonWorks.Audio
 			get => _pitch;
 			set
 			{
-				_pitch = MathHelper.Clamp(value, -1f, 1f);
+				_pitch = Math.MathHelper.Clamp(value, -1f, 1f);
 				UpdatePitch();
 			}
 		}
@@ -163,17 +161,17 @@ namespace MoonWorks.Audio
 
 		public SoundInstance(
 			AudioDevice device,
+			ushort formatTag,
+			ushort bitsPerSample,
+			ushort blockAlign,
 			ushort channels,
-			uint samplesPerSecond,
+			uint samplesPerSecond
-			bool is3D,
-			bool loop
 		) : base(device)
 		{
-			var blockAlign = (ushort) (4 * channels);
 			var format = new FAudio.FAudioWaveFormatEx
 			{
-				wFormatTag = 3,
+				wFormatTag = formatTag,
-				wBitsPerSample = 32,
+				wBitsPerSample = bitsPerSample,
 				nChannels = channels,
 				nBlockAlign = blockAlign,
 				nSamplesPerSec = samplesPerSecond,
@@ -184,8 +182,8 @@ namespace MoonWorks.Audio
 
 			FAudio.FAudio_CreateSourceVoice(
 				Device.Handle,
-				out var handle,
+				out Handle,
-				ref format,
+				ref Format,
 				FAudio.FAUDIO_VOICE_USEFILTER,
 				FAudio.FAUDIO_DEFAULT_FREQ_RATIO,
 				IntPtr.Zero,
@@ -193,28 +191,28 @@ namespace MoonWorks.Audio
 				IntPtr.Zero
 			);
 
-			if (handle == IntPtr.Zero)
+			if (Handle == IntPtr.Zero)
 			{
 				Logger.LogError("SoundInstance failed to initialize!");
 				return;
 			}
 
-			Handle = handle;
-			this.is3D = is3D;
 			InitDSPSettings(Format.nChannels);
 
+			// FIXME: not everything should be running through reverb...
+			/*
 			FAudio.FAudioVoice_SetOutputVoices(
-				handle,
+				Handle,
 				ref Device.ReverbSends
 			);
+			*/
 
-			Loop = loop;
 			State = SoundState.Stopped;
 		}
 
 		public void Apply3D(AudioListener listener, AudioEmitter emitter)
 		{
-			is3D = true;
+			Is3D = true;
 
 			emitter.emitterData.CurveDistanceScaler = Device.CurveDistanceScalar;
 			emitter.emitterData.ChannelCount = dspSettings.SrcChannelCount;
@@ -240,7 +238,8 @@ namespace MoonWorks.Audio
 
 		public abstract void Play();
 		public abstract void Pause();
-		public abstract void Stop(bool immediate);
+		public abstract void Stop();
+		public abstract void StopImmediate();
 
 		private void InitDSPSettings(uint srcChannels)
 		{
@@ -271,7 +270,7 @@ namespace MoonWorks.Audio
 		{
 			float doppler;
 			float dopplerScale = Device.DopplerScale;
-			if (!is3D || dopplerScale == 0.0f)
+			if (!Is3D || dopplerScale == 0.0f)
 			{
 				doppler = 1.0f;
 			}
@@ -343,8 +342,7 @@ namespace MoonWorks.Audio
 
 		protected override void Destroy()
 		{
-			Stop(true);
+			StopImmediate();
-
 			FAudio.FAudioVoice_DestroyVoice(Handle);
 			Marshal.FreeHGlobal(dspSettings.pMatrixCoefficients);
 		}

src/Audio/StaticSound.cs

@@ -1,4 +1,6 @@
-using System;
+using System;
+using System.Collections.Generic;
+using System.IO;
 using System.Runtime.InteropServices;
 
 namespace MoonWorks.Audio
@@ -6,12 +8,17 @@ namespace MoonWorks.Audio
 	public class StaticSound : AudioResource
 	{
 		internal FAudio.FAudioBuffer Handle;
+		public ushort FormatTag { get; }
+		public ushort BitsPerSample { get; }
 		public ushort Channels { get; }
 		public uint SamplesPerSecond { get; }
+		public ushort BlockAlign { get; }
 
 		public uint LoopStart { get; set; } = 0;
 		public uint LoopLength { get; set; } = 0;
 
+		private Stack<StaticSoundInstance> Instances = new Stack<StaticSoundInstance>();
+
 		public static StaticSound LoadOgg(AudioDevice device, string filePath)
 		{
 			var filePointer = FAudio.stb_vorbis_open_filename(filePath, out var error, IntPtr.Zero);
@@ -43,6 +50,194 @@ namespace MoonWorks.Audio
 			);
 		}
 
+		// mostly borrowed from https://github.com/FNA-XNA/FNA/blob/b71b4a35ae59970ff0070dea6f8620856d8d4fec/src/Audio/SoundEffect.cs#L385
+		public static StaticSound LoadWav(AudioDevice device, string filePath)
+		{
+			// Sample data
+			byte[] data;
+
+			// WaveFormatEx data
+			ushort wFormatTag;
+			ushort nChannels;
+			uint nSamplesPerSec;
+			uint nAvgBytesPerSec;
+			ushort nBlockAlign;
+			ushort wBitsPerSample;
+			int samplerLoopStart = 0;
+			int samplerLoopEnd = 0;
+
+			using (BinaryReader reader = new BinaryReader(File.OpenRead(filePath)))
+			{
+				// RIFF Signature
+				string signature = new string(reader.ReadChars(4));
+				if (signature != "RIFF")
+				{
+					throw new NotSupportedException("Specified stream is not a wave file.");
+				}
+
+				reader.ReadUInt32(); // Riff Chunk Size
+
+				string wformat = new string(reader.ReadChars(4));
+				if (wformat != "WAVE")
+				{
+					throw new NotSupportedException("Specified stream is not a wave file.");
+				}
+
+				// WAVE Header
+				string format_signature = new string(reader.ReadChars(4));
+				while (format_signature != "fmt ")
+				{
+					reader.ReadBytes(reader.ReadInt32());
+					format_signature = new string(reader.ReadChars(4));
+				}
+
+				int format_chunk_size = reader.ReadInt32();
+
+				wFormatTag = reader.ReadUInt16();
+				nChannels = reader.ReadUInt16();
+				nSamplesPerSec = reader.ReadUInt32();
+				nAvgBytesPerSec = reader.ReadUInt32();
+				nBlockAlign = reader.ReadUInt16();
+				wBitsPerSample = reader.ReadUInt16();
+
+				// Reads residual bytes
+				if (format_chunk_size > 16)
+				{
+					reader.ReadBytes(format_chunk_size - 16);
+				}
+
+				// data Signature
+				string data_signature = new string(reader.ReadChars(4));
+				while (data_signature.ToLowerInvariant() != "data")
+				{
+					reader.ReadBytes(reader.ReadInt32());
+					data_signature = new string(reader.ReadChars(4));
+				}
+				if (data_signature != "data")
+				{
+					throw new NotSupportedException("Specified wave file is not supported.");
+				}
+
+				int waveDataLength = reader.ReadInt32();
+				data = reader.ReadBytes(waveDataLength);
+
+				// Scan for other chunks
+				while (reader.PeekChar() != -1)
+				{
+					char[] chunkIDChars = reader.ReadChars(4);
+					if (chunkIDChars.Length < 4)
+					{
+						break; // EOL!
+					}
+					byte[] chunkSizeBytes = reader.ReadBytes(4);
+					if (chunkSizeBytes.Length < 4)
+					{
+						break; // EOL!
+					}
+					string chunk_signature = new string(chunkIDChars);
+					int chunkDataSize = BitConverter.ToInt32(chunkSizeBytes, 0);
+					if (chunk_signature == "smpl") // "smpl", Sampler Chunk Found
+					{
+						reader.ReadUInt32(); // Manufacturer
+						reader.ReadUInt32(); // Product
+						reader.ReadUInt32(); // Sample Period
+						reader.ReadUInt32(); // MIDI Unity Note
+						reader.ReadUInt32(); // MIDI Pitch Fraction
+						reader.ReadUInt32(); // SMPTE Format
+						reader.ReadUInt32(); // SMPTE Offset
+						uint numSampleLoops = reader.ReadUInt32();
+						int samplerData = reader.ReadInt32();
+
+						for (int i = 0; i < numSampleLoops; i += 1)
+						{
+							reader.ReadUInt32(); // Cue Point ID
+							reader.ReadUInt32(); // Type
+							int start = reader.ReadInt32();
+							int end = reader.ReadInt32();
+							reader.ReadUInt32(); // Fraction
+							reader.ReadUInt32(); // Play Count
+
+							if (i == 0) // Grab loopStart and loopEnd from first sample loop
+							{
+								samplerLoopStart = start;
+								samplerLoopEnd = end;
+							}
+						}
+
+						if (samplerData != 0) // Read Sampler Data if it exists
+						{
+							reader.ReadBytes(samplerData);
+						}
+					}
+					else // Read unwanted chunk data and try again
+					{
+						reader.ReadBytes(chunkDataSize);
+					}
+				}
+				// End scan
+			}
+
+			return new StaticSound(
+				device,
+				wFormatTag,
+				wBitsPerSample,
+				nBlockAlign,
+				nChannels,
+				nSamplesPerSec,
+				data,
+				0,
+				(uint) data.Length
+			);
+		}
+
+		public StaticSound(
+			AudioDevice device,
+			ushort formatTag,
+			ushort bitsPerSample,
+			ushort blockAlign,
+			ushort channels,
+			uint samplesPerSecond,
+			byte[] buffer,
+			uint bufferOffset, /* number of bytes */
+			uint bufferLength /* number of bytes */
+		) : base(device)
+		{
+			FormatTag = formatTag;
+			BitsPerSample = bitsPerSample;
+			BlockAlign = blockAlign;
+			Channels = channels;
+			SamplesPerSecond = samplesPerSecond;
+
+			Handle = new FAudio.FAudioBuffer();
+			Handle.Flags = FAudio.FAUDIO_END_OF_STREAM;
+			Handle.pContext = IntPtr.Zero;
+			Handle.AudioBytes = bufferLength;
+			Handle.pAudioData = Marshal.AllocHGlobal((int) bufferLength);
+			Marshal.Copy(buffer, (int) bufferOffset, Handle.pAudioData, (int) bufferLength);
+			Handle.PlayBegin = 0;
+			Handle.PlayLength = 0;
+
+			if (formatTag == 1)
+			{
+				Handle.PlayLength = (uint) (
+					bufferLength /
+					channels /
+					(bitsPerSample / 8)
+				);
+			}
+			else if (formatTag == 2)
+			{
+				Handle.PlayLength = (uint) (
+					bufferLength /
+					blockAlign *
+					(((blockAlign / channels) - 6) * 2)
+				);
+			}
+
+			LoopStart = 0;
+			LoopLength = 0;
+		}
+
 		public StaticSound(
 			AudioDevice device,
 			ushort channels,
@@ -52,6 +247,9 @@ namespace MoonWorks.Audio
 			uint bufferLength  /* in floats */
 		) : base(device)
 		{
+			FormatTag = 3;
+			BitsPerSample = 32;
+			BlockAlign = (ushort) (4 * channels);
 			Channels = channels;
 			SamplesPerSecond = samplesPerSecond;
 
@@ -69,9 +267,23 @@ namespace MoonWorks.Audio
 			LoopLength = 0;
 		}
 
-		public StaticSoundInstance CreateInstance(bool loop = false)
+		/// <summary>
+		/// Gets a sound instance from the pool.
+		/// NOTE: If you lose track of instances, you will create garbage collection pressure!
+		/// </summary>
+		public StaticSoundInstance GetInstance()
 		{
-			return new StaticSoundInstance(Device, this, false, loop);
+			if (Instances.Count == 0)
+			{
+				Instances.Push(new StaticSoundInstance(Device, this));
+			}
+
+			return Instances.Pop();
+		}
+
+		internal void FreeInstance(StaticSoundInstance instance)
+		{
+			Instances.Push(instance);
 		}
 
 		protected override void Destroy()

src/Audio/StaticSoundInstance.cs

@@ -6,6 +6,8 @@ namespace MoonWorks.Audio
 	{
 		public StaticSound Parent { get; }
 
+		public bool Loop { get; set; }
+
 		private SoundState _state = SoundState.Stopped;
 		public override SoundState State
 		{
@@ -18,7 +20,7 @@ namespace MoonWorks.Audio
 				);
 				if (state.BuffersQueued == 0)
 				{
-					Stop(true);
+					StopImmediate();
 				}
 
 				return _state;
@@ -32,10 +34,8 @@ namespace MoonWorks.Audio
 
 		internal StaticSoundInstance(
 			AudioDevice device,
-			StaticSound parent,
+			StaticSound parent
-			bool is3D,
+		) : base(device, parent.FormatTag, parent.BitsPerSample, parent.BlockAlign, parent.Channels, parent.SamplesPerSecond)
-			bool loop
-		) : base(device, parent.Channels, parent.SamplesPerSecond, is3D, loop)
 		{
 			Parent = parent;
 		}
@@ -79,18 +79,33 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		public override void Stop(bool immediate = true)
+		public override void Stop()
 		{
-			if (immediate)
+			FAudio.FAudioSourceVoice_ExitLoop(Handle, 0);
+			State = SoundState.Stopped;
+		}
+
+		public override void StopImmediate()
+		{
+			FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
+			FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
+			State = SoundState.Stopped;
+		}
+
+		public void Seek(uint sampleFrame)
+		{
+			if (State == SoundState.Playing)
 			{
 				FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
 				FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
-				State = SoundState.Stopped;
-			}
-			else
-			{
-				FAudio.FAudioSourceVoice_ExitLoop(Handle, 0);
 			}
+
+			Parent.Handle.PlayBegin = sampleFrame;
+		}
+
+		public void Free()
+		{
+			Parent.FreeInstance(this);
 		}
 	}
 }

src/Audio/StreamingSound.cs

@@ -1,28 +1,38 @@
 using System;
-using System.Collections.Generic;
 using System.Runtime.InteropServices;
 
 namespace MoonWorks.Audio
 {
 	/// <summary>
 	/// For streaming long playback.
-	/// Can be extended to support custom decoders.
+	/// Must be extended with a decoder routine called by FillBuffer.
+	/// See StreamingSoundOgg for an example.
 	/// </summary>
 	public abstract class StreamingSound : SoundInstance
 	{
-		private readonly List<IntPtr> queuedBuffers = new List<IntPtr>();
+		private const int BUFFER_COUNT = 3;
-		private readonly List<uint> queuedSizes = new List<uint>();
+		private readonly IntPtr[] buffers;
-		private const int MINIMUM_BUFFER_CHECK = 3;
+		private int nextBufferIndex = 0;
+		private uint queuedBufferCount = 0;
+		protected abstract int BUFFER_SIZE { get; }
 
-		public int PendingBufferCount => queuedBuffers.Count;
+		public unsafe StreamingSound(
-
-		public StreamingSound(
 			AudioDevice device,
+			ushort formatTag,
+			ushort bitsPerSample,
+			ushort blockAlign,
 			ushort channels,
-			uint samplesPerSecond,
+			uint samplesPerSecond
-			bool is3D,
+		) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond)
-			bool loop
+		{
-		) : base(device, channels, samplesPerSecond, is3D, loop) { }
+			device.AddDynamicSoundInstance(this);
+
+			buffers = new IntPtr[BUFFER_COUNT];
+			for (int i = 0; i < BUFFER_COUNT; i += 1)
+			{
+				buffers[i] = (IntPtr) NativeMemory.Alloc((nuint) BUFFER_SIZE);
+			}
+		}
 
 		public override void Play()
 		{
@@ -32,6 +42,7 @@ namespace MoonWorks.Audio
 			}
 
 			State = SoundState.Playing;
+
 			Update();
 			FAudio.FAudioSourceVoice_Start(Handle, 0, 0);
 		}
@@ -45,19 +56,21 @@ namespace MoonWorks.Audio
 			}
 		}
 
-		public override void Stop(bool immediate = true)
+		public override void Stop()
 		{
-			if (immediate)
+			State = SoundState.Stopped;
-			{
+		}
-				FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
+
-				FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
+		public override void StopImmediate()
-				ClearBuffers();
+		{
-			}
+			FAudio.FAudioSourceVoice_Stop(Handle, 0, 0);
+			FAudio.FAudioSourceVoice_FlushSourceBuffers(Handle);
+			ClearBuffers();
 
 			State = SoundState.Stopped;
 		}
 
-		internal void Update()
+		internal unsafe void Update()
 		{
 			if (State != SoundState.Playing)
 			{
@@ -70,109 +83,83 @@ namespace MoonWorks.Audio
 				FAudio.FAUDIO_VOICE_NOSAMPLESPLAYED
 			);
 
-			while (PendingBufferCount > state.BuffersQueued)
+			queuedBufferCount = state.BuffersQueued;
-				lock (queuedBuffers)
-				{
-					Marshal.FreeHGlobal(queuedBuffers[0]);
-					queuedBuffers.RemoveAt(0);
-				}
 
 			QueueBuffers();
 		}
 
 		protected void QueueBuffers()
 		{
-			for (
+			for (int i = 0; i < BUFFER_COUNT - queuedBufferCount; i += 1)
-				int i = MINIMUM_BUFFER_CHECK - PendingBufferCount;
-				i > 0;
-				i -= 1
-			)
 			{
 				AddBuffer();
 			}
 		}
 
-		protected void ClearBuffers()
+		protected unsafe void ClearBuffers()
 		{
-			lock (queuedBuffers)
+			nextBufferIndex = 0;
-			{
+			queuedBufferCount = 0;
-				foreach (IntPtr buf in queuedBuffers)
-				{
-					Marshal.FreeHGlobal(buf);
-				}
-				queuedBuffers.Clear();
-				queuedSizes.Clear();
-			}
 		}
 
-		protected void AddBuffer()
+		protected unsafe void AddBuffer()
 		{
-			AddBuffer(
+			var buffer = buffers[nextBufferIndex];
-				out var buffer,
+			nextBufferIndex = (nextBufferIndex + 1) % BUFFER_COUNT;
-				out var bufferOffset,
+
-				out var bufferLength,
+			FillBuffer(
-				out var reachedEnd
+				(void*) buffer,
+				BUFFER_SIZE,
+				out int filledLengthInBytes,
+				out bool reachedEnd
 			);
 
-			var lengthInBytes = bufferLength * sizeof(float);
+			FAudio.FAudioBuffer buf = new FAudio.FAudioBuffer
-
-			IntPtr next = Marshal.AllocHGlobal((int) lengthInBytes);
-			Marshal.Copy(buffer, (int) bufferOffset, next, (int) bufferLength);
-
-			lock (queuedBuffers)
 			{
-				queuedBuffers.Add(next);
+				AudioBytes = (uint) filledLengthInBytes,
-				if (State != SoundState.Stopped)
+				pAudioData = (IntPtr) buffer,
-				{
+				PlayLength = (
-					FAudio.FAudioBuffer buf = new FAudio.FAudioBuffer
+					(uint) (filledLengthInBytes /
-					{
+					Format.nChannels /
-						AudioBytes = lengthInBytes,
+					(uint) (Format.wBitsPerSample / 8))
-						pAudioData = next,
+				)
-						PlayLength = (
+			};
-							lengthInBytes /
-							Format.nChannels /
-							(uint) (Format.wBitsPerSample / 8)
-						)
-					};
 
-					FAudio.FAudioSourceVoice_SubmitSourceBuffer(
+			FAudio.FAudioSourceVoice_SubmitSourceBuffer(
-						Handle,
+				Handle,
-						ref buf,
+				ref buf,
-						IntPtr.Zero
+				IntPtr.Zero
-					);
+			);
-				}
+
-				else
+			queuedBufferCount += 1;
-				{
-					queuedSizes.Add(lengthInBytes);
-				}
-			}
 
 			/* We have reached the end of the file, what do we do? */
 			if (reachedEnd)
 			{
-				if (Loop)
+				OnReachedEnd();
-				{
-					SeekStart();
-				}
-				else
-				{
-					Stop(false);
-				}
 			}
 		}
 
-		protected abstract void AddBuffer(
+		protected virtual void OnReachedEnd()
-			out float[] buffer,
+		{
-			out uint bufferOffset, /* in floats */
+			Stop();
-			out uint bufferLength, /* in floats */
+		}
+
+		protected unsafe abstract void FillBuffer(
+			void* buffer,
+			int bufferLengthInBytes, /* in bytes */
+			out int filledLengthInBytes, /* in bytes */
 			out bool reachedEnd
 		);
 
-		protected abstract void SeekStart();
+		protected unsafe override void Destroy()
-
-		protected override void Destroy()
 		{
-			Stop(true);
+			StopImmediate();
+
+			for (int i = 0; i < BUFFER_COUNT; i += 1)
+			{
+				NativeMemory.Free((void*) buffers[i]);
+			}
 		}
 	}
 }

src/Audio/StreamingSoundOgg.cs

@@ -1,91 +1,90 @@
 using System;
 using System.IO;
+using System.Runtime.InteropServices;
 
 namespace MoonWorks.Audio
 {
-	public class StreamingSoundOgg : StreamingSound
+	public class StreamingSoundOgg : StreamingSoundSeekable
 	{
-		// FIXME: what should this value be?
+		private IntPtr VorbisHandle;
-		public const int BUFFER_SIZE = 1024 * 128;
+		private IntPtr FileDataPtr;
+		private FAudio.stb_vorbis_info Info;
 
-		internal IntPtr FileHandle { get; }
+		protected override int BUFFER_SIZE => 32768;
-		internal FAudio.stb_vorbis_info Info { get; }
 
-		private readonly float[] buffer;
+		public unsafe static StreamingSoundOgg Load(AudioDevice device, string filePath)
-
-		public override SoundState State { get; protected set; }
-
-		public static StreamingSoundOgg Load(
-			AudioDevice device,
-			string filePath,
-			bool is3D = false,
-			bool loop = false
-		)
 		{
-			var fileHandle = FAudio.stb_vorbis_open_filename(filePath, out var error, IntPtr.Zero);
+			var fileData = File.ReadAllBytes(filePath);
+			var fileDataPtr = NativeMemory.Alloc((nuint) fileData.Length);
+			Marshal.Copy(fileData, 0, (IntPtr) fileDataPtr, fileData.Length);
+			var vorbisHandle = FAudio.stb_vorbis_open_memory((IntPtr) fileDataPtr, fileData.Length, out int error, IntPtr.Zero);
 			if (error != 0)
 			{
+				NativeMemory.Free(fileDataPtr);
 				Logger.LogError("Error opening OGG file!");
+				Logger.LogError("Error: " + error);
 				throw new AudioLoadException("Error opening OGG file!");
 			}
-
+			var info = FAudio.stb_vorbis_get_info(vorbisHandle);
-			var info = FAudio.stb_vorbis_get_info(fileHandle);
 
 			return new StreamingSoundOgg(
 				device,
-				fileHandle,
+				(IntPtr) fileDataPtr,
-				info,
+				vorbisHandle,
-				is3D,
+				info
-				loop
 			);
 		}
 
 		internal StreamingSoundOgg(
 			AudioDevice device,
-			IntPtr fileHandle,
+			IntPtr fileDataPtr, // MUST BE A NATIVE MEMORY HANDLE!!
-			FAudio.stb_vorbis_info info,
+			IntPtr vorbisHandle,
-			bool is3D,
+			FAudio.stb_vorbis_info info
-			bool loop
+		) : base(
-		) : base(device, (ushort) info.channels, info.sample_rate, is3D, loop)
+			device,
+			3, /* float type */
+			32, /* size of float */
+			(ushort) (4 * info.channels),
+			(ushort) info.channels,
+			info.sample_rate
+		)
 		{
-			FileHandle = fileHandle;
+			FileDataPtr = fileDataPtr;
+			VorbisHandle = vorbisHandle;
 			Info = info;
-			buffer = new float[BUFFER_SIZE];
-
-			device.AddDynamicSoundInstance(this);
 		}
 
-		protected override void AddBuffer(
+		public override void Seek(uint sampleFrame)
-			out float[] buffer,
+		{
-			out uint bufferOffset,
+			FAudio.stb_vorbis_seek(VorbisHandle, sampleFrame);
-			out uint bufferLength,
+		}
+
+		protected unsafe override void FillBuffer(
+			void* buffer,
+			int bufferLengthInBytes,
+			out int filledLengthInBytes,
 			out bool reachedEnd
 		)
 		{
-			buffer = this.buffer;
+			var lengthInFloats = bufferLengthInBytes / sizeof(float);
 
 			/* NOTE: this function returns samples per channel, not total samples */
 			var samples = FAudio.stb_vorbis_get_samples_float_interleaved(
-				FileHandle,
+				VorbisHandle,
 				Info.channels,
-				buffer,
+				(IntPtr) buffer,
-				buffer.Length
+				lengthInFloats
 			);
 
 			var sampleCount = samples * Info.channels;
-			bufferOffset = 0;
+			reachedEnd = sampleCount < lengthInFloats;
-			bufferLength = (uint) sampleCount;
+			filledLengthInBytes = sampleCount * sizeof(float);
-			reachedEnd = sampleCount < buffer.Length;
 		}
 
-		protected override void SeekStart()
+		protected unsafe override void Destroy()
 		{
-			FAudio.stb_vorbis_seek_start(FileHandle);
+			FAudio.stb_vorbis_close(VorbisHandle);
-		}
+			NativeMemory.Free((void*) FileDataPtr);
-
-		protected override void Destroy()
-		{
-			FAudio.stb_vorbis_close(FileHandle);
 		}
 	}
 }

src/Audio/StreamingSoundSeekable.cs

@@ -0,0 +1,25 @@
+namespace MoonWorks.Audio
+{
+	public abstract class StreamingSoundSeekable : StreamingSound
+	{
+		public bool Loop { get; set; }
+
+		protected StreamingSoundSeekable(AudioDevice device, ushort formatTag, ushort bitsPerSample, ushort blockAlign, ushort channels, uint samplesPerSecond) : base(device, formatTag, bitsPerSample, blockAlign, channels, samplesPerSecond)
+		{
+		}
+
+		public abstract void Seek(uint sampleFrame);
+
+		protected override void OnReachedEnd()
+		{
+			if (Loop)
+			{
+				Seek(0);
+			}
+			else
+			{
+				Stop();
+			}
+		}
+	}
+}

src/Collision/Fixed/AABB2D.cs

@@ -0,0 +1,181 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// Axis-aligned bounding box.
+	/// </summary>
+	public struct AABB2D : System.IEquatable<AABB2D>
+	{
+		/// <summary>
+		/// The top-left position of the AABB.
+		/// </summary>
+		/// <value></value>
+		public Vector2 Min { get; private set; }
+
+		/// <summary>
+		/// The bottom-right position of the AABB.
+		/// </summary>
+		/// <value></value>
+		public Vector2 Max { get; private set; }
+
+		public Fix64 Width { get { return Max.X - Min.X; } }
+		public Fix64 Height { get { return Max.Y - Min.Y; } }
+
+		public Fix64 Right { get { return Max.X; } }
+		public Fix64 Left { get { return Min.X; } }
+
+		/// <summary>
+		/// The top of the AABB. Assumes a downward-aligned Y axis, so this value will be smaller than Bottom.
+		/// </summary>
+		/// <value></value>
+		public Fix64 Top { get { return Min.Y; } }
+
+		/// <summary>
+		/// The bottom of the AABB. Assumes a downward-aligned Y axis, so this value will be larger than Top.
+		/// </summary>
+		/// <value></value>
+		public Fix64 Bottom { get { return Max.Y; } }
+
+		public AABB2D(Fix64 minX, Fix64 minY, Fix64 maxX, Fix64 maxY)
+		{
+			Min = new Vector2(minX, minY);
+			Max = new Vector2(maxX, maxY);
+		}
+
+		public AABB2D(int minX, int minY, int maxX, int maxY)
+		{
+			Min = new Vector2(minX, minY);
+			Max = new Vector2(maxX, maxY);
+		}
+
+		public AABB2D(Vector2 min, Vector2 max)
+		{
+			Min = min;
+			Max = max;
+		}
+
+		private static Matrix3x2 AbsoluteMatrix(Matrix3x2 matrix)
+		{
+			return new Matrix3x2
+			(
+				Fix64.Abs(matrix.M11), Fix64.Abs(matrix.M12),
+				Fix64.Abs(matrix.M21), Fix64.Abs(matrix.M22),
+				Fix64.Abs(matrix.M31), Fix64.Abs(matrix.M32)
+			);
+		}
+
+		/// <summary>
+		/// Efficiently transforms the AABB by a Transform2D.
+		/// </summary>
+		/// <param name="aabb"></param>
+		/// <param name="transform"></param>
+		/// <returns></returns>
+		public static AABB2D Transformed(AABB2D aabb, Transform2D transform)
+		{
+			var two = new Fix64(2);
+			var center = (aabb.Min + aabb.Max) / two;
+            var extent = (aabb.Max - aabb.Min) / two;
+
+            var newCenter = Vector2.Transform(center, transform.TransformMatrix);
+            var newExtent = Vector2.TransformNormal(extent, AbsoluteMatrix(transform.TransformMatrix));
+
+            return new AABB2D(newCenter - newExtent, newCenter + newExtent);
+		}
+
+		public AABB2D Compose(AABB2D aabb)
+		{
+			Fix64 left = Left;
+			Fix64 top = Top;
+			Fix64 right = Right;
+			Fix64 bottom = Bottom;
+
+			if (aabb.Left < left)
+			{
+				left = aabb.Left;
+			}
+			if (aabb.Right > right)
+			{
+				right = aabb.Right;
+			}
+			if (aabb.Top < top)
+			{
+				top = aabb.Top;
+			}
+			if (aabb.Bottom > bottom)
+			{
+				bottom = aabb.Bottom;
+			}
+
+			return new AABB2D(left, top, right, bottom);
+		}
+
+		/// <summary>
+		/// Creates an AABB for an arbitrary collection of positions.
+		/// This is less efficient than defining a custom AABB method for most shapes, so avoid using this if possible.
+		/// </summary>
+		/// <param name="vertices"></param>
+		/// <returns></returns>
+		public static AABB2D FromVertices(IEnumerable<Vector2> vertices)
+		{
+			var minX = Fix64.MaxValue;
+			var minY = Fix64.MaxValue;
+			var maxX = Fix64.MinValue;
+			var maxY = Fix64.MinValue;
+
+			foreach (var vertex in vertices)
+			{
+				if (vertex.X < minX)
+				{
+					minX = vertex.X;
+				}
+				if (vertex.Y < minY)
+				{
+					minY = vertex.Y;
+				}
+				if (vertex.X > maxX)
+				{
+					maxX = vertex.X;
+				}
+				if (vertex.Y > maxY)
+				{
+					maxY = vertex.Y;
+				}
+			}
+
+			return new AABB2D(minX, minY, maxX, maxY);
+		}
+
+		public static bool TestOverlap(AABB2D a, AABB2D b)
+		{
+			return a.Left < b.Right && a.Right > b.Left && a.Top < b.Bottom && a.Bottom > b.Top;
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is AABB2D aabb && Equals(aabb);
+		}
+
+		public bool Equals(AABB2D other)
+		{
+			return Min == other.Min &&
+				   Max == other.Max;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Min, Max);
+		}
+
+		public static bool operator ==(AABB2D left, AABB2D right)
+		{
+			return left.Equals(right);
+		}
+
+		public static bool operator !=(AABB2D left, AABB2D right)
+		{
+			return !(left == right);
+		}
+	}
+}

src/Collision/Fixed/ICollidable.cs

@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	public interface ICollidable
+	{
+		IEnumerable<IShape2D> Shapes { get; }
+		AABB2D AABB { get; }
+		AABB2D TransformedAABB(Transform2D transform);
+	}
+}

src/Collision/Fixed/IShape2D.cs

@@ -0,0 +1,15 @@
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	public interface IShape2D : ICollidable, System.IEquatable<IShape2D>
+	{
+		/// <summary>
+		/// A Minkowski support function. Gives the farthest point on the edge of a shape along the given direction.
+		/// </summary>
+		/// <param name="direction">A normalized Vector2.</param>
+		/// <param name="transform">A Transform for transforming the shape vertices.</param>
+		/// <returns>The farthest point on the edge of the shape along the given direction.</returns>
+		Vector2 Support(Vector2 direction, Transform2D transform);
+	}
+}

src/Collision/Fixed/MinkowskiDifference.cs

@@ -0,0 +1,57 @@
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// A Minkowski difference between two shapes.
+	/// </summary>
+	public struct MinkowskiDifference : System.IEquatable<MinkowskiDifference>
+	{
+		private IShape2D ShapeA { get; }
+		private Transform2D TransformA { get; }
+		private IShape2D ShapeB { get; }
+		private Transform2D TransformB { get; }
+
+		public MinkowskiDifference(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
+		{
+			ShapeA = shapeA;
+			TransformA = transformA;
+			ShapeB = shapeB;
+			TransformB = transformB;
+		}
+
+		public Vector2 Support(Vector2 direction)
+		{
+			return ShapeA.Support(direction, TransformA) - ShapeB.Support(-direction, TransformB);
+		}
+
+		public override bool Equals(object other)
+		{
+			return other is MinkowskiDifference minkowskiDifference && Equals(minkowskiDifference);
+		}
+
+		public bool Equals(MinkowskiDifference other)
+		{
+			return
+				ShapeA == other.ShapeA &&
+				TransformA == other.TransformA &&
+				ShapeB == other.ShapeB &&
+				TransformB == other.TransformB;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(ShapeA, TransformA, ShapeB, TransformB);
+		}
+
+		public static bool operator ==(MinkowskiDifference a, MinkowskiDifference b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(MinkowskiDifference a, MinkowskiDifference b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Fixed/NarrowPhase.cs

@@ -0,0 +1,333 @@
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	public static class NarrowPhase
+	{
+		private struct Edge
+		{
+			public Fix64 Distance;
+			public Vector2 Normal;
+			public int Index;
+		}
+
+        public static bool TestCollision(ICollidable collidableA, Transform2D transformA, ICollidable collidableB, Transform2D transformB)
+        {
+            foreach (var shapeA in collidableA.Shapes)
+            {
+                foreach (var shapeB in collidableB.Shapes)
+                {
+					if (TestCollision(shapeA, transformA, shapeB, transformB))
+                    {
+						return true;
+					}
+				}
+            }
+
+			return false;
+		}
+
+		public static bool TestCollision(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
+		{
+			// If we can use a fast path check, let's do that!
+			if (shapeA is Rectangle rectangleA && shapeB is Rectangle rectangleB && transformA.IsAxisAligned && transformB.IsAxisAligned)
+			{
+				return TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB);
+			}
+			else if (shapeA is Point && shapeB is Rectangle && transformB.IsAxisAligned)
+			{
+				return TestPointRectangleOverlap((Point) shapeA, transformA, (Rectangle) shapeB, transformB);
+			}
+			else if (shapeA is Rectangle && shapeB is Point && transformA.IsAxisAligned)
+			{
+				return TestPointRectangleOverlap((Point) shapeB, transformB, (Rectangle) shapeA, transformA);
+			}
+			else if (shapeA is Rectangle && shapeB is Circle && transformA.IsAxisAligned && transformB.IsUniformScale)
+			{
+				return TestCircleRectangleOverlap((Circle) shapeB, transformB, (Rectangle) shapeA, transformA);
+			}
+			else if (shapeA is Circle && shapeB is Rectangle && transformA.IsUniformScale && transformB.IsAxisAligned)
+			{
+				return TestCircleRectangleOverlap((Circle) shapeA, transformA, (Rectangle) shapeB, transformB);
+			}
+			else if (shapeA is Circle && shapeB is Point && transformA.IsUniformScale)
+			{
+				return TestCirclePointOverlap((Circle) shapeA, transformA, (Point) shapeB, transformB);
+			}
+			else if (shapeA is Point && shapeB is Circle && transformB.IsUniformScale)
+			{
+				return TestCirclePointOverlap((Circle) shapeB, transformB, (Point) shapeA, transformA);
+			}
+			else if (shapeA is Circle circleA && shapeB is Circle circleB && transformA.IsUniformScale && transformB.IsUniformScale)
+			{
+				return TestCircleOverlap(circleA, transformA, circleB, transformB);
+			}
+
+			// Sad, we can't do a fast path optimization. Time for a simplex reduction.
+			return FindCollisionSimplex(shapeA, transformA, shapeB, transformB).Item1;
+		}
+
+		public static bool TestRectangleOverlap(Rectangle rectangleA, Transform2D transformA, Rectangle rectangleB, Transform2D transformB)
+		{
+			var firstAABB = rectangleA.TransformedAABB(transformA);
+			var secondAABB = rectangleB.TransformedAABB(transformB);
+
+			return firstAABB.Left < secondAABB.Right && firstAABB.Right > secondAABB.Left && firstAABB.Top < secondAABB.Bottom && firstAABB.Bottom > secondAABB.Top;
+		}
+
+		public static bool TestPointRectangleOverlap(Point point, Transform2D pointTransform, Rectangle rectangle, Transform2D rectangleTransform)
+		{
+			var transformedPoint = pointTransform.Position;
+			var AABB = rectangle.TransformedAABB(rectangleTransform);
+
+			return transformedPoint.X > AABB.Left && transformedPoint.X < AABB.Right && transformedPoint.Y < AABB.Bottom && transformedPoint.Y > AABB.Top;
+		}
+
+		public static bool TestCirclePointOverlap(Circle circle, Transform2D circleTransform, Point point, Transform2D pointTransform)
+		{
+			var circleCenter = circleTransform.Position;
+			var circleRadius = circle.Radius * circleTransform.Scale.X;
+
+			var distanceX = circleCenter.X - pointTransform.Position.X;
+			var distanceY = circleCenter.Y - pointTransform.Position.Y;
+
+			return (distanceX * distanceX) + (distanceY * distanceY) < (circleRadius * circleRadius);
+		}
+
+		/// <summary>
+		/// NOTE: The rectangle must be axis aligned, and the scaling of the circle must be uniform.
+		/// </summary>
+		public static bool TestCircleRectangleOverlap(Circle circle, Transform2D circleTransform, Rectangle rectangle, Transform2D rectangleTransform)
+		{
+			var circleCenter = circleTransform.Position;
+			var circleRadius = circle.Radius * circleTransform.Scale.X;
+			var AABB = rectangle.TransformedAABB(rectangleTransform);
+
+			var closestX = Fix64.Clamp(circleCenter.X, AABB.Left, AABB.Right);
+			var closestY = Fix64.Clamp(circleCenter.Y, AABB.Top, AABB.Bottom);
+
+			var distanceX = circleCenter.X - closestX;
+			var distanceY = circleCenter.Y - closestY;
+
+			var distanceSquared = (distanceX * distanceX) + (distanceY * distanceY);
+			return distanceSquared < (circleRadius * circleRadius);
+		}
+
+		public static bool TestCircleOverlap(Circle circleA, Transform2D transformA, Circle circleB, Transform2D transformB)
+		{
+			var radiusA = circleA.Radius * transformA.Scale.X;
+			var radiusB = circleB.Radius * transformB.Scale.Y;
+
+			var centerA = transformA.Position;
+			var centerB = transformB.Position;
+
+			var distanceSquared = (centerA - centerB).LengthSquared();
+			var radiusSumSquared = (radiusA + radiusB) * (radiusA + radiusB);
+
+			return distanceSquared < radiusSumSquared;
+		}
+
+		public static (bool, Simplex2D) FindCollisionSimplex(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
+		{
+			var minkowskiDifference = new MinkowskiDifference(shapeA, transformA, shapeB, transformB);
+			var c = minkowskiDifference.Support(Vector2.UnitX);
+			var b = minkowskiDifference.Support(-Vector2.UnitX);
+			return Check(minkowskiDifference, c, b);
+		}
+
+        public unsafe static Vector2 Intersect(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Simplex2D simplex)
+        {
+            if (shapeA == null) { throw new System.ArgumentNullException(nameof(shapeA)); }
+            if (shapeB == null) { throw new System.ArgumentNullException(nameof(shapeB)); }
+            if (!simplex.TwoSimplex) { throw new System.ArgumentException("Simplex must be a 2-Simplex.", nameof(simplex)); }
+
+			var epsilon = Fix64.FromFraction(1, 10000);
+
+			var a = simplex.A;
+            var b = simplex.B.Value;
+            var c = simplex.C.Value;
+
+            Vector2 intersection = default;
+
+            for (var i = 0; i < 32; i++)
+            {
+                var edge = FindClosestEdge(simplex);
+                var support = CalculateSupport(shapeA, Transform2DA, shapeB, Transform2DB, edge.Normal);
+                var distance = Vector2.Dot(support, edge.Normal);
+
+                intersection = edge.Normal;
+                intersection *= distance;
+
+                if (Fix64.Abs(distance - edge.Distance) <= epsilon)
+                {
+                    return intersection;
+                }
+                else
+                {
+					simplex.Insert(support, edge.Index);
+                }
+            }
+
+            return intersection; // close enough
+        }
+
+        private static unsafe Edge FindClosestEdge(Simplex2D simplex)
+        {
+			var closestDistance = Fix64.MaxValue;
+            var closestNormal = Vector2.Zero;
+            var closestIndex = 0;
+
+			for (var i = 0; i < 4; i += 1)
+			{
+				var j = (i + 1 == 3) ? 0 : i + 1;
+
+				var a = simplex[i];
+				var b = simplex[j];
+
+				var e = b - a;
+
+				var oa = a;
+
+				var n = Vector2.Normalize(TripleProduct(e, oa, e));
+
+				var d = Vector2.Dot(n, a);
+
+				if (d < closestDistance)
+				{
+					closestDistance = d;
+					closestNormal = n;
+					closestIndex = j;
+				}
+			}
+
+            return new Edge
+			{
+				Distance = closestDistance,
+				Normal = closestNormal,
+				Index = closestIndex
+			};
+        }
+
+        private static Vector2 CalculateSupport(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Vector2 direction)
+        {
+            return shapeA.Support(direction, Transform2DA) - shapeB.Support(-direction, Transform2DB);
+        }
+
+		private static (bool, Simplex2D) Check(MinkowskiDifference minkowskiDifference, Vector2 c, Vector2 b)
+        {
+            var cb = c - b;
+            var c0 = -c;
+            var d = Direction(cb, c0);
+            return DoSimplex(minkowskiDifference, new Simplex2D(b, c), d);
+        }
+
+        private static (bool, Simplex2D) DoSimplex(MinkowskiDifference minkowskiDifference, Simplex2D simplex, Vector2 direction)
+        {
+            var a = minkowskiDifference.Support(direction);
+            var notPastOrigin = Vector2.Dot(a, direction) < Fix64.Zero;
+            var (intersects, newSimplex, newDirection) = EnclosesOrigin(a, simplex);
+
+            if (notPastOrigin)
+            {
+                return (false, default(Simplex2D));
+            }
+            else if (intersects)
+            {
+                return (true, new Simplex2D(simplex.A, simplex.B.Value, a));
+            }
+            else
+            {
+                return DoSimplex(minkowskiDifference, newSimplex, newDirection);
+            }
+        }
+
+        private static (bool, Simplex2D, Vector2) EnclosesOrigin(Vector2 a, Simplex2D simplex)
+        {
+            if (simplex.ZeroSimplex)
+            {
+                return HandleZeroSimplex(a, simplex.A);
+            }
+            else if (simplex.OneSimplex)
+            {
+                return HandleOneSimplex(a, simplex.A, simplex.B.Value);
+            }
+            else
+            {
+                return (false, simplex, Vector2.Zero);
+            }
+        }
+
+        private static (bool, Simplex2D, Vector2) HandleZeroSimplex(Vector2 a, Vector2 b)
+        {
+            var ab = b - a;
+            var a0 = -a;
+            var (newSimplex, newDirection) = SameDirection(ab, a0) ? (new Simplex2D(a, b), Perpendicular(ab, a0)) : (new Simplex2D(a), a0);
+            return (false, newSimplex, newDirection);
+        }
+
+        private static (bool, Simplex2D, Vector2) HandleOneSimplex(Vector2 a, Vector2 b, Vector2 c)
+        {
+            var a0 = -a;
+            var ab = b - a;
+            var ac = c - a;
+            var abp = Perpendicular(ab, -ac);
+            var acp = Perpendicular(ac, -ab);
+
+            if (SameDirection(abp, a0))
+            {
+                if (SameDirection(ab, a0))
+                {
+                    return (false, new Simplex2D(a, b), abp);
+                }
+                else
+                {
+                    return (false, new Simplex2D(a), a0);
+                }
+            }
+            else if (SameDirection(acp, a0))
+            {
+                if (SameDirection(ac, a0))
+                {
+                    return (false, new Simplex2D(a, c), acp);
+                }
+                else
+                {
+                    return (false, new Simplex2D(a), a0);
+                }
+            }
+            else
+            {
+                return (true, new Simplex2D(b, c), a0);
+            }
+        }
+
+        private static Vector2 TripleProduct(Vector2 a, Vector2 b, Vector2 c)
+        {
+            var A = new Vector3(a.X, a.Y, Fix64.Zero);
+            var B = new Vector3(b.X, b.Y, Fix64.Zero);
+            var C = new Vector3(c.X, c.Y, Fix64.Zero);
+
+            var first = Vector3.Cross(A, B);
+            var second = Vector3.Cross(first, C);
+
+            return new Vector2(second.X, second.Y);
+        }
+
+        private static Vector2 Direction(Vector2 a, Vector2 b)
+        {
+            var d = TripleProduct(a, b, a);
+            var collinear = d == Vector2.Zero;
+            return collinear ? new Vector2(a.Y, -a.X) : d;
+        }
+
+        private static bool SameDirection(Vector2 a, Vector2 b)
+        {
+            return Vector2.Dot(a, b) > Fix64.Zero;
+        }
+
+        private static Vector2 Perpendicular(Vector2 a, Vector2 b)
+        {
+            return TripleProduct(a, b, a);
+        }
+	}
+}

src/Collision/Fixed/Shapes/Circle.cs

@@ -0,0 +1,73 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// A Circle is a shape defined by a radius.
+	/// </summary>
+	public struct Circle : IShape2D, System.IEquatable<Circle>
+	{
+		public Fix64 Radius { get; }
+		public AABB2D AABB { get; }
+		public IEnumerable<IShape2D> Shapes
+		{
+			get
+			{
+				yield return this;
+			}
+		}
+
+		public Circle(Fix64 radius)
+		{
+			Radius = radius;
+			AABB = new AABB2D(-Radius, -Radius, Radius, Radius);
+		}
+
+		public Circle(int radius)
+		{
+			Radius = (Fix64) radius;
+			AABB = new AABB2D(-Radius, -Radius, Radius, Radius);
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			return Vector2.Transform(Vector2.Normalize(direction) * Radius, transform.TransformMatrix);
+		}
+
+		public AABB2D TransformedAABB(Transform2D transform2D)
+		{
+			return AABB2D.Transformed(AABB, transform2D);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is IShape2D other && Equals(other);
+		}
+
+		public bool Equals(IShape2D other)
+		{
+			return other is Circle circle && Equals(circle);
+		}
+
+		public bool Equals(Circle other)
+		{
+			return Radius == other.Radius;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Radius);
+		}
+
+		public static bool operator ==(Circle a, Circle b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Circle a, Circle b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Fixed/Shapes/Line.cs

@@ -0,0 +1,83 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+    /// A line is a shape defined by exactly two points in space.
+    /// </summary>
+    public struct Line : IShape2D, System.IEquatable<Line>
+    {
+        public Vector2 Start { get; }
+        public Vector2 End { get; }
+
+        public AABB2D AABB { get; }
+
+		public IEnumerable<IShape2D> Shapes
+        {
+            get
+            {
+				yield return this;
+			}
+        }
+
+		public Line(Vector2 start, Vector2 end)
+        {
+            Start = start;
+            End = end;
+
+            AABB = new AABB2D(
+				Fix64.Min(Start.X, End.X),
+				Fix64.Min(Start.Y, End.Y),
+				Fix64.Max(Start.X, End.X),
+				Fix64.Max(Start.Y, End.Y)
+			);
+        }
+
+        public Vector2 Support(Vector2 direction, Transform2D transform)
+        {
+            var transformedStart = Vector2.Transform(Start, transform.TransformMatrix);
+            var transformedEnd = Vector2.Transform(End, transform.TransformMatrix);
+            return Vector2.Dot(transformedStart, direction) > Vector2.Dot(transformedEnd, direction) ?
+                transformedStart :
+                transformedEnd;
+        }
+
+        public AABB2D TransformedAABB(Transform2D transform)
+        {
+            return AABB2D.Transformed(AABB, transform);
+        }
+
+        public override bool Equals(object obj)
+        {
+            return obj is IShape2D other && Equals(other);
+        }
+
+        public bool Equals(IShape2D other)
+        {
+            return other is Line otherLine && Equals(otherLine);
+        }
+
+        public bool Equals(Line other)
+        {
+            return
+				(Start == other.Start && End == other.End) ||
+				(End == other.Start && Start == other.End);
+        }
+
+        public override int GetHashCode()
+        {
+            return System.HashCode.Combine(Start, End);
+        }
+
+        public static bool operator ==(Line a, Line b)
+        {
+            return a.Equals(b);
+        }
+
+        public static bool operator !=(Line a, Line b)
+        {
+            return !(a == b);
+        }
+    }
+}

src/Collision/Fixed/Shapes/Point.cs

@@ -0,0 +1,61 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// A Point is "that which has no part".
+	/// All points by themselves are identical.
+	/// </summary>
+	public struct Point : IShape2D, System.IEquatable<Point>
+	{
+		public AABB2D AABB { get; }
+		public IEnumerable<IShape2D> Shapes
+        {
+            get
+            {
+				yield return this;
+			}
+        }
+
+		public AABB2D TransformedAABB(Transform2D transform)
+		{
+			return AABB2D.Transformed(AABB, transform);
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			return Vector2.Transform(Vector2.Zero, transform.TransformMatrix);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is IShape2D other && Equals(other);
+		}
+
+		public bool Equals(IShape2D other)
+		{
+			return other is Point otherPoint && Equals(otherPoint);
+		}
+
+		public bool Equals(Point other)
+		{
+			return true;
+		}
+
+		public override int GetHashCode()
+		{
+			return 0;
+		}
+
+		public static bool operator ==(Point a, Point b)
+		{
+			return true;
+		}
+
+		public static bool operator !=(Point a, Point b)
+		{
+			return false;
+		}
+	}
+}

src/Collision/Fixed/Shapes/Rectangle.cs

@@ -0,0 +1,130 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// A rectangle is a shape defined by a width and height. The origin is the center of the rectangle.
+	/// </summary>
+	public struct Rectangle : IShape2D, System.IEquatable<Rectangle>
+	{
+		public AABB2D AABB { get; }
+		public Fix64 Width { get; }
+		public Fix64 Height { get; }
+
+		public Fix64 Right { get; }
+		public Fix64 Left { get; }
+		public Fix64 Top { get; }
+		public Fix64 Bottom { get; }
+		public Vector2 TopLeft { get; }
+		public Vector2 BottomRight { get; }
+
+		public Vector2 Min { get; }
+		public Vector2 Max { get; }
+
+		public IEnumerable<IShape2D> Shapes
+        {
+            get
+            {
+				yield return this;
+			}
+        }
+
+		public Rectangle(Fix64 left, Fix64 top, Fix64 width, Fix64 height)
+		{
+			Width = width;
+			Height = height;
+			Left = left;
+			Right = left + width;
+			Top = top;
+			Bottom = top + height;
+			AABB = new AABB2D(left, top, Right, Bottom);
+			TopLeft = new Vector2(Left, Top);
+			BottomRight = new Vector2(Right, Bottom);
+			Min = AABB.Min;
+			Max = AABB.Max;
+		}
+
+		public Rectangle(int left, int top, int width, int height)
+		{
+			Width = (Fix64) width;
+			Height = (Fix64) height;
+			Left = (Fix64) left;
+			Right = (Fix64) (left + width);
+			Top = (Fix64) top;
+			Bottom = (Fix64) (top + height);
+			AABB = new AABB2D(Left, Top, Right, Bottom);
+			TopLeft = new Vector2(Left, Top);
+			BottomRight = new Vector2(Right, Bottom);
+			Min = AABB.Min;
+			Max = AABB.Max;
+		}
+
+		private Vector2 Support(Vector2 direction)
+		{
+			if (direction.X >= Fix64.Zero && direction.Y >= Fix64.Zero)
+			{
+				return Max;
+			}
+			else if (direction.X >= Fix64.Zero && direction.Y < Fix64.Zero)
+			{
+				return new Vector2(Max.X, Min.Y);
+			}
+			else if (direction.X < Fix64.Zero && direction.Y >= Fix64.Zero)
+			{
+				return new Vector2(Min.X, Max.Y);
+			}
+			else if (direction.X < Fix64.Zero && direction.Y < Fix64.Zero)
+			{
+				return new Vector2(Min.X, Min.Y);
+			}
+			else
+			{
+				throw new System.ArgumentException("Support vector direction cannot be zero.");
+			}
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			Matrix3x2 inverseTransform;
+			Matrix3x2.Invert(transform.TransformMatrix, out inverseTransform);
+			var inverseDirection = Vector2.TransformNormal(direction, inverseTransform);
+			return Vector2.Transform(Support(inverseDirection), transform.TransformMatrix);
+		}
+
+		public AABB2D TransformedAABB(Transform2D transform)
+		{
+			return AABB2D.Transformed(AABB, transform);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is IShape2D other && Equals(other);
+		}
+
+		public bool Equals(IShape2D other)
+		{
+			return (other is Rectangle rectangle && Equals(rectangle));
+		}
+
+		public bool Equals(Rectangle other)
+		{
+			return Min == other.Min && Max == other.Max;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Min, Max);
+		}
+
+		public static bool operator ==(Rectangle a, Rectangle b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Rectangle a, Rectangle b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Fixed/Simplex2D.cs

@@ -0,0 +1,136 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// A simplex is a shape with up to n - 2 vertices in the nth dimension.
+	/// </summary>
+	public struct Simplex2D : System.IEquatable<Simplex2D>
+	{
+		private Vector2 a;
+		private Vector2? b;
+		private Vector2? c;
+
+		public Vector2 A => a;
+		public Vector2? B => b;
+		public Vector2? C => c;
+
+		public bool ZeroSimplex { get { return !b.HasValue && !c.HasValue; } }
+		public bool OneSimplex { get { return b.HasValue && !c.HasValue; } }
+		public bool TwoSimplex { get { return b.HasValue && c.HasValue; } }
+
+		public int Count => TwoSimplex ? 3 : (OneSimplex ? 2 : 1);
+
+		public Simplex2D(Vector2 a)
+		{
+			this.a = a;
+			b = null;
+			c = null;
+		}
+
+		public Simplex2D(Vector2 a, Vector2 b)
+		{
+			this.a = a;
+			this.b = b;
+			c = null;
+		}
+
+		public Simplex2D(Vector2 a, Vector2 b, Vector2 c)
+		{
+			this.a = a;
+			this.b = b;
+			this.c = c;
+		}
+
+		public Vector2 this[int index]
+		{
+			get
+			{
+				if (index == 0) { return a; }
+				if (index == 1) { return b.Value; }
+				if (index == 2) { return c.Value; }
+				throw new System.IndexOutOfRangeException();
+			}
+		}
+
+		public IEnumerable<Vector2> Vertices
+		{
+			get
+			{
+				yield return (Vector2) a;
+				if (b.HasValue) { yield return (Vector2) b; }
+				if (c.HasValue) { yield return (Vector2) c; }
+			}
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			var maxDotProduct = Fix64.MinValue;
+			var maxVertex = a;
+			foreach (var vertex in Vertices)
+			{
+				var transformed = Vector2.Transform(vertex, transform.TransformMatrix);
+				var dot = Vector2.Dot(transformed, direction);
+				if (dot > maxDotProduct)
+				{
+					maxVertex = transformed;
+					maxDotProduct = dot;
+				}
+			}
+			return maxVertex;
+		}
+
+		public void Insert(Vector2 point, int index)
+		{
+			if (index == 0)
+			{
+				c = b;
+				b = a;
+				a = point;
+			}
+			else if (index == 1)
+			{
+				c = b;
+				b = point;
+			}
+			else
+			{
+				c = point;
+			}
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is Simplex2D other && Equals(other);
+		}
+
+		public bool Equals(Simplex2D other)
+		{
+			if (Count != other.Count) { return false; }
+
+			return
+				(A == other.A && B == other.B && C == other.C) ||
+				(A == other.A && B == other.C && C == other.B) ||
+				(A == other.B && B == other.A && C == other.C) ||
+				(A == other.B && B == other.C && C == other.A) ||
+				(A == other.C && B == other.A && C == other.B) ||
+				(A == other.C && B == other.B && C == other.A);
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Vertices);
+		}
+
+		public static bool operator ==(Simplex2D a, Simplex2D b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Simplex2D a, Simplex2D b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Fixed/SpatialHash2D.cs

@@ -0,0 +1,252 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Fixed;
+
+namespace MoonWorks.Collision.Fixed
+{
+	/// <summary>
+	/// Used to quickly check if two shapes are potentially overlapping.
+	/// </summary>
+	/// <typeparam name="T">The type that will be used to uniquely identify shape-transform pairs.</typeparam>
+	public class SpatialHash2D<T> where T : System.IEquatable<T>
+	{
+		private readonly Fix64 cellSize;
+
+		private readonly Dictionary<long, HashSet<T>> hashDictionary = new Dictionary<long, HashSet<T>>();
+		private readonly Dictionary<T, (ICollidable, Transform2D, uint)> IDLookup = new Dictionary<T, (ICollidable, Transform2D, uint)>();
+
+		public int MinX { get; private set; } = 0;
+		public int MaxX { get; private set; } = 0;
+		public int MinY { get; private set; } = 0;
+		public int MaxY { get; private set; } = 0;
+
+		private Queue<HashSet<T>> hashSetPool = new Queue<HashSet<T>>();
+
+		public SpatialHash2D(int cellSize)
+		{
+			this.cellSize = new Fix64(cellSize);
+		}
+
+		private (int, int) Hash(Vector2 position)
+		{
+			return ((int) (position.X / cellSize), (int) (position.Y / cellSize));
+		}
+
+		/// <summary>
+		/// Inserts an element into the SpatialHash.
+		/// </summary>
+		/// <param name="id">A unique ID for the shape-transform pair.</param>
+		/// <param name="shape"></param>
+		/// <param name="transform2D"></param>
+		/// <param name="collisionGroups">A bitmask value specifying the groups this object belongs to.</param>
+		public void Insert(T id, ICollidable shape, Transform2D transform2D, uint collisionGroups = uint.MaxValue)
+		{
+			var box = shape.TransformedAABB(transform2D);
+			var minHash = Hash(box.Min);
+			var maxHash = Hash(box.Max);
+
+			foreach (var key in Keys(minHash.Item1, minHash.Item2, maxHash.Item1, maxHash.Item2))
+			{
+				if (!hashDictionary.ContainsKey(key))
+				{
+					hashDictionary.Add(key, new HashSet<T>());
+				}
+
+				hashDictionary[key].Add(id);
+				IDLookup[id] = (shape, transform2D, collisionGroups);
+			}
+
+			MinX = System.Math.Min(MinX, minHash.Item1);
+			MinY = System.Math.Min(MinY, minHash.Item2);
+			MaxX = System.Math.Max(MaxX, maxHash.Item1);
+			MaxY = System.Math.Max(MaxY, maxHash.Item2);
+		}
+
+		/// <summary>
+		/// Retrieves all the potential collisions of a shape-transform pair. Excludes any shape-transforms with the given ID.
+		/// </summary>
+		public IEnumerable<(T, ICollidable, Transform2D, uint)> Retrieve(T id, ICollidable shape, Transform2D transform2D, uint collisionMask = uint.MaxValue)
+		{
+			var returned = AcquireHashSet();
+
+			var box = shape.TransformedAABB(transform2D);
+			var (minX, minY) = Hash(box.Min);
+			var (maxX, maxY) = Hash(box.Max);
+
+			if (minX < MinX) { minX = MinX; }
+			if (maxX > MaxX) { maxX = MaxX; }
+			if (minY < MinY) { minY = MinY; }
+			if (maxY > MaxY) { maxY = MaxY; }
+
+			foreach (var key in Keys(minX, minY, maxX, maxY))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					foreach (var t in hashDictionary[key])
+					{
+						if (!returned.Contains(t))
+						{
+							var (otherShape, otherTransform, collisionGroups) = IDLookup[t];
+							if (!id.Equals(t) && ((collisionGroups & collisionMask) > 0) && AABB2D.TestOverlap(box, otherShape.TransformedAABB(otherTransform)))
+							{
+								returned.Add(t);
+								yield return (t, otherShape, otherTransform, collisionGroups);
+							}
+						}
+					}
+				}
+			}
+
+			FreeHashSet(returned);
+		}
+
+		/// <summary>
+		/// Retrieves all the potential collisions of a shape-transform pair.
+		/// </summary>
+		public IEnumerable<(T, ICollidable, Transform2D, uint)> Retrieve(ICollidable shape, Transform2D transform2D, uint collisionMask = uint.MaxValue)
+		{
+			var returned = AcquireHashSet();
+
+			var box = shape.TransformedAABB(transform2D);
+			var (minX, minY) = Hash(box.Min);
+			var (maxX, maxY) = Hash(box.Max);
+
+			if (minX < MinX) { minX = MinX; }
+			if (maxX > MaxX) { maxX = MaxX; }
+			if (minY < MinY) { minY = MinY; }
+			if (maxY > MaxY) { maxY = MaxY; }
+
+			foreach (var key in Keys(minX, minY, maxX, maxY))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					foreach (var t in hashDictionary[key])
+					{
+						if (!returned.Contains(t))
+						{
+							var (otherShape, otherTransform, collisionGroups) = IDLookup[t];
+							if (((collisionGroups & collisionMask) > 0) && AABB2D.TestOverlap(box, otherShape.TransformedAABB(otherTransform)))
+							{
+								returned.Add(t);
+								yield return (t, otherShape, otherTransform, collisionGroups);
+							}
+						}
+					}
+				}
+			}
+
+			FreeHashSet(returned);
+		}
+
+		/// <summary>
+		/// Retrieves objects based on a pre-transformed AABB.
+		/// </summary>
+		/// <param name="aabb">A transformed AABB.</param>
+		/// <returns></returns>
+		public IEnumerable<(T, ICollidable, Transform2D, uint)> Retrieve(AABB2D aabb, uint collisionMask = uint.MaxValue)
+		{
+			var returned = AcquireHashSet();
+
+			var (minX, minY) = Hash(aabb.Min);
+			var (maxX, maxY) = Hash(aabb.Max);
+
+			if (minX < MinX) { minX = MinX; }
+			if (maxX > MaxX) { maxX = MaxX; }
+			if (minY < MinY) { minY = MinY; }
+			if (maxY > MaxY) { maxY = MaxY; }
+
+			foreach (var key in Keys(minX, minY, maxX, maxY))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					foreach (var t in hashDictionary[key])
+					{
+						if (!returned.Contains(t))
+						{
+							var (otherShape, otherTransform, collisionGroups) = IDLookup[t];
+							if (((collisionGroups & collisionMask) > 0) && AABB2D.TestOverlap(aabb, otherShape.TransformedAABB(otherTransform)))
+							{
+								yield return (t, otherShape, otherTransform, collisionGroups);
+							}
+						}
+					}
+				}
+			}
+
+			FreeHashSet(returned);
+		}
+
+		public void Update(T id, ICollidable shape, Transform2D transform2D, uint collisionGroups = uint.MaxValue)
+		{
+			Remove(id);
+			Insert(id, shape, transform2D, collisionGroups);
+		}
+
+		/// <summary>
+		/// Removes a specific ID from the SpatialHash.
+		/// </summary>
+		public void Remove(T id)
+		{
+			var (shape, transform, collisionGroups) = IDLookup[id];
+
+			var box = shape.TransformedAABB(transform);
+			var minHash = Hash(box.Min);
+			var maxHash = Hash(box.Max);
+
+			foreach (var key in Keys(minHash.Item1, minHash.Item2, maxHash.Item1, maxHash.Item2))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					hashDictionary[key].Remove(id);
+				}
+			}
+
+			IDLookup.Remove(id);
+		}
+
+		/// <summary>
+		/// Removes everything that has been inserted into the SpatialHash.
+		/// </summary>
+		public void Clear()
+		{
+			foreach (var hash in hashDictionary.Values)
+			{
+				hash.Clear();
+			}
+
+			IDLookup.Clear();
+		}
+
+		private static long MakeLong(int left, int right)
+		{
+			return ((long) left << 32) | ((uint) right);
+		}
+
+		private IEnumerable<long> Keys(int minX, int minY, int maxX, int maxY)
+		{
+			for (var i = minX; i <= maxX; i++)
+			{
+				for (var j = minY; j <= maxY; j++)
+				{
+					yield return MakeLong(i, j);
+				}
+			}
+		}
+
+		private HashSet<T> AcquireHashSet()
+		{
+			if (hashSetPool.Count == 0)
+			{
+				hashSetPool.Enqueue(new HashSet<T>());
+			}
+
+			var hashSet = hashSetPool.Dequeue();
+			hashSet.Clear();
+			return hashSet;
+		}
+
+		private void FreeHashSet(HashSet<T> hashSet)
+		{
+			hashSetPool.Enqueue(hashSet);
+		}
+	}
+}

src/Collision/Float/AABB2D.cs

@@ -0,0 +1,174 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// Axis-aligned bounding box.
+	/// </summary>
+	public struct AABB2D : System.IEquatable<AABB2D>
+	{
+		/// <summary>
+		/// The top-left position of the AABB.
+		/// </summary>
+		/// <value></value>
+		public Vector2 Min { get; private set; }
+
+		/// <summary>
+		/// The bottom-right position of the AABB.
+		/// </summary>
+		/// <value></value>
+		public Vector2 Max { get; private set; }
+
+		public float Width { get { return Max.X - Min.X; } }
+		public float Height { get { return Max.Y - Min.Y; } }
+
+		public float Right { get { return Max.X; } }
+		public float Left { get { return Min.X; } }
+
+		/// <summary>
+		/// The top of the AABB. Assumes a downward-aligned Y axis, so this value will be smaller than Bottom.
+		/// </summary>
+		/// <value></value>
+		public float Top { get { return Min.Y; } }
+
+		/// <summary>
+		/// The bottom of the AABB. Assumes a downward-aligned Y axis, so this value will be larger than Top.
+		/// </summary>
+		/// <value></value>
+		public float Bottom { get { return Max.Y; } }
+
+		public AABB2D(float minX, float minY, float maxX, float maxY)
+		{
+			Min = new Vector2(minX, minY);
+			Max = new Vector2(maxX, maxY);
+		}
+
+		public AABB2D(Vector2 min, Vector2 max)
+		{
+			Min = min;
+			Max = max;
+		}
+
+		private static Matrix3x2 AbsoluteMatrix(Matrix3x2 matrix)
+		{
+			return new Matrix3x2
+			(
+				System.Math.Abs(matrix.M11), System.Math.Abs(matrix.M12),
+				System.Math.Abs(matrix.M21), System.Math.Abs(matrix.M22),
+				System.Math.Abs(matrix.M31), System.Math.Abs(matrix.M32)
+			);
+		}
+
+		/// <summary>
+		/// Efficiently transforms the AABB by a Transform2D.
+		/// </summary>
+		/// <param name="aabb"></param>
+		/// <param name="transform"></param>
+		/// <returns></returns>
+		public static AABB2D Transformed(AABB2D aabb, Transform2D transform)
+		{
+            var center = (aabb.Min + aabb.Max) / 2f;
+            var extent = (aabb.Max - aabb.Min) / 2f;
+
+            var newCenter = Vector2.Transform(center, transform.TransformMatrix);
+            var newExtent = Vector2.TransformNormal(extent, AbsoluteMatrix(transform.TransformMatrix));
+
+            return new AABB2D(newCenter - newExtent, newCenter + newExtent);
+		}
+
+		public AABB2D Compose(AABB2D aabb)
+		{
+			float left = Left;
+			float top = Top;
+			float right = Right;
+			float bottom = Bottom;
+
+			if (aabb.Left < left)
+			{
+				left = aabb.Left;
+			}
+			if (aabb.Right > right)
+			{
+				right = aabb.Right;
+			}
+			if (aabb.Top < top)
+			{
+				top = aabb.Top;
+			}
+			if (aabb.Bottom > bottom)
+			{
+				bottom = aabb.Bottom;
+			}
+
+			return new AABB2D(left, top, right, bottom);
+		}
+
+		/// <summary>
+		/// Creates an AABB for an arbitrary collection of positions.
+		/// This is less efficient than defining a custom AABB method for most shapes, so avoid using this if possible.
+		/// </summary>
+		/// <param name="vertices"></param>
+		/// <returns></returns>
+		public static AABB2D FromVertices(IEnumerable<Vector2> vertices)
+		{
+			var minX = float.MaxValue;
+			var minY = float.MaxValue;
+			var maxX = float.MinValue;
+			var maxY = float.MinValue;
+
+			foreach (var vertex in vertices)
+			{
+				if (vertex.X < minX)
+				{
+					minX = vertex.X;
+				}
+				if (vertex.Y < minY)
+				{
+					minY = vertex.Y;
+				}
+				if (vertex.X > maxX)
+				{
+					maxX = vertex.X;
+				}
+				if (vertex.Y > maxY)
+				{
+					maxY = vertex.Y;
+				}
+			}
+
+			return new AABB2D(minX, minY, maxX, maxY);
+		}
+
+		public static bool TestOverlap(AABB2D a, AABB2D b)
+		{
+			return a.Left < b.Right && a.Right > b.Left && a.Top < b.Bottom && a.Bottom > b.Top;
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is AABB2D aabb && Equals(aabb);
+		}
+
+		public bool Equals(AABB2D other)
+		{
+			return Min == other.Min &&
+				   Max == other.Max;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Min, Max);
+		}
+
+		public static bool operator ==(AABB2D left, AABB2D right)
+		{
+			return left.Equals(right);
+		}
+
+		public static bool operator !=(AABB2D left, AABB2D right)
+		{
+			return !(left == right);
+		}
+	}
+}

src/Collision/Float/ICollidable.cs

@@ -0,0 +1,12 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	public interface ICollidable
+	{
+		IEnumerable<IShape2D> Shapes { get; }
+		AABB2D AABB { get; }
+		AABB2D TransformedAABB(Transform2D transform);
+	}
+}

src/Collision/Float/IShape2D.cs

@@ -0,0 +1,15 @@
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	public interface IShape2D : ICollidable, System.IEquatable<IShape2D>
+	{
+		/// <summary>
+		/// A Minkowski support function. Gives the farthest point on the edge of a shape along the given direction.
+		/// </summary>
+		/// <param name="direction">A normalized Vector2.</param>
+		/// <param name="transform">A Transform for transforming the shape vertices.</param>
+		/// <returns>The farthest point on the edge of the shape along the given direction.</returns>
+		Vector2 Support(Vector2 direction, Transform2D transform);
+	}
+}

src/Collision/Float/MinkowskiDifference.cs

@@ -0,0 +1,57 @@
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// A Minkowski difference between two shapes.
+	/// </summary>
+	public struct MinkowskiDifference : System.IEquatable<MinkowskiDifference>
+	{
+		private IShape2D ShapeA { get; }
+		private Transform2D TransformA { get; }
+		private IShape2D ShapeB { get; }
+		private Transform2D TransformB { get; }
+
+		public MinkowskiDifference(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
+		{
+			ShapeA = shapeA;
+			TransformA = transformA;
+			ShapeB = shapeB;
+			TransformB = transformB;
+		}
+
+		public Vector2 Support(Vector2 direction)
+		{
+			return ShapeA.Support(direction, TransformA) - ShapeB.Support(-direction, TransformB);
+		}
+
+		public override bool Equals(object other)
+		{
+			return other is MinkowskiDifference minkowskiDifference && Equals(minkowskiDifference);
+		}
+
+		public bool Equals(MinkowskiDifference other)
+		{
+			return
+				ShapeA == other.ShapeA &&
+				TransformA == other.TransformA &&
+				ShapeB == other.ShapeB &&
+				TransformB == other.TransformB;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(ShapeA, TransformA, ShapeB, TransformB);
+		}
+
+		public static bool operator ==(MinkowskiDifference a, MinkowskiDifference b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(MinkowskiDifference a, MinkowskiDifference b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Float/NarrowPhase.cs

@@ -0,0 +1,331 @@
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	public static class NarrowPhase
+	{
+		private struct Edge
+		{
+			public float Distance;
+			public Vector2 Normal;
+			public int Index;
+		}
+
+        public static bool TestCollision(ICollidable collidableA, Transform2D transformA, ICollidable collidableB, Transform2D transformB)
+        {
+            foreach (var shapeA in collidableA.Shapes)
+            {
+                foreach (var shapeB in collidableB.Shapes)
+                {
+					if (TestCollision(shapeA, transformA, shapeB, transformB))
+                    {
+						return true;
+					}
+				}
+            }
+
+			return false;
+		}
+
+		public static bool TestCollision(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
+		{
+			// If we can use a fast path check, let's do that!
+			if (shapeA is Rectangle rectangleA && shapeB is Rectangle rectangleB && transformA.IsAxisAligned && transformB.IsAxisAligned)
+			{
+				return TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB);
+			}
+			else if (shapeA is Point && shapeB is Rectangle && transformB.IsAxisAligned)
+			{
+				return TestPointRectangleOverlap((Point) shapeA, transformA, (Rectangle) shapeB, transformB);
+			}
+			else if (shapeA is Rectangle && shapeB is Point && transformA.IsAxisAligned)
+			{
+				return TestPointRectangleOverlap((Point) shapeB, transformB, (Rectangle) shapeA, transformA);
+			}
+			else if (shapeA is Rectangle && shapeB is Circle && transformA.IsAxisAligned && transformB.IsUniformScale)
+			{
+				return TestCircleRectangleOverlap((Circle) shapeB, transformB, (Rectangle) shapeA, transformA);
+			}
+			else if (shapeA is Circle && shapeB is Rectangle && transformA.IsUniformScale && transformB.IsAxisAligned)
+			{
+				return TestCircleRectangleOverlap((Circle) shapeA, transformA, (Rectangle) shapeB, transformB);
+			}
+			else if (shapeA is Circle && shapeB is Point && transformA.IsUniformScale)
+			{
+				return TestCirclePointOverlap((Circle) shapeA, transformA, (Point) shapeB, transformB);
+			}
+			else if (shapeA is Point && shapeB is Circle && transformB.IsUniformScale)
+			{
+				return TestCirclePointOverlap((Circle) shapeB, transformB, (Point) shapeA, transformA);
+			}
+			else if (shapeA is Circle circleA && shapeB is Circle circleB && transformA.IsUniformScale && transformB.IsUniformScale)
+			{
+				return TestCircleOverlap(circleA, transformA, circleB, transformB);
+			}
+
+			// Sad, we can't do a fast path optimization. Time for a simplex reduction.
+			return FindCollisionSimplex(shapeA, transformA, shapeB, transformB).Item1;
+		}
+
+		public static bool TestRectangleOverlap(Rectangle rectangleA, Transform2D transformA, Rectangle rectangleB, Transform2D transformB)
+		{
+			var firstAABB = rectangleA.TransformedAABB(transformA);
+			var secondAABB = rectangleB.TransformedAABB(transformB);
+
+			return firstAABB.Left < secondAABB.Right && firstAABB.Right > secondAABB.Left && firstAABB.Top < secondAABB.Bottom && firstAABB.Bottom > secondAABB.Top;
+		}
+
+		public static bool TestPointRectangleOverlap(Point point, Transform2D pointTransform, Rectangle rectangle, Transform2D rectangleTransform)
+		{
+			var transformedPoint = pointTransform.Position;
+			var AABB = rectangle.TransformedAABB(rectangleTransform);
+
+			return transformedPoint.X > AABB.Left && transformedPoint.X < AABB.Right && transformedPoint.Y < AABB.Bottom && transformedPoint.Y > AABB.Top;
+		}
+
+		public static bool TestCirclePointOverlap(Circle circle, Transform2D circleTransform, Point point, Transform2D pointTransform)
+		{
+			var circleCenter = circleTransform.Position;
+			var circleRadius = circle.Radius * circleTransform.Scale.X;
+
+			var distanceX = circleCenter.X - pointTransform.Position.X;
+			var distanceY = circleCenter.Y - pointTransform.Position.Y;
+
+			return (distanceX * distanceX) + (distanceY * distanceY) < (circleRadius * circleRadius);
+		}
+
+		/// <summary>
+		/// NOTE: The rectangle must be axis aligned, and the scaling of the circle must be uniform.
+		/// </summary>
+		public static bool TestCircleRectangleOverlap(Circle circle, Transform2D circleTransform, Rectangle rectangle, Transform2D rectangleTransform)
+		{
+			var circleCenter = circleTransform.Position;
+			var circleRadius = circle.Radius * circleTransform.Scale.X;
+			var AABB = rectangle.TransformedAABB(rectangleTransform);
+
+			var closestX = Math.MathHelper.Clamp(circleCenter.X, AABB.Left, AABB.Right);
+			var closestY = Math.MathHelper.Clamp(circleCenter.Y, AABB.Top, AABB.Bottom);
+
+			var distanceX = circleCenter.X - closestX;
+			var distanceY = circleCenter.Y - closestY;
+
+			var distanceSquared = (distanceX * distanceX) + (distanceY * distanceY);
+			return distanceSquared < (circleRadius * circleRadius);
+		}
+
+		public static bool TestCircleOverlap(Circle circleA, Transform2D transformA, Circle circleB, Transform2D transformB)
+		{
+			var radiusA = circleA.Radius * transformA.Scale.X;
+			var radiusB = circleB.Radius * transformB.Scale.Y;
+
+			var centerA = transformA.Position;
+			var centerB = transformB.Position;
+
+			var distanceSquared = (centerA - centerB).LengthSquared();
+			var radiusSumSquared = (radiusA + radiusB) * (radiusA + radiusB);
+
+			return distanceSquared < radiusSumSquared;
+		}
+
+		public static (bool, Simplex2D) FindCollisionSimplex(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
+		{
+			var minkowskiDifference = new MinkowskiDifference(shapeA, transformA, shapeB, transformB);
+			var c = minkowskiDifference.Support(Vector2.UnitX);
+			var b = minkowskiDifference.Support(-Vector2.UnitX);
+			return Check(minkowskiDifference, c, b);
+		}
+
+        public unsafe static Vector2 Intersect(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Simplex2D simplex)
+        {
+            if (shapeA == null) { throw new System.ArgumentNullException(nameof(shapeA)); }
+            if (shapeB == null) { throw new System.ArgumentNullException(nameof(shapeB)); }
+            if (!simplex.TwoSimplex) { throw new System.ArgumentException("Simplex must be a 2-Simplex.", nameof(simplex)); }
+
+            var a = simplex.A;
+            var b = simplex.B.Value;
+            var c = simplex.C.Value;
+
+            Vector2 intersection = default;
+
+            for (var i = 0; i < 32; i++)
+            {
+                var edge = FindClosestEdge(simplex);
+                var support = CalculateSupport(shapeA, Transform2DA, shapeB, Transform2DB, edge.Normal);
+                var distance = Vector2.Dot(support, edge.Normal);
+
+                intersection = edge.Normal;
+                intersection *= distance;
+
+                if (System.Math.Abs(distance - edge.Distance) <= 0.00001f)
+                {
+                    return intersection;
+                }
+                else
+                {
+					simplex.Insert(support, edge.Index);
+                }
+            }
+
+            return intersection; // close enough
+        }
+
+        private static unsafe Edge FindClosestEdge(Simplex2D simplex)
+        {
+            var closestDistance = float.PositiveInfinity;
+            var closestNormal = Vector2.Zero;
+            var closestIndex = 0;
+
+			for (var i = 0; i < 4; i += 1)
+			{
+				var j = (i + 1 == 3) ? 0 : i + 1;
+
+				var a = simplex[i];
+				var b = simplex[j];
+
+				var e = b - a;
+
+				var oa = a;
+
+				var n = Vector2.Normalize(TripleProduct(e, oa, e));
+
+				var d = Vector2.Dot(n, a);
+
+				if (d < closestDistance)
+				{
+					closestDistance = d;
+					closestNormal = n;
+					closestIndex = j;
+				}
+			}
+
+            return new Edge
+			{
+				Distance = closestDistance,
+				Normal = closestNormal,
+				Index = closestIndex
+			};
+        }
+
+        private static Vector2 CalculateSupport(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Vector2 direction)
+        {
+            return shapeA.Support(direction, Transform2DA) - shapeB.Support(-direction, Transform2DB);
+        }
+
+		private static (bool, Simplex2D) Check(MinkowskiDifference minkowskiDifference, Vector2 c, Vector2 b)
+        {
+            var cb = c - b;
+            var c0 = -c;
+            var d = Direction(cb, c0);
+            return DoSimplex(minkowskiDifference, new Simplex2D(b, c), d);
+        }
+
+        private static (bool, Simplex2D) DoSimplex(MinkowskiDifference minkowskiDifference, Simplex2D simplex, Vector2 direction)
+        {
+            var a = minkowskiDifference.Support(direction);
+            var notPastOrigin = Vector2.Dot(a, direction) < 0;
+            var (intersects, newSimplex, newDirection) = EnclosesOrigin(a, simplex);
+
+            if (notPastOrigin)
+            {
+                return (false, default(Simplex2D));
+            }
+            else if (intersects)
+            {
+                return (true, new Simplex2D(simplex.A, simplex.B.Value, a));
+            }
+            else
+            {
+                return DoSimplex(minkowskiDifference, newSimplex, newDirection);
+            }
+        }
+
+        private static (bool, Simplex2D, Vector2) EnclosesOrigin(Vector2 a, Simplex2D simplex)
+        {
+            if (simplex.ZeroSimplex)
+            {
+                return HandleZeroSimplex(a, simplex.A);
+            }
+            else if (simplex.OneSimplex)
+            {
+                return HandleOneSimplex(a, simplex.A, simplex.B.Value);
+            }
+            else
+            {
+                return (false, simplex, Vector2.Zero);
+            }
+        }
+
+        private static (bool, Simplex2D, Vector2) HandleZeroSimplex(Vector2 a, Vector2 b)
+        {
+            var ab = b - a;
+            var a0 = -a;
+            var (newSimplex, newDirection) = SameDirection(ab, a0) ? (new Simplex2D(a, b), Perpendicular(ab, a0)) : (new Simplex2D(a), a0);
+            return (false, newSimplex, newDirection);
+        }
+
+        private static (bool, Simplex2D, Vector2) HandleOneSimplex(Vector2 a, Vector2 b, Vector2 c)
+        {
+            var a0 = -a;
+            var ab = b - a;
+            var ac = c - a;
+            var abp = Perpendicular(ab, -ac);
+            var acp = Perpendicular(ac, -ab);
+
+            if (SameDirection(abp, a0))
+            {
+                if (SameDirection(ab, a0))
+                {
+                    return (false, new Simplex2D(a, b), abp);
+                }
+                else
+                {
+                    return (false, new Simplex2D(a), a0);
+                }
+            }
+            else if (SameDirection(acp, a0))
+            {
+                if (SameDirection(ac, a0))
+                {
+                    return (false, new Simplex2D(a, c), acp);
+                }
+                else
+                {
+                    return (false, new Simplex2D(a), a0);
+                }
+            }
+            else
+            {
+                return (true, new Simplex2D(b, c), a0);
+            }
+        }
+
+        private static Vector2 TripleProduct(Vector2 a, Vector2 b, Vector2 c)
+        {
+            var A = new Vector3(a.X, a.Y, 0);
+            var B = new Vector3(b.X, b.Y, 0);
+            var C = new Vector3(c.X, c.Y, 0);
+
+            var first = Vector3.Cross(A, B);
+            var second = Vector3.Cross(first, C);
+
+            return new Vector2(second.X, second.Y);
+        }
+
+        private static Vector2 Direction(Vector2 a, Vector2 b)
+        {
+            var d = TripleProduct(a, b, a);
+            var collinear = d == Vector2.Zero;
+            return collinear ? new Vector2(a.Y, -a.X) : d;
+        }
+
+        private static bool SameDirection(Vector2 a, Vector2 b)
+        {
+            return Vector2.Dot(a, b) > 0;
+        }
+
+        private static Vector2 Perpendicular(Vector2 a, Vector2 b)
+        {
+            return TripleProduct(a, b, a);
+        }
+	}
+}

src/Collision/Float/Shapes/Circle.cs

@@ -0,0 +1,67 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// A Circle is a shape defined by a radius.
+	/// </summary>
+	public struct Circle : IShape2D, System.IEquatable<Circle>
+	{
+		public float Radius { get; }
+		public AABB2D AABB { get; }
+		public IEnumerable<IShape2D> Shapes
+		{
+			get
+			{
+				yield return this;
+			}
+		}
+
+		public Circle(float radius)
+		{
+			Radius = radius;
+			AABB = new AABB2D(-Radius, -Radius, Radius, Radius);
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			return Vector2.Transform(Vector2.Normalize(direction) * Radius, transform.TransformMatrix);
+		}
+
+		public AABB2D TransformedAABB(Transform2D transform2D)
+		{
+			return AABB2D.Transformed(AABB, transform2D);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is IShape2D other && Equals(other);
+		}
+
+		public bool Equals(IShape2D other)
+		{
+			return other is Circle circle && Equals(circle);
+		}
+
+		public bool Equals(Circle other)
+		{
+			return Radius == other.Radius;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Radius);
+		}
+
+		public static bool operator ==(Circle a, Circle b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Circle a, Circle b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Float/Shapes/Line.cs

@@ -0,0 +1,83 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+    /// A line is a shape defined by exactly two points in space.
+    /// </summary>
+    public struct Line : IShape2D, System.IEquatable<Line>
+    {
+        public Vector2 Start { get; }
+        public Vector2 End { get; }
+
+        public AABB2D AABB { get; }
+
+		public IEnumerable<IShape2D> Shapes
+        {
+            get
+            {
+				yield return this;
+			}
+        }
+
+		public Line(Vector2 start, Vector2 end)
+        {
+            Start = start;
+            End = end;
+
+            AABB = new AABB2D(
+				System.Math.Min(Start.X, End.X),
+				System.Math.Min(Start.Y, End.Y),
+				System.Math.Max(Start.X, End.X),
+				System.Math.Max(Start.Y, End.Y)
+			);
+        }
+
+        public Vector2 Support(Vector2 direction, Transform2D transform)
+        {
+            var transformedStart = Vector2.Transform(Start, transform.TransformMatrix);
+            var transformedEnd = Vector2.Transform(End, transform.TransformMatrix);
+            return Vector2.Dot(transformedStart, direction) > Vector2.Dot(transformedEnd, direction) ?
+                transformedStart :
+                transformedEnd;
+        }
+
+        public AABB2D TransformedAABB(Transform2D transform)
+        {
+            return AABB2D.Transformed(AABB, transform);
+        }
+
+        public override bool Equals(object obj)
+        {
+            return obj is IShape2D other && Equals(other);
+        }
+
+        public bool Equals(IShape2D other)
+        {
+            return other is Line otherLine && Equals(otherLine);
+        }
+
+        public bool Equals(Line other)
+        {
+            return
+				(Start == other.Start && End == other.End) ||
+				(End == other.Start && Start == other.End);
+        }
+
+        public override int GetHashCode()
+        {
+            return System.HashCode.Combine(Start, End);
+        }
+
+        public static bool operator ==(Line a, Line b)
+        {
+            return a.Equals(b);
+        }
+
+        public static bool operator !=(Line a, Line b)
+        {
+            return !(a == b);
+        }
+    }
+}

src/Collision/Float/Shapes/Point.cs

@@ -0,0 +1,61 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// A Point is "that which has no part".
+	/// All points by themselves are identical.
+	/// </summary>
+	public struct Point : IShape2D, System.IEquatable<Point>
+	{
+		public AABB2D AABB { get; }
+		public IEnumerable<IShape2D> Shapes
+        {
+            get
+            {
+				yield return this;
+			}
+        }
+
+		public AABB2D TransformedAABB(Transform2D transform)
+		{
+			return AABB2D.Transformed(AABB, transform);
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			return Vector2.Transform(Vector2.Zero, transform.TransformMatrix);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is IShape2D other && Equals(other);
+		}
+
+		public bool Equals(IShape2D other)
+		{
+			return other is Point otherPoint && Equals(otherPoint);
+		}
+
+		public bool Equals(Point other)
+		{
+			return true;
+		}
+
+		public override int GetHashCode()
+		{
+			return 0;
+		}
+
+		public static bool operator ==(Point a, Point b)
+		{
+			return true;
+		}
+
+		public static bool operator !=(Point a, Point b)
+		{
+			return false;
+		}
+	}
+}

src/Collision/Float/Shapes/Rectangle.cs

@@ -0,0 +1,115 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// A rectangle is a shape defined by a width and height. The origin is the center of the rectangle.
+	/// </summary>
+	public struct Rectangle : IShape2D, System.IEquatable<Rectangle>
+	{
+		public AABB2D AABB { get; }
+		public float Width { get; }
+		public float Height { get; }
+
+		public float Right { get; }
+		public float Left { get; }
+		public float Top { get; }
+		public float Bottom { get; }
+		public Vector2 TopLeft { get; }
+		public Vector2 BottomRight { get; }
+
+		public Vector2 Min { get; }
+		public Vector2 Max { get; }
+
+		public IEnumerable<IShape2D> Shapes
+        {
+            get
+            {
+				yield return this;
+			}
+        }
+
+		public Rectangle(float left, float top, float width, float height)
+		{
+			Width = width;
+			Height = height;
+			Left = left;
+			Right = left + width;
+			Top = top;
+			Bottom = top + height;
+			AABB = new AABB2D(left, top, Right, Bottom);
+			TopLeft = new Vector2(Left, Top);
+			BottomRight = new Vector2(Right, Bottom);
+			Min = AABB.Min;
+			Max = AABB.Max;
+		}
+
+		private Vector2 Support(Vector2 direction)
+		{
+			if (direction.X >= 0 && direction.Y >= 0)
+			{
+				return Max;
+			}
+			else if (direction.X >= 0 && direction.Y < 0)
+			{
+				return new Vector2(Max.X, Min.Y);
+			}
+			else if (direction.X < 0 && direction.Y >= 0)
+			{
+				return new Vector2(Min.X, Max.Y);
+			}
+			else if (direction.X < 0 && direction.Y < 0)
+			{
+				return new Vector2(Min.X, Min.Y);
+			}
+			else
+			{
+				throw new System.ArgumentException("Support vector direction cannot be zero.");
+			}
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			Matrix3x2 inverseTransform;
+			Matrix3x2.Invert(transform.TransformMatrix, out inverseTransform);
+			var inverseDirection = Vector2.TransformNormal(direction, inverseTransform);
+			return Vector2.Transform(Support(inverseDirection), transform.TransformMatrix);
+		}
+
+		public AABB2D TransformedAABB(Transform2D transform)
+		{
+			return AABB2D.Transformed(AABB, transform);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is IShape2D other && Equals(other);
+		}
+
+		public bool Equals(IShape2D other)
+		{
+			return (other is Rectangle rectangle && Equals(rectangle));
+		}
+
+		public bool Equals(Rectangle other)
+		{
+			return Min == other.Min && Max == other.Max;
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Min, Max);
+		}
+
+		public static bool operator ==(Rectangle a, Rectangle b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Rectangle a, Rectangle b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Float/Simplex2D.cs

@@ -0,0 +1,136 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// A simplex is a shape with up to n - 2 vertices in the nth dimension.
+	/// </summary>
+	public struct Simplex2D : System.IEquatable<Simplex2D>
+	{
+		private Vector2 a;
+		private Vector2? b;
+		private Vector2? c;
+
+		public Vector2 A => a;
+		public Vector2? B => b;
+		public Vector2? C => c;
+
+		public bool ZeroSimplex { get { return !b.HasValue && !c.HasValue; } }
+		public bool OneSimplex { get { return b.HasValue && !c.HasValue; } }
+		public bool TwoSimplex { get { return b.HasValue && c.HasValue; } }
+
+		public int Count => TwoSimplex ? 3 : (OneSimplex ? 2 : 1);
+
+		public Simplex2D(Vector2 a)
+		{
+			this.a = a;
+			b = null;
+			c = null;
+		}
+
+		public Simplex2D(Vector2 a, Vector2 b)
+		{
+			this.a = a;
+			this.b = b;
+			c = null;
+		}
+
+		public Simplex2D(Vector2 a, Vector2 b, Vector2 c)
+		{
+			this.a = a;
+			this.b = b;
+			this.c = c;
+		}
+
+		public Vector2 this[int index]
+		{
+			get
+			{
+				if (index == 0) { return a; }
+				if (index == 1) { return b.Value; }
+				if (index == 2) { return c.Value; }
+				throw new System.IndexOutOfRangeException();
+			}
+		}
+
+		public IEnumerable<Vector2> Vertices
+		{
+			get
+			{
+				yield return (Vector2) a;
+				if (b.HasValue) { yield return (Vector2) b; }
+				if (c.HasValue) { yield return (Vector2) c; }
+			}
+		}
+
+		public Vector2 Support(Vector2 direction, Transform2D transform)
+		{
+			var maxDotProduct = float.NegativeInfinity;
+			var maxVertex = a;
+			foreach (var vertex in Vertices)
+			{
+				var transformed = Vector2.Transform(vertex, transform.TransformMatrix);
+				var dot = Vector2.Dot(transformed, direction);
+				if (dot > maxDotProduct)
+				{
+					maxVertex = transformed;
+					maxDotProduct = dot;
+				}
+			}
+			return maxVertex;
+		}
+
+		public void Insert(Vector2 point, int index)
+		{
+			if (index == 0)
+			{
+				c = b;
+				b = a;
+				a = point;
+			}
+			else if (index == 1)
+			{
+				c = b;
+				b = point;
+			}
+			else
+			{
+				c = point;
+			}
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is Simplex2D other && Equals(other);
+		}
+
+		public bool Equals(Simplex2D other)
+		{
+			if (Count != other.Count) { return false; }
+
+			return
+				(A == other.A && B == other.B && C == other.C) ||
+				(A == other.A && B == other.C && C == other.B) ||
+				(A == other.B && B == other.A && C == other.C) ||
+				(A == other.B && B == other.C && C == other.A) ||
+				(A == other.C && B == other.A && C == other.B) ||
+				(A == other.C && B == other.B && C == other.A);
+		}
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Vertices);
+		}
+
+		public static bool operator ==(Simplex2D a, Simplex2D b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Simplex2D a, Simplex2D b)
+		{
+			return !(a == b);
+		}
+	}
+}

src/Collision/Float/SpatialHash2D.cs

@@ -0,0 +1,252 @@
+using System.Collections.Generic;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Collision.Float
+{
+	/// <summary>
+	/// Used to quickly check if two shapes are potentially overlapping.
+	/// </summary>
+	/// <typeparam name="T">The type that will be used to uniquely identify shape-transform pairs.</typeparam>
+	public class SpatialHash2D<T> where T : System.IEquatable<T>
+	{
+		private readonly int cellSize;
+
+		private readonly Dictionary<long, HashSet<T>> hashDictionary = new Dictionary<long, HashSet<T>>();
+		private readonly Dictionary<T, (ICollidable, Transform2D, uint)> IDLookup = new Dictionary<T, (ICollidable, Transform2D, uint)>();
+
+		public int MinX { get; private set; } = 0;
+		public int MaxX { get; private set; } = 0;
+		public int MinY { get; private set; } = 0;
+		public int MaxY { get; private set; } = 0;
+
+		private Queue<HashSet<T>> hashSetPool = new Queue<HashSet<T>>();
+
+		public SpatialHash2D(int cellSize)
+		{
+			this.cellSize = cellSize;
+		}
+
+		private (int, int) Hash(Vector2 position)
+		{
+			return ((int) System.Math.Floor(position.X / cellSize), (int) System.Math.Floor(position.Y / cellSize));
+		}
+
+		/// <summary>
+		/// Inserts an element into the SpatialHash.
+		/// </summary>
+		/// <param name="id">A unique ID for the shape-transform pair.</param>
+		/// <param name="shape"></param>
+		/// <param name="transform2D"></param>
+		/// <param name="collisionGroups">A bitmask value specifying the groups this object belongs to.</param>
+		public void Insert(T id, ICollidable shape, Transform2D transform2D, uint collisionGroups = uint.MaxValue)
+		{
+			var box = shape.TransformedAABB(transform2D);
+			var minHash = Hash(box.Min);
+			var maxHash = Hash(box.Max);
+
+			foreach (var key in Keys(minHash.Item1, minHash.Item2, maxHash.Item1, maxHash.Item2))
+			{
+				if (!hashDictionary.ContainsKey(key))
+				{
+					hashDictionary.Add(key, new HashSet<T>());
+				}
+
+				hashDictionary[key].Add(id);
+				IDLookup[id] = (shape, transform2D, collisionGroups);
+			}
+
+			MinX = System.Math.Min(MinX, minHash.Item1);
+			MinY = System.Math.Min(MinY, minHash.Item2);
+			MaxX = System.Math.Max(MaxX, maxHash.Item1);
+			MaxY = System.Math.Max(MaxY, maxHash.Item2);
+		}
+
+		/// <summary>
+		/// Retrieves all the potential collisions of a shape-transform pair. Excludes any shape-transforms with the given ID.
+		/// </summary>
+		public IEnumerable<(T, ICollidable, Transform2D, uint)> Retrieve(T id, ICollidable shape, Transform2D transform2D, uint collisionMask = uint.MaxValue)
+		{
+			var returned = AcquireHashSet();
+
+			var box = shape.TransformedAABB(transform2D);
+			var (minX, minY) = Hash(box.Min);
+			var (maxX, maxY) = Hash(box.Max);
+
+			if (minX < MinX) { minX = MinX; }
+			if (maxX > MaxX) { maxX = MaxX; }
+			if (minY < MinY) { minY = MinY; }
+			if (maxY > MaxY) { maxY = MaxY; }
+
+			foreach (var key in Keys(minX, minY, maxX, maxY))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					foreach (var t in hashDictionary[key])
+					{
+						if (!returned.Contains(t))
+						{
+							var (otherShape, otherTransform, collisionGroups) = IDLookup[t];
+							if (!id.Equals(t) && ((collisionGroups & collisionMask) > 0) && AABB2D.TestOverlap(box, otherShape.TransformedAABB(otherTransform)))
+							{
+								returned.Add(t);
+								yield return (t, otherShape, otherTransform, collisionGroups);
+							}
+						}
+					}
+				}
+			}
+
+			FreeHashSet(returned);
+		}
+
+		/// <summary>
+		/// Retrieves all the potential collisions of a shape-transform pair.
+		/// </summary>
+		public IEnumerable<(T, ICollidable, Transform2D, uint)> Retrieve(ICollidable shape, Transform2D transform2D, uint collisionMask = uint.MaxValue)
+		{
+			var returned = AcquireHashSet();
+
+			var box = shape.TransformedAABB(transform2D);
+			var (minX, minY) = Hash(box.Min);
+			var (maxX, maxY) = Hash(box.Max);
+
+			if (minX < MinX) { minX = MinX; }
+			if (maxX > MaxX) { maxX = MaxX; }
+			if (minY < MinY) { minY = MinY; }
+			if (maxY > MaxY) { maxY = MaxY; }
+
+			foreach (var key in Keys(minX, minY, maxX, maxY))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					foreach (var t in hashDictionary[key])
+					{
+						if (!returned.Contains(t))
+						{
+							var (otherShape, otherTransform, collisionGroups) = IDLookup[t];
+							if (((collisionGroups & collisionMask) > 0) && AABB2D.TestOverlap(box, otherShape.TransformedAABB(otherTransform)))
+							{
+								returned.Add(t);
+								yield return (t, otherShape, otherTransform, collisionGroups);
+							}
+						}
+					}
+				}
+			}
+
+			FreeHashSet(returned);
+		}
+
+		/// <summary>
+		/// Retrieves objects based on a pre-transformed AABB.
+		/// </summary>
+		/// <param name="aabb">A transformed AABB.</param>
+		/// <returns></returns>
+		public IEnumerable<(T, ICollidable, Transform2D, uint)> Retrieve(AABB2D aabb, uint collisionMask = uint.MaxValue)
+		{
+			var returned = AcquireHashSet();
+
+			var (minX, minY) = Hash(aabb.Min);
+			var (maxX, maxY) = Hash(aabb.Max);
+
+			if (minX < MinX) { minX = MinX; }
+			if (maxX > MaxX) { maxX = MaxX; }
+			if (minY < MinY) { minY = MinY; }
+			if (maxY > MaxY) { maxY = MaxY; }
+
+			foreach (var key in Keys(minX, minY, maxX, maxY))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					foreach (var t in hashDictionary[key])
+					{
+						if (!returned.Contains(t))
+						{
+							var (otherShape, otherTransform, collisionGroups) = IDLookup[t];
+							if (((collisionGroups & collisionMask) > 0) && AABB2D.TestOverlap(aabb, otherShape.TransformedAABB(otherTransform)))
+							{
+								yield return (t, otherShape, otherTransform, collisionGroups);
+							}
+						}
+					}
+				}
+			}
+
+			FreeHashSet(returned);
+		}
+
+		public void Update(T id, ICollidable shape, Transform2D transform2D, uint collisionGroups = uint.MaxValue)
+		{
+			Remove(id);
+			Insert(id, shape, transform2D, collisionGroups);
+		}
+
+		/// <summary>
+		/// Removes a specific ID from the SpatialHash.
+		/// </summary>
+		public void Remove(T id)
+		{
+			var (shape, transform, collisionGroups) = IDLookup[id];
+
+			var box = shape.TransformedAABB(transform);
+			var minHash = Hash(box.Min);
+			var maxHash = Hash(box.Max);
+
+			foreach (var key in Keys(minHash.Item1, minHash.Item2, maxHash.Item1, maxHash.Item2))
+			{
+				if (hashDictionary.ContainsKey(key))
+				{
+					hashDictionary[key].Remove(id);
+				}
+			}
+
+			IDLookup.Remove(id);
+		}
+
+		/// <summary>
+		/// Removes everything that has been inserted into the SpatialHash.
+		/// </summary>
+		public void Clear()
+		{
+			foreach (var hash in hashDictionary.Values)
+			{
+				hash.Clear();
+			}
+
+			IDLookup.Clear();
+		}
+
+		private static long MakeLong(int left, int right)
+		{
+			return ((long) left << 32) | ((uint) right);
+		}
+
+		private IEnumerable<long> Keys(int minX, int minY, int maxX, int maxY)
+		{
+			for (var i = minX; i <= maxX; i++)
+			{
+				for (var j = minY; j <= maxY; j++)
+				{
+					yield return MakeLong(i, j);
+				}
+			}
+		}
+
+		private HashSet<T> AcquireHashSet()
+		{
+			if (hashSetPool.Count == 0)
+			{
+				hashSetPool.Enqueue(new HashSet<T>());
+			}
+
+			var hashSet = hashSetPool.Dequeue();
+			hashSet.Clear();
+			return hashSet;
+		}
+
+		private void FreeHashSet(HashSet<T> hashSet)
+		{
+			hashSetPool.Enqueue(hashSet);
+		}
+	}
+}

src/FramerateSettings.cs

@@ -0,0 +1,14 @@
+namespace MoonWorks
+{
+	public enum FramerateMode
+	{
+		Uncapped,
+		Capped
+	}
+
+	public struct FramerateSettings
+	{
+		public FramerateMode Mode;
+		public int Cap;
+	}
+}

src/Game.cs

@@ -3,7 +3,6 @@ using SDL2;
 using MoonWorks.Audio;
 using MoonWorks.Graphics;
 using MoonWorks.Input;
-using MoonWorks.Window;
 using System.Text;
 using System;
 using System.Diagnostics;
@@ -13,14 +12,13 @@ namespace MoonWorks
 	public abstract class Game
 	{
 		public TimeSpan MAX_DELTA_TIME = TimeSpan.FromMilliseconds(100);
+		public TimeSpan Timestep { get; private set; }
 
 		private bool quit = false;
-		bool debugMode;
-
 		private Stopwatch gameTimer;
-		private TimeSpan timestep;
 		private long previousTicks = 0;
-		TimeSpan accumulatedElapsedTime = TimeSpan.Zero;
+		TimeSpan accumulatedUpdateTime = TimeSpan.Zero;
+		TimeSpan accumulatedDrawTime = TimeSpan.Zero;
 		// must be a power of 2 so we can do a bitmask optimization when checking worst case
 		private const int PREVIOUS_SLEEP_TIME_COUNT = 128;
 		private const int SLEEP_TIME_MASK = PREVIOUS_SLEEP_TIME_COUNT - 1;
@@ -28,7 +26,10 @@ namespace MoonWorks
 		private int sleepTimeIndex = 0;
 		private TimeSpan worstCaseSleepPrecision = TimeSpan.FromMilliseconds(1);
 
-		public OSWindow Window { get; }
+		private bool FramerateCapped = false;
+		private TimeSpan FramerateCapTimeSpan = TimeSpan.Zero;
+
+		public Window Window { get; }
 		public GraphicsDevice GraphicsDevice { get; }
 		public AudioDevice AudioDevice { get; }
 		public Inputs Inputs { get; }
@@ -44,13 +45,21 @@ namespace MoonWorks
 		public Game(
 			WindowCreateInfo windowCreateInfo,
 			PresentMode presentMode,
+			FramerateSettings framerateSettings,
 			int targetTimestep = 60,
 			bool debugMode = false
 		)
 		{
-			timestep = TimeSpan.FromTicks(TimeSpan.TicksPerSecond / targetTimestep);
+			Timestep = TimeSpan.FromTicks(TimeSpan.TicksPerSecond / targetTimestep);
 			gameTimer = Stopwatch.StartNew();
 
+			FramerateCapped = framerateSettings.Mode == FramerateMode.Capped;
+
+			if (FramerateCapped)
+			{
+				FramerateCapTimeSpan = TimeSpan.FromTicks(TimeSpan.TicksPerSecond / framerateSettings.Cap);
+			}
+
 			for (int i = 0; i < previousSleepTimes.Length; i += 1)
 			{
 				previousSleepTimes[i] = TimeSpan.FromMilliseconds(1);
@@ -66,7 +75,7 @@ namespace MoonWorks
 
 			Inputs = new Inputs();
 
-			Window = new OSWindow(windowCreateInfo);
+			Window = new Window(windowCreateInfo);
 
 			GraphicsDevice = new GraphicsDevice(
 				Window.Handle,
@@ -75,22 +84,51 @@ namespace MoonWorks
 			);
 
 			AudioDevice = new AudioDevice();
-
-			this.debugMode = debugMode;
 		}
 
 		public void Run()
 		{
 			while (!quit)
 			{
-				AdvanceElapsedTime();
+				Tick();
+			}
 
-				/* We want to wait until the next frame,
+			Destroy();
-				 * but we don't want to oversleep. Requesting repeated 1ms sleeps and
+
-				 * seeing how long we actually slept for lets us estimate the worst case
+			AudioDevice.Dispose();
-				 * sleep precision so we don't oversleep the next frame.
+			GraphicsDevice.Dispose();
-				 */
+			Window.Dispose();
-				while (accumulatedElapsedTime + worstCaseSleepPrecision < timestep)
+
+			SDL.SDL_Quit();
+		}
+
+		protected abstract void Update(TimeSpan delta);
+		protected abstract void Draw(double alpha);
+		protected virtual void Destroy() {}
+
+		// Called when a file is dropped on the game window.
+		protected virtual void DropFile(string filePath) {}
+
+		/* Required to distinguish between multiple files dropped at once
+		 * vs multiple files dropped one at a time.
+		 *
+		 * Called once for every multi-file drop.
+		 */
+		protected virtual void DropBegin() {}
+		protected virtual void DropComplete() {}
+
+		private void Tick()
+		{
+			AdvanceElapsedTime();
+
+			if (FramerateCapped)
+			{
+				/* We want to wait until the framerate cap,
+				* but we don't want to oversleep. Requesting repeated 1ms sleeps and
+				* seeing how long we actually slept for lets us estimate the worst case
+				* sleep precision so we don't oversleep the next frame.
+				*/
+				while (accumulatedDrawTime + worstCaseSleepPrecision < FramerateCapTimeSpan)
 				{
 					System.Threading.Thread.Sleep(1);
 					TimeSpan timeAdvancedSinceSleeping = AdvanceElapsedTime();
@@ -98,55 +136,43 @@ namespace MoonWorks
 				}
 
 				/* Now that we have slept into the sleep precision threshold, we need to wait
-				 * for just a little bit longer until the target elapsed time has been reached.
+				* for just a little bit longer until the target elapsed time has been reached.
-				 * SpinWait(1) works by pausing the thread for very short intervals, so it is
+				* SpinWait(1) works by pausing the thread for very short intervals, so it is
-				 * an efficient and time-accurate way to wait out the rest of the time.
+				* an efficient and time-accurate way to wait out the rest of the time.
-				 */
+				*/
-				while (accumulatedElapsedTime < timestep)
+				while (accumulatedDrawTime < FramerateCapTimeSpan)
 				{
 					System.Threading.Thread.SpinWait(1);
 					AdvanceElapsedTime();
 				}
-
-				// Now that we are going to perform an update, let's handle SDL events.
-				HandleSDLEvents();
-
-				// Do not let any step take longer than our maximum.
-				if (accumulatedElapsedTime > MAX_DELTA_TIME)
-				{
-					accumulatedElapsedTime = MAX_DELTA_TIME;
-				}
-
-				if (!quit)
-				{
-					while (accumulatedElapsedTime >= timestep)
-					{
-						Inputs.Mouse.Wheel = 0;
-
-						Inputs.Update();
-						AudioDevice.Update();
-
-						Update(timestep);
-
-						accumulatedElapsedTime -= timestep;
-					}
-
-					var alpha = accumulatedElapsedTime / timestep;
-
-					Draw(timestep, alpha);
-
-				}
-
-				GraphicsDevice.SubmitDestroyCommandBuffer();
 			}
 
-			OnDestroy();
+			// Now that we are going to perform an update, let's handle SDL events.
+			HandleSDLEvents();
 
-			AudioDevice.Dispose();
+			// Do not let any step take longer than our maximum.
-			GraphicsDevice.Dispose();
+			if (accumulatedUpdateTime > MAX_DELTA_TIME)
-			Window.Dispose();
+			{
+				accumulatedUpdateTime = MAX_DELTA_TIME;
+			}
 
-			SDL.SDL_Quit();
+			if (!quit)
+			{
+				while (accumulatedUpdateTime >= Timestep)
+				{
+					Inputs.Update();
+					AudioDevice.Update();
+
+					Update(Timestep);
+
+					accumulatedUpdateTime -= Timestep;
+				}
+
+				var alpha = accumulatedUpdateTime / Timestep;
+
+				Draw(alpha);
+				accumulatedDrawTime -= FramerateCapTimeSpan;
+			}
 		}
 
 		private void HandleSDLEvents()
@@ -166,19 +192,43 @@ namespace MoonWorks
 					case SDL.SDL_EventType.SDL_MOUSEWHEEL:
 						Inputs.Mouse.Wheel += _event.wheel.y;
 						break;
+
+					case SDL.SDL_EventType.SDL_DROPBEGIN:
+						DropBegin();
+						break;
+
+					case SDL.SDL_EventType.SDL_DROPCOMPLETE:
+						DropComplete();
+						break;
+
+					case SDL.SDL_EventType.SDL_DROPFILE:
+						HandleFileDrop(_event);
+						break;
+
+					case SDL.SDL_EventType.SDL_CONTROLLERDEVICEADDED:
+						HandleControllerAdded(_event);
+						break;
+
+					case SDL.SDL_EventType.SDL_CONTROLLERDEVICEREMOVED:
+						HandleControllerRemoved(_event);
+						break;
+
+					case SDL.SDL_EventType.SDL_WINDOWEVENT:
+						HandleWindowEvent(_event);
+						break;
 				}
 			}
 		}
 
-		protected abstract void Update(TimeSpan dt);
+		private void HandleWindowEvent(SDL.SDL_Event evt)
+		{
+			if (evt.window.windowEvent == SDL.SDL_WindowEventID.SDL_WINDOWEVENT_SIZE_CHANGED)
+			{
+				Window.SizeChanged((uint) evt.window.data1, (uint) evt.window.data2);
+			}
+		}
 
-		// alpha refers to a percentage value between the current and next state
+		private void HandleTextInput(SDL.SDL_Event evt)
-		protected abstract void Draw(TimeSpan dt, double alpha);
-
-		// Clean up any objects you created in this function
-		protected abstract void OnDestroy();
-
-		private void HandleTextInput(SDL2.SDL.SDL_Event evt)
 		{
 			// Based on the SDL2# LPUtf8StrMarshaler
 			unsafe
@@ -206,11 +256,35 @@ namespace MoonWorks
 			}
 		}
 
+		private void HandleFileDrop(SDL.SDL_Event evt)
+		{
+			// Need to do it this way because SDL2 expects you to free the filename string.
+			string filePath = SDL.UTF8_ToManaged(evt.drop.file, true);
+			DropFile(filePath);
+		}
+
+		private void HandleControllerAdded(SDL.SDL_Event evt)
+		{
+			var index = evt.cdevice.which;
+			if (SDL.SDL_IsGameController(index) == SDL.SDL_bool.SDL_TRUE)
+			{
+				System.Console.WriteLine($"New controller detected!");
+				Inputs.AddGamepad(index);
+			}
+		}
+
+		private void HandleControllerRemoved(SDL.SDL_Event evt)
+		{
+			System.Console.WriteLine($"Controller removal detected!");
+			Inputs.RemoveGamepad(evt.cdevice.which);
+		}
+
 		private TimeSpan AdvanceElapsedTime()
 		{
 			long currentTicks = gameTimer.Elapsed.Ticks;
 			TimeSpan timeAdvanced = TimeSpan.FromTicks(currentTicks - previousTicks);
-			accumulatedElapsedTime += timeAdvanced;
+			accumulatedUpdateTime += timeAdvanced;
+			accumulatedDrawTime += timeAdvanced;
 			previousTicks = currentTicks;
 			return timeAdvanced;
 		}

src/Graphics/Bindings/TextureSamplerBinding.cs

@@ -1,14 +1,22 @@
-namespace MoonWorks.Graphics
+using System;
+
+namespace MoonWorks.Graphics
 {
 	public struct TextureSamplerBinding
 	{
-		public Texture Texture;
+		public IntPtr TextureHandle;
-		public Sampler Sampler;
+		public IntPtr SamplerHandle;
 
 		public TextureSamplerBinding(Texture texture, Sampler sampler)
 		{
-			Texture = texture;
+			TextureHandle = texture.Handle;
-			Sampler = sampler;
+			SamplerHandle = sampler.Handle;
+		}
+
+		public TextureSamplerBinding(IntPtr textureHandle, IntPtr samplerHandle)
+		{
+			TextureHandle = textureHandle;
+			SamplerHandle = samplerHandle;
 		}
 	}
 }

src/Graphics/Color.cs

@@ -19,6 +19,7 @@ using System;
 using System.Diagnostics;
 using System.Text;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/CommandBuffer.cs

@@ -1,7 +1,4 @@
 using System;
-using System.Runtime.InteropServices;
-using MoonWorks.Math;
-using MoonWorks.Window;
 using RefreshCS;
 
 namespace MoonWorks.Graphics
@@ -22,6 +19,8 @@ namespace MoonWorks.Graphics
 			Handle = handle;
 		}
 
+		// FIXME: we can probably use the NativeMemory functions to not have to generate arrays here
+
 		/// <summary>
 		/// Begins a render pass.
 		/// All render state, resource binding, and draw commands must be made within a render pass.
@@ -58,7 +57,7 @@ namespace MoonWorks.Graphics
 				Refresh.Refresh_BeginRenderPass(
 					Device.Handle,
 					Handle,
-					colorAttachmentInfos[0].renderTarget.TextureSlice.Rectangle.ToRefresh(),
+					IntPtr.Zero,
 					(IntPtr) pColorAttachmentInfos,
 					(uint) colorAttachmentInfos.Length,
 					IntPtr.Zero
@@ -106,7 +105,7 @@ namespace MoonWorks.Graphics
 				Refresh.Refresh_BeginRenderPass(
 					Device.Handle,
 					Handle,
-					colorAttachmentInfos[0].renderTarget.TextureSlice.Rectangle.ToRefresh(),
+					IntPtr.Zero,
 					pColorAttachmentInfos,
 					(uint) colorAttachmentInfos.Length,
 					&refreshDepthStencilAttachmentInfo
@@ -308,6 +307,30 @@ namespace MoonWorks.Graphics
 			);
 		}
 
+		/// <summary>
+		/// Sets the viewport. Only valid during a render pass.
+		/// </summary>
+		public void SetViewport(Viewport viewport)
+		{
+			Refresh.Refresh_SetViewport(
+				Device.Handle,
+				Handle,
+				viewport.ToRefresh()
+			);
+		}
+
+		/// <summary>
+		/// Sets the scissor area. Only valid during a render pass.
+		/// </summary>
+		public void SetScissor(Rect scissor)
+		{
+			Refresh.Refresh_SetScissor(
+				Device.Handle,
+				Handle,
+				scissor.ToRefresh()
+			);
+		}
+
 		/// <summary>
 		/// Binds vertex buffers to be used by subsequent draw calls.
 		/// </summary>
@@ -400,8 +423,8 @@ namespace MoonWorks.Graphics
 
 			for (var i = 0; i < length; i += 1)
 			{
-				texturePtrs[i] = textureSamplerBindings[i].Texture.Handle;
+				texturePtrs[i] = textureSamplerBindings[i].TextureHandle;
-				samplerPtrs[i] = textureSamplerBindings[i].Sampler.Handle;
+				samplerPtrs[i] = textureSamplerBindings[i].SamplerHandle;
 			}
 
 			Refresh.Refresh_BindVertexSamplers(
@@ -438,8 +461,19 @@ namespace MoonWorks.Graphics
 
 			for (var i = 0; i < length; i += 1)
 			{
-				texturePtrs[i] = textureSamplerBindings[i].Texture.Handle;
+				#if DEBUG
-				samplerPtrs[i] = textureSamplerBindings[i].Sampler.Handle;
+				if (textureSamplerBindings[i].TextureHandle == IntPtr.Zero)
+				{
+					throw new NullReferenceException("Texture binding must not be null!");
+				}
+				if (textureSamplerBindings[i].TextureHandle == IntPtr.Zero)
+				{
+					throw new NullReferenceException("Sampler binding must not be null!");
+				}
+				#endif
+
+				texturePtrs[i] = textureSamplerBindings[i].TextureHandle;
+				samplerPtrs[i] = textureSamplerBindings[i].SamplerHandle;
 			}
 
 			Refresh.Refresh_BindFragmentSamplers(
@@ -475,7 +509,7 @@ namespace MoonWorks.Graphics
 					Device.Handle,
 					Handle,
 					(IntPtr) ptr,
-					(uint) (uniforms.Length * Marshal.SizeOf<T>())
+					(uint) (uniforms.Length * sizeof(T))
 				);
 			}
 		}
@@ -494,7 +528,7 @@ namespace MoonWorks.Graphics
 					Device.Handle,
 					Handle,
 					(IntPtr) ptr,
-					(uint) (uniforms.Length * Marshal.SizeOf<T>())
+					(uint) (uniforms.Length * sizeof(T))
 				);
 			}
 		}
@@ -513,49 +547,11 @@ namespace MoonWorks.Graphics
 					Device.Handle,
 					Handle,
 					(IntPtr) ptr,
-					(uint) (uniforms.Length * Marshal.SizeOf<T>())
+					(uint) (uniforms.Length * sizeof(T))
 				);
 			}
 		}
 
-		/// <summary>
-		/// Clears the render targets on the current framebuffer to a single color or depth/stencil value.
-		/// NOTE: It is recommended that you clear when beginning render passes unless you have a good reason to clear mid-pass.
-		/// </summary>
-		/// <param name="clearRect">The area of the framebuffer to clear.</param>
-		/// <param name="clearOptions">Whether to clear colors, depth, or stencil value, or multiple.</param>
-		/// <param name="depthStencilClearValue">The depth/stencil clear values. Will be ignored if color is not provided in ClearOptions.</param>
-		/// <param name="clearColors">The color clear values. Must provide one per render target. Can be omitted if depth/stencil is not cleared.</param>
-		public unsafe void Clear(
-			in Rect clearRect,
-			ClearOptionsFlags clearOptions,
-			in DepthStencilValue depthStencilClearValue,
-			params Vector4[] clearColors
-		)
-		{
-			Refresh.Vec4* colors = stackalloc Refresh.Vec4[clearColors.Length];
-			for (var i = 0; i < clearColors.Length; i++)
-			{
-				colors[i] = new Refresh.Vec4
-				{
-					x = clearColors[i].X,
-					y = clearColors[i].Y,
-					z = clearColors[i].Z,
-					w = clearColors[i].W
-				};
-			}
-
-			Refresh.Refresh_Clear(
-				Device.Handle,
-				Handle,
-				clearRect.ToRefresh(),
-				(Refresh.ClearOptionsFlags) clearOptions,
-				(IntPtr) colors,
-				(uint) clearColors.Length,
-				depthStencilClearValue.ToRefresh()
-			);
-		}
-
 		/// <summary>
 		/// Draws using instanced rendering.
 		/// It is an error to call this method unless two vertex buffers have been bound.
@@ -651,126 +647,35 @@ namespace MoonWorks.Graphics
 		}
 
 		/// <summary>
-		/// Prepares a texture to be presented to a window.
+		/// Acquires a swapchain texture.
-		/// This particular variant of this method will present to the entire window area.
+		/// This texture will be presented to the given window when the command buffer is submitted.
+		/// Can return null if the swapchain is unavailable. The user should ALWAYS handle the case where this occurs.
+		/// If null is returned, presentation will not occur.
+		/// It is an error to acquire two swapchain textures from the same window in one command buffer.
 		/// </summary>
-		/// <param name="texture">The texture to present.</param>
+		public Texture? AcquireSwapchainTexture(
-		/// <param name="filter">The filter to use when the texture size differs from the window size.</param>
+			Window window
-		public void QueuePresent(
-			Texture texture,
-			Filter filter,
-			OSWindow window
 		)
 		{
-			var refreshTextureSlice = new Refresh.TextureSlice
+			var texturePtr = Refresh.Refresh_AcquireSwapchainTexture(
+				Device.Handle,
+				Handle,
+				window.Handle,
+				out var width,
+				out var height
+			);
+
+			if (texturePtr == IntPtr.Zero)
 			{
-				texture = texture.Handle,
+				return null;
-				rectangle = new Refresh.Rect
+			}
-				{
-					x = 0,
-					y = 0,
-					w = (int) texture.Width,
-					h = (int) texture.Height
-				},
-				layer = 0,
-				level = 0,
-				depth = 0
-			};
 
-			Refresh.Refresh_QueuePresent(
+			return new Texture(
-				Device.Handle,
+				Device,
-				Handle,
+				texturePtr,
-				refreshTextureSlice,
+				Device.GetSwapchainFormat(window),
-				IntPtr.Zero,
+				width,
-				(Refresh.Filter) filter,
+				height
-				window.Handle
-			);
-		}
-
-		/// <summary>
-		/// Prepares a texture slice to be presented to a window.
-		/// This particular variant of this method will present to the entire window area.
-		/// </summary>
-		/// <param name="textureSlice">The texture slice to present.</param>
-		/// <param name="filter">The filter to use when the texture size differs from the window size.</param>
-		public void QueuePresent(
-			in TextureSlice textureSlice,
-			Filter filter,
-			OSWindow window
-		)
-		{
-			Refresh.Refresh_QueuePresent(
-				Device.Handle,
-				Handle,
-				textureSlice.ToRefreshTextureSlice(),
-				IntPtr.Zero,
-				(Refresh.Filter) filter,
-				window.Handle
-			);
-		}
-
-		/// <summary>
-		/// Prepares a texture to be presented to a window.
-		/// </summary>
-		/// <param name="texture">The texture to present.</param>
-		/// <param name="destinationRectangle">The area of the window to present to.</param>
-		/// <param name="filter">The filter to use when the texture size differs from the destination rectangle.</param>
-		public void QueuePresent(
-			in Texture texture,
-			in Rect destinationRectangle,
-			Filter filter,
-			OSWindow window
-		)
-		{
-			var refreshRect = destinationRectangle.ToRefresh();
-			var refreshTextureSlice = new Refresh.TextureSlice
-			{
-				texture = texture.Handle,
-				rectangle = new Refresh.Rect
-				{
-					x = 0,
-					y = 0,
-					w = (int) texture.Width,
-					h = (int) texture.Height
-				},
-				layer = 0,
-				level = 0,
-				depth = 0
-			};
-
-			Refresh.Refresh_QueuePresent(
-				Device.Handle,
-				Handle,
-				refreshTextureSlice,
-				refreshRect,
-				(Refresh.Filter) filter,
-				window.Handle
-			);
-		}
-
-		/// <summary>
-		/// Prepares a texture slice to be presented to a window.
-		/// </summary>
-		/// <param name="textureSlice">The texture slice to present.</param>
-		/// <param name="destinationRectangle">The area of the window to present to.</param>
-		/// <param name="filter">The filter to use when the texture size differs from the destination rectangle.</param>
-		public void QueuePresent(
-			in TextureSlice textureSlice,
-			in Rect destinationRectangle,
-			Filter filter,
-			OSWindow window
-		)
-		{
-			var refreshTextureSlice = textureSlice.ToRefreshTextureSlice();
-			var refreshRect = destinationRectangle.ToRefresh();
-
-			Refresh.Refresh_QueuePresent(
-				Device.Handle,
-				Handle,
-				refreshTextureSlice,
-				refreshRect,
-				(Refresh.Filter) filter,
-				window.Handle
 			);
 		}
 
@@ -838,7 +743,7 @@ namespace MoonWorks.Graphics
 			uint numElements
 		) where T : unmanaged
 		{
-			var elementSize = Marshal.SizeOf<T>();
+			var elementSize = sizeof(T);
 
 			fixed (T* ptr = &data[0])
 			{
@@ -855,6 +760,22 @@ namespace MoonWorks.Graphics
 			}
 		}
 
+		public unsafe void SetBufferData<T>(
+			Buffer buffer,
+			IntPtr dataPtr,
+			uint bufferOffsetInElements,
+			uint numElements
+		) where T : unmanaged {
+			Refresh.Refresh_SetBufferData(
+				Device.Handle,
+				Handle,
+				buffer.Handle,
+				(uint) sizeof(T) * bufferOffsetInElements,
+				dataPtr,
+				(uint) sizeof(T) * numElements
+			);
+		}
+
 		/// <summary>
 		/// Asynchronously copies data into a texture.
 		/// </summary>
@@ -871,7 +792,7 @@ namespace MoonWorks.Graphics
 		/// <param name="data">An array of data to copy into the texture.</param>
 		public unsafe void SetTextureData<T>(in TextureSlice textureSlice, T[] data) where T : unmanaged
 		{
-			var size = Marshal.SizeOf<T>();
+			var size = sizeof(T);
 
 			fixed (T* ptr = &data[0])
 			{
@@ -912,6 +833,26 @@ namespace MoonWorks.Graphics
 			SetTextureData(new TextureSlice(texture), dataPtr, dataLengthInBytes);
 		}
 
+		/// <summary>
+		/// Asynchronously copies YUV data into three textures. Use with compressed video.
+		/// </summary>
+		public void SetTextureDataYUV(Texture yTexture, Texture uTexture, Texture vTexture, IntPtr dataPtr, uint dataLengthInBytes)
+		{
+			Refresh.Refresh_SetTextureDataYUV(
+				Device.Handle,
+				Handle,
+				yTexture.Handle,
+				uTexture.Handle,
+				vTexture.Handle,
+				yTexture.Width,
+				yTexture.Height,
+				uTexture.Width,
+				uTexture.Height,
+				dataPtr,
+				dataLengthInBytes
+			);
+		}
+
 		/// <summary>
 		/// Performs an asynchronous texture-to-texture copy on the GPU.
 		/// </summary>

src/Graphics/Font/Enums.cs

@@ -0,0 +1,17 @@
+namespace MoonWorks.Graphics.Font
+{
+    public enum HorizontalAlignment
+    {
+        Left,
+        Center,
+        Right
+    }
+
+    public enum VerticalAlignment
+    {
+        Baseline,
+        Top,
+        Middle,
+        Bottom
+    }
+}

src/Graphics/Font/Font.cs

@@ -0,0 +1,44 @@
+using System;
+using System.IO;
+using WellspringCS;
+
+namespace MoonWorks.Graphics.Font
+{
+    public class Font : IDisposable
+    {
+		public IntPtr Handle { get; }
+
+		private bool IsDisposed;
+
+        public unsafe Font(string path)
+        {
+            var bytes = File.ReadAllBytes(path);
+			fixed (byte* pByte = &bytes[0])
+			{
+				Handle = Wellspring.Wellspring_CreateFont((IntPtr) pByte, (uint) bytes.Length);
+			}
+        }
+
+		protected virtual void Dispose(bool disposing)
+		{
+			if (!IsDisposed)
+			{
+				Wellspring.Wellspring_DestroyFont(Handle);
+				IsDisposed = true;
+			}
+		}
+
+		~Font()
+		{
+		    // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+		    Dispose(disposing: false);
+		}
+
+		public void Dispose()
+		{
+			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+			Dispose(disposing: true);
+			GC.SuppressFinalize(this);
+		}
+	}
+}

src/Graphics/Font/Packer.cs

@@ -0,0 +1,109 @@
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using WellspringCS;
+
+namespace MoonWorks.Graphics.Font
+{
+	public class Packer : IDisposable
+	{
+		public IntPtr Handle { get; }
+		public Texture Texture { get; }
+
+		public Font Font { get; }
+
+		private byte[] StringBytes;
+
+		private bool IsDisposed;
+
+		public unsafe Packer(GraphicsDevice graphicsDevice, Font font, float fontSize, uint textureWidth, uint textureHeight, uint padding = 1)
+		{
+			Font = font;
+			Handle = Wellspring.Wellspring_CreatePacker(Font.Handle, fontSize, textureWidth, textureHeight, 0, padding);
+			Texture = Texture.CreateTexture2D(graphicsDevice, textureWidth, textureHeight, TextureFormat.R8, TextureUsageFlags.Sampler);
+			StringBytes = new byte[128];
+		}
+
+		public unsafe bool PackFontRanges(params FontRange[] fontRanges)
+		{
+			fixed (FontRange *pFontRanges = &fontRanges[0])
+			{
+				var nativeSize = fontRanges.Length * sizeof(Wellspring.FontRange);
+				void* fontRangeMemory = NativeMemory.Alloc((nuint) fontRanges.Length, (nuint) sizeof(Wellspring.FontRange));
+				System.Buffer.MemoryCopy(pFontRanges, fontRangeMemory, nativeSize, nativeSize);
+
+				var result = Wellspring.Wellspring_PackFontRanges(Handle, (IntPtr) fontRangeMemory, (uint) fontRanges.Length);
+
+				NativeMemory.Free(fontRangeMemory);
+
+				return result > 0;
+			}
+		}
+
+		public unsafe void SetTextureData(CommandBuffer commandBuffer)
+		{
+			var pixelDataPointer = Wellspring.Wellspring_GetPixelDataPointer(Handle);
+			commandBuffer.SetTextureData(Texture, pixelDataPointer, Texture.Width * Texture.Height);
+		}
+
+		public unsafe void TextBounds(
+			string text,
+			float x,
+			float y,
+			HorizontalAlignment horizontalAlignment,
+			VerticalAlignment verticalAlignment,
+			out Wellspring.Rectangle rectangle
+		) {
+			var byteCount = System.Text.Encoding.UTF8.GetByteCount(text);
+
+			if (StringBytes.Length < byteCount)
+			{
+				System.Array.Resize(ref StringBytes, byteCount);
+			}
+
+			fixed (char* chars = text)
+			fixed (byte* bytes = StringBytes)
+			{
+				System.Text.Encoding.UTF8.GetBytes(chars, text.Length, bytes, byteCount);
+				Wellspring.Wellspring_TextBounds(
+					Handle,
+					x,
+					y,
+					(Wellspring.HorizontalAlignment) horizontalAlignment,
+					(Wellspring.VerticalAlignment) verticalAlignment,
+					(IntPtr) bytes,
+					(uint) byteCount,
+					out rectangle
+				);
+			}
+		}
+
+		protected virtual void Dispose(bool disposing)
+		{
+			if (!IsDisposed)
+			{
+				if (disposing)
+				{
+					Texture.Dispose();
+				}
+
+				Wellspring.Wellspring_DestroyPacker(Handle);
+
+				IsDisposed = true;
+			}
+		}
+
+		~Packer()
+		{
+		    // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+		    Dispose(disposing: false);
+		}
+
+		public void Dispose()
+		{
+			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+			Dispose(disposing: true);
+			GC.SuppressFinalize(this);
+		}
+	}
+}

src/Graphics/Font/Structs.cs

@@ -0,0 +1,22 @@
+using System.Runtime.InteropServices;
+using MoonWorks.Math.Float;
+
+namespace MoonWorks.Graphics.Font
+{
+	[StructLayout(LayoutKind.Sequential)]
+	public struct FontRange
+	{
+		public uint FirstCodepoint;
+		public uint NumChars;
+		public byte OversampleH;
+		public byte OversampleV;
+	}
+
+	[StructLayout(LayoutKind.Sequential)]
+	public struct Vertex
+	{
+		public Vector3 Position;
+		public Vector2 TexCoord;
+		public Color Color;
+	}
+}

src/Graphics/Font/TextBatch.cs

@@ -0,0 +1,110 @@
+using System;
+using WellspringCS;
+
+namespace MoonWorks.Graphics.Font
+{
+	public class TextBatch
+	{
+		private GraphicsDevice GraphicsDevice { get; }
+		public IntPtr Handle { get; }
+
+		public Buffer VertexBuffer { get; protected set; } = null;
+		public Buffer IndexBuffer { get; protected set; } = null;
+		public Texture Texture { get; protected set; }
+		public uint PrimitiveCount { get; protected set; }
+
+		private byte[] StringBytes;
+
+		public TextBatch(GraphicsDevice graphicsDevice)
+		{
+			GraphicsDevice = graphicsDevice;
+			Handle = Wellspring.Wellspring_CreateTextBatch();
+			StringBytes = new byte[128];
+		}
+
+		public void Start(Packer packer)
+		{
+			Wellspring.Wellspring_StartTextBatch(Handle, packer.Handle);
+			Texture = packer.Texture;
+			PrimitiveCount = 0;
+		}
+
+		public unsafe void Draw(
+			string text,
+			float x,
+			float y,
+			float depth,
+			Color color,
+			HorizontalAlignment horizontalAlignment = HorizontalAlignment.Left,
+			VerticalAlignment verticalAlignment = VerticalAlignment.Baseline
+		) {
+			var byteCount = System.Text.Encoding.UTF8.GetByteCount(text);
+
+			if (StringBytes.Length < byteCount)
+			{
+				System.Array.Resize(ref StringBytes, byteCount);
+			}
+
+			fixed (char* chars = text)
+			fixed (byte* bytes = StringBytes)
+			{
+				System.Text.Encoding.UTF8.GetBytes(chars, text.Length, bytes, byteCount);
+
+				var result = Wellspring.Wellspring_Draw(
+					Handle,
+					x,
+					y,
+					depth,
+					new Wellspring.Color { R = color.R, G = color.G, B = color.B, A = color.A },
+					(Wellspring.HorizontalAlignment) horizontalAlignment,
+					(Wellspring.VerticalAlignment) verticalAlignment,
+					(IntPtr) bytes,
+					(uint) byteCount
+				);
+
+				if (result == 0)
+				{
+					throw new System.ArgumentException("Could not decode string!");
+				}
+			}
+		}
+
+		// Call this after you have made all the Draw calls you want.
+		public unsafe void UploadBufferData(CommandBuffer commandBuffer)
+		{
+			Wellspring.Wellspring_GetBufferData(
+				Handle,
+				out uint vertexCount,
+				out IntPtr vertexDataPointer,
+				out uint vertexDataLengthInBytes,
+				out IntPtr indexDataPointer,
+				out uint indexDataLengthInBytes
+			);
+
+			if (VertexBuffer == null)
+			{
+				VertexBuffer = new Buffer(GraphicsDevice, BufferUsageFlags.Vertex, vertexDataLengthInBytes);
+			}
+			else if (VertexBuffer.Size < vertexDataLengthInBytes)
+			{
+				VertexBuffer.Dispose();
+				VertexBuffer = new Buffer(GraphicsDevice, BufferUsageFlags.Vertex, vertexDataLengthInBytes);
+			}
+
+			if (IndexBuffer == null)
+			{
+				IndexBuffer = new Buffer(GraphicsDevice, BufferUsageFlags.Index, indexDataLengthInBytes);
+			}
+			else if (IndexBuffer.Size < indexDataLengthInBytes)
+			{
+				IndexBuffer.Dispose();
+				IndexBuffer = new Buffer(GraphicsDevice, BufferUsageFlags.Index, indexDataLengthInBytes);
+			}
+
+			commandBuffer.SetBufferData(VertexBuffer, vertexDataPointer, 0, vertexDataLengthInBytes);
+			commandBuffer.SetBufferData(IndexBuffer, indexDataPointer, 0, indexDataLengthInBytes);
+
+			PrimitiveCount = vertexCount / 2; // FIXME: is this jank?
+		}
+	}
+}

src/Graphics/GraphicsDevice.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using RefreshCS;
 
 namespace MoonWorks.Graphics
@@ -8,10 +9,14 @@ namespace MoonWorks.Graphics
 	{
 		public IntPtr Handle { get; }
 
+		// Built-in video pipeline
+		private ShaderModule VideoVertexShader { get; }
+		private ShaderModule VideoFragmentShader { get; }
+		internal GraphicsPipeline VideoPipeline { get; }
+
 		public bool IsDisposed { get; private set; }
 
 		private readonly List<WeakReference<GraphicsResource>> resources = new List<WeakReference<GraphicsResource>>();
-		private Dictionary<IntPtr, Action<IntPtr, IntPtr, IntPtr>> resourcesToDestroy = new Dictionary<IntPtr, Action<IntPtr, IntPtr, IntPtr>>();
 
 		public GraphicsDevice(
 			IntPtr deviceWindowHandle,
@@ -29,6 +34,26 @@ namespace MoonWorks.Graphics
 				presentationParameters,
 				Conversions.BoolToByte(debugMode)
 			);
+
+			VideoVertexShader = new ShaderModule(this, GetEmbeddedResource("MoonWorks.Shaders.FullscreenVert.spv"));
+			VideoFragmentShader = new ShaderModule(this, GetEmbeddedResource("MoonWorks.Shaders.YUV2RGBAFrag.spv"));
+
+			VideoPipeline = new GraphicsPipeline(
+				this,
+				new GraphicsPipelineCreateInfo
+				{
+					AttachmentInfo = new GraphicsPipelineAttachmentInfo(
+						new ColorAttachmentDescription(TextureFormat.R8G8B8A8, ColorAttachmentBlendState.None)
+					),
+					DepthStencilState = DepthStencilState.Disable,
+					VertexShaderInfo = GraphicsShaderInfo.Create(VideoVertexShader, "main", 0),
+					FragmentShaderInfo = GraphicsShaderInfo.Create(VideoFragmentShader, "main", 3),
+					VertexInputState = VertexInputState.Empty,
+					RasterizerState = RasterizerState.CCW_CullNone,
+					PrimitiveType = PrimitiveType.TriangleList,
+					MultisampleState = MultisampleState.None
+				}
+			);
 		}
 
 		public CommandBuffer AcquireCommandBuffer()
@@ -57,24 +82,9 @@ namespace MoonWorks.Graphics
 			Refresh.Refresh_Wait(Handle);
 		}
 
-		internal void SubmitDestroyCommandBuffer()
+		public TextureFormat GetSwapchainFormat(Window window)
 		{
-			if (resourcesToDestroy.Count > 0)
+			return (TextureFormat) Refresh.Refresh_GetSwapchainFormat(Handle, window.Handle);
-			{
-				var commandBuffer = AcquireCommandBuffer();
-
-				foreach (var kv in resourcesToDestroy)
-				{
-					kv.Value.Invoke(Handle, commandBuffer.Handle, kv.Key);
-				}
-
-				Submit(commandBuffer);
-			}
-		}
-
-		internal void PrepareDestroyResource(GraphicsResource resource, Action<IntPtr, IntPtr, IntPtr> destroyFunction)
-		{
-			resourcesToDestroy.Add(resource.Handle, destroyFunction);
 		}
 
 		internal void AddResourceReference(WeakReference<GraphicsResource> resourceReference)
@@ -93,6 +103,11 @@ namespace MoonWorks.Graphics
 			}
 		}
 
+		private static Stream GetEmbeddedResource(string name)
+		{
+			return typeof(GraphicsDevice).Assembly.GetManifestResourceStream(name);
+		}
+
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!IsDisposed)
@@ -112,7 +127,6 @@ namespace MoonWorks.Graphics
 						resources.Clear();
 					}
 
-					SubmitDestroyCommandBuffer();
 					Refresh.Refresh_DestroyDevice(Handle);
 				}
 

src/Graphics/GraphicsResource.cs

@@ -8,26 +8,28 @@ namespace MoonWorks.Graphics
 		public IntPtr Handle { get; protected set; }
 
 		public bool IsDisposed { get; private set; }
-		protected abstract Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction { get; }
+		protected abstract Action<IntPtr, IntPtr> QueueDestroyFunction { get; }
 
 		private WeakReference<GraphicsResource> selfReference;
 
-		public GraphicsResource(GraphicsDevice device)
+		public GraphicsResource(GraphicsDevice device, bool trackResource = true)
 		{
 			Device = device;
 
-			selfReference = new WeakReference<GraphicsResource>(this);
+			if (trackResource)
-			Device.AddResourceReference(selfReference);
+			{
+				selfReference = new WeakReference<GraphicsResource>(this);
+				Device.AddResourceReference(selfReference);
+			}
 		}
 
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!IsDisposed)
 			{
-				Device.PrepareDestroyResource(this, QueueDestroyFunction);
-
 				if (selfReference != null)
 				{
+					QueueDestroyFunction(Device.Handle, Handle);
 					Device.RemoveResourceReference(selfReference);
 					selfReference = null;
 				}

src/Graphics/PackedVector/Alpha8.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Bgr565.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Bgra4444.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Bgra5551.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Byte4.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/HalfSingle.cs

@@ -16,7 +16,7 @@
 
 #region Using Statements
 using System;
-using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/HalfVector2.cs

@@ -16,7 +16,7 @@
 
 #region Using Statements
 using System;
-using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/HalfVector4.cs

@@ -16,7 +16,7 @@
 
 #region Using Statements
 using System;
-using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/IPackedVector.cs

@@ -14,7 +14,7 @@
 
 #endregion
 
-using MoonWorks.Math;
+using MoonWorks.Math.Float;
 
 namespace MoonWorks.Graphics
 {

src/Graphics/PackedVector/NormalizedByte2.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/NormalizedByte4.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/NormalizedShort2.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/NormalizedShort4.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Rg32.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Rgba1010102.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Rgba64.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Short2.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/PackedVector/Short4.cs

@@ -17,6 +17,7 @@
 #region Using Statements
 using System;
 using MoonWorks.Math;
+using MoonWorks.Math.Float;
 #endregion
 
 namespace MoonWorks.Graphics

src/Graphics/RefreshEnums.cs

@@ -60,12 +60,14 @@ namespace MoonWorks.Graphics
 	public enum TextureFormat
 	{
 		R8G8B8A8,
+		B8G8R8A8,
 		R5G6B5,
 		A1R5G5B5,
 		B4G4R4A4,
 		BC1,
 		BC2,
 		BC3,
+		BC7,
 		R8G8_SNORM,
 		R8G8B8A8_SNORM,
 		A2R10G10B10,
@@ -123,7 +125,8 @@ namespace MoonWorks.Graphics
 
 	public enum VertexElementFormat
 	{
-		Single,
+		UInt,
+		Float,
 		Vector2,
 		Vector3,
 		Vector4,
@@ -146,16 +149,14 @@ namespace MoonWorks.Graphics
 	public enum FillMode
 	{
 		Fill,
-		Line,
+		Line
-		Point
 	}
 
 	public enum CullMode
 	{
 		None,
 		Front,
-		Back,
+		Back
-		FrontAndBack
 	}
 
 	public enum FrontFace
@@ -197,26 +198,6 @@ namespace MoonWorks.Graphics
 		Max
 	}
 
-	public enum LogicOp
-	{
-		Clear,
-		And,
-		AndReverse,
-		Copy,
-		AndInverted,
-		NoOp,
-		Xor,
-		Or,
-		Nor,
-		Equivalent,
-		Invert,
-		OrReverse,
-		CopyInverted,
-		OrInverted,
-		Nand,
-		Set
-	}
-
 	public enum BlendFactor
 	{
 		Zero,
@@ -231,8 +212,6 @@ namespace MoonWorks.Graphics
 		OneMinusDestinationAlpha,
 		ConstantColor,
 		OneMinusConstantColor,
-		ConstantAlpha,
-		OneMinusConstantAlpha,
 		SourceAlphaSaturate,
 		SourceOneColor,
 		OneMinusSourceOneColor,
@@ -263,17 +242,10 @@ namespace MoonWorks.Graphics
 		None = 0
 	}
 
-	public enum ShaderStageType
-	{
-		Vertex,
-		Fragment
-	}
-
 	public enum Filter
 	{
 		Nearest,
-		Linear,
+		Linear
-		Cubic
 	}
 
 	public enum SamplerMipmapMode

src/Graphics/RefreshStructs.cs

@@ -12,6 +12,12 @@ namespace MoonWorks.Graphics
 		public float Depth;
 		public uint Stencil;
 
+		public DepthStencilValue(float depth, uint stencil)
+		{
+			Depth = depth;
+			Stencil = stencil;
+		}
+
 		// FIXME: can we do an unsafe cast somehow?
 		public Refresh.DepthStencilValue ToRefresh()
 		{
@@ -31,6 +37,22 @@ namespace MoonWorks.Graphics
 		public int W;
 		public int H;
 
+		public Rect(int x, int y, int w, int h)
+		{
+			X = x;
+			Y = y;
+			W = w;
+			H = h;
+		}
+
+		public Rect(int w, int h)
+		{
+			X = 0;
+			Y = 0;
+			W = w;
+			H = h;
+		}
+
 		// FIXME: can we do an unsafe cast somehow?
 		public Refresh.Rect ToRefresh()
 		{
@@ -53,6 +75,49 @@ namespace MoonWorks.Graphics
 		public float H;
 		public float MinDepth;
 		public float MaxDepth;
+
+		public Viewport(float w, float h)
+		{
+			X = 0;
+			Y = 0;
+			W = w;
+			H = h;
+			MinDepth = 0;
+			MaxDepth = 1;
+		}
+
+		public Viewport(float x, float y, float w, float h)
+		{
+			X = x;
+			Y = y;
+			W = w;
+			H = h;
+			MinDepth = 0;
+			MaxDepth = 1;
+		}
+
+		public Viewport(float x, float y, float w, float h, float minDepth, float maxDepth)
+		{
+			X = x;
+			Y = y;
+			W = w;
+			H = h;
+			MinDepth = minDepth;
+			MaxDepth = maxDepth;
+		}
+
+		public Refresh.Viewport ToRefresh()
+		{
+			return new Refresh.Viewport
+			{
+				x = X,
+				y = Y,
+				w = W,
+				h = H,
+				minDepth = MinDepth,
+				maxDepth = MaxDepth
+			};
+		}
 	}
 
 	[StructLayout(LayoutKind.Sequential)]
@@ -61,6 +126,17 @@ namespace MoonWorks.Graphics
 		public uint Binding;
 		public uint Stride;
 		public VertexInputRate InputRate;
+
+		// Shortcut for the common case of having a single vertex binding.
+		public unsafe static VertexBinding Create<T>() where T : unmanaged
+		{
+			return new VertexBinding
+			{
+				Binding = 0,
+				InputRate = VertexInputRate.Vertex,
+				Stride = (uint) sizeof(T)
+			};
+		}
 	}
 
 	[StructLayout(LayoutKind.Sequential)]
@@ -70,6 +146,28 @@ namespace MoonWorks.Graphics
 		public uint Binding;
 		public VertexElementFormat Format;
 		public uint Offset;
+
+		public static VertexAttribute Create<T>(
+			string fieldName,
+			uint location,
+			uint binding = 0
+		)
+		{
+			var fieldInfo = typeof(T).GetField(fieldName);
+
+			if (fieldInfo == null)
+			{
+				throw new System.ArgumentException("Field not recognized!");
+			}
+
+			return new VertexAttribute
+			{
+				Binding = binding,
+				Location = location,
+				Format = Conversions.TypeToVertexElementFormat(fieldInfo.FieldType),
+				Offset = (uint) Marshal.OffsetOf<T>(fieldName)
+			};
+		}
 	}
 
 	[StructLayout(LayoutKind.Sequential)]
@@ -102,25 +200,57 @@ namespace MoonWorks.Graphics
 	[StructLayout(LayoutKind.Sequential)]
 	public struct ColorAttachmentInfo
 	{
-		public RenderTarget renderTarget;
+		public Texture Texture;
-		public Color clearColor;
+		public uint Depth;
-		public LoadOp loadOp;
+		public uint Layer;
-		public StoreOp storeOp;
+		public uint Level;
+		public SampleCount SampleCount;
+		public Color ClearColor;
+		public LoadOp LoadOp;
+		public StoreOp StoreOp;
+
+		public ColorAttachmentInfo(Texture texture, Color clearColor, StoreOp storeOp = StoreOp.Store)
+		{
+			Texture = texture;
+			Depth = 0;
+			Layer = 0;
+			Level = 0;
+			SampleCount = SampleCount.One;
+			ClearColor = clearColor;
+			LoadOp = LoadOp.Clear;
+			StoreOp = storeOp;
+		}
+
+		public ColorAttachmentInfo(Texture texture, LoadOp loadOp = LoadOp.DontCare, StoreOp storeOp = StoreOp.Store)
+		{
+			Texture = texture;
+			Depth = 0;
+			Layer = 0;
+			Level = 0;
+			SampleCount = SampleCount.One;
+			ClearColor = Color.White;
+			LoadOp = loadOp;
+			StoreOp = storeOp;
+		}
 
 		public Refresh.ColorAttachmentInfo ToRefresh()
 		{
 			return new Refresh.ColorAttachmentInfo
 			{
-				renderTarget = renderTarget.Handle,
+				texture = Texture.Handle,
+				depth = Depth,
+				layer = Layer,
+				level = Level,
+				sampleCount = (Refresh.SampleCount) SampleCount,
 				clearColor = new Refresh.Vec4
 				{
-					x = clearColor.R / 255f,
+					x = ClearColor.R / 255f,
-					y = clearColor.G / 255f,
+					y = ClearColor.G / 255f,
-					z = clearColor.B / 255f,
+					z = ClearColor.B / 255f,
-					w = clearColor.A / 255f
+					w = ClearColor.A / 255f
 				},
-				loadOp = (Refresh.LoadOp) loadOp,
+				loadOp = (Refresh.LoadOp) LoadOp,
-				storeOp = (Refresh.StoreOp) storeOp
+				storeOp = (Refresh.StoreOp) StoreOp
 			};
 		}
 	}
@@ -128,23 +258,65 @@ namespace MoonWorks.Graphics
 	[StructLayout(LayoutKind.Sequential)]
 	public struct DepthStencilAttachmentInfo
 	{
-		public RenderTarget depthStencilTarget;
+		public Texture Texture;
-		public DepthStencilValue depthStencilValue;
+		public uint Depth;
-		public LoadOp loadOp;
+		public uint Layer;
-		public StoreOp storeOp;
+		public uint Level;
-		public LoadOp stencilLoadOp;
+		public DepthStencilValue DepthStencilClearValue;
-		public StoreOp stencilStoreOp;
+		public LoadOp LoadOp;
+		public StoreOp StoreOp;
+		public LoadOp StencilLoadOp;
+		public StoreOp StencilStoreOp;
+
+		public DepthStencilAttachmentInfo(
+			Texture texture,
+			DepthStencilValue clearValue,
+			StoreOp depthStoreOp = StoreOp.Store,
+			StoreOp stencilStoreOp = StoreOp.Store
+		)
+		{
+			Texture = texture;
+			Depth = 0;
+			Layer = 0;
+			Level = 0;
+			DepthStencilClearValue = clearValue;
+			LoadOp = LoadOp.Clear;
+			StoreOp = depthStoreOp;
+			StencilLoadOp = LoadOp.Clear;
+			StencilStoreOp = stencilStoreOp;
+		}
+
+		public DepthStencilAttachmentInfo(
+			Texture texture,
+			LoadOp loadOp = LoadOp.DontCare,
+			StoreOp storeOp = StoreOp.Store,
+			LoadOp stencilLoadOp = LoadOp.DontCare,
+			StoreOp stencilStoreOp = StoreOp.Store
+		) {
+			Texture = texture;
+			Depth = 0;
+			Layer = 0;
+			Level = 0;
+			DepthStencilClearValue = new DepthStencilValue();
+			LoadOp = loadOp;
+			StoreOp = storeOp;
+			StencilLoadOp = stencilLoadOp;
+			StencilStoreOp = stencilStoreOp;
+		}
 
 		public Refresh.DepthStencilAttachmentInfo ToRefresh()
 		{
 			return new Refresh.DepthStencilAttachmentInfo
 			{
-				depthStencilTarget = depthStencilTarget.Handle,
+				texture = Texture.Handle,
-				depthStencilValue = depthStencilValue.ToRefresh(),
+				depth = Depth,
-				loadOp = (Refresh.LoadOp) loadOp,
+				layer = Layer,
-				storeOp = (Refresh.StoreOp) storeOp,
+				level = Level,
-				stencilLoadOp = (Refresh.LoadOp) stencilLoadOp,
+				depthStencilClearValue = DepthStencilClearValue.ToRefresh(),
-				stencilStoreOp = (Refresh.StoreOp) stencilStoreOp
+				loadOp = (Refresh.LoadOp) LoadOp,
+				storeOp = (Refresh.StoreOp) StoreOp,
+				stencilLoadOp = (Refresh.LoadOp) StencilLoadOp,
+				stencilStoreOp = (Refresh.StoreOp) StencilStoreOp
 			};
 		}
 	}
@@ -152,7 +324,18 @@ namespace MoonWorks.Graphics
 	[StructLayout(LayoutKind.Sequential)]
 	public struct ColorAttachmentDescription
 	{
-		public TextureFormat format;
+		public TextureFormat Format;
-		public SampleCount sampleCount;
+		public SampleCount SampleCount;
+		public ColorAttachmentBlendState BlendState;
+
+		public ColorAttachmentDescription(
+			TextureFormat format,
+			ColorAttachmentBlendState blendState,
+			SampleCount sampleCount = SampleCount.One
+		) {
+			Format = format;
+			SampleCount = sampleCount;
+			BlendState = blendState;
+		}
 	}
 }

src/Graphics/Resources/Buffer.cs

@@ -9,7 +9,33 @@ namespace MoonWorks.Graphics
 	/// </summary>
 	public class Buffer : GraphicsResource
 	{
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyBuffer;
+		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyBuffer;
+
+		/// <summary>
+		/// Size in bytes.
+		/// </summary>
+		public uint Size { get; }
+
+		/// <summary>
+		/// Creates a buffer of appropriate size given a type and element count.
+		/// </summary>
+		/// <typeparam name="T">The type that the buffer will contain.</typeparam>
+		/// <param name="device">The GraphicsDevice.</param>
+		/// <param name="usageFlags">Specifies how the buffer will be used.</param>
+		/// <param name="elementCount">How many elements of type T the buffer will contain.</param>
+		/// <returns></returns>
+		public unsafe static Buffer Create<T>(
+			GraphicsDevice device,
+			BufferUsageFlags usageFlags,
+			uint elementCount
+		) where T : unmanaged
+		{
+			return new Buffer(
+				device,
+				usageFlags,
+				(uint) sizeof(T) * elementCount
+			);
+		}
 
 		/// <summary>
 		/// Creates a buffer.
@@ -28,6 +54,7 @@ namespace MoonWorks.Graphics
 				(Refresh.BufferUsageFlags) usageFlags,
 				sizeInBytes
 			);
+			Size = sizeInBytes;
 		}
 
 		/// <summary>

src/Graphics/Resources/ComputePipeline.cs

@@ -6,40 +6,30 @@ namespace MoonWorks.Graphics
 {
 	public class ComputePipeline : GraphicsResource
 	{
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyComputePipeline;
+		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyComputePipeline;
 
-		public ShaderStageState ComputeShaderState { get; }
+		public ComputeShaderInfo ComputeShaderInfo { get; }
 
 		public unsafe ComputePipeline(
 			GraphicsDevice device,
-			ShaderStageState computeShaderState,
+			ComputeShaderInfo computeShaderInfo
-			uint bufferBindingCount,
-			uint imageBindingCount
 		) : base(device)
 		{
-			var computePipelineLayoutCreateInfo = new Refresh.ComputePipelineLayoutCreateInfo
+			var refreshComputeShaderInfo = new Refresh.ComputeShaderInfo
 			{
-				bufferBindingCount = bufferBindingCount,
+				entryPointName = computeShaderInfo.EntryPointName,
-				imageBindingCount = imageBindingCount
+				shaderModule = computeShaderInfo.ShaderModule.Handle,
-			};
+				uniformBufferSize = computeShaderInfo.UniformBufferSize,
-
+				bufferBindingCount = computeShaderInfo.BufferBindingCount,
-			var computePipelineCreateInfo = new Refresh.ComputePipelineCreateInfo
+				imageBindingCount = computeShaderInfo.ImageBindingCount
-			{
-				pipelineLayoutCreateInfo = computePipelineLayoutCreateInfo,
-				computeShaderState = new Refresh.ShaderStageState
-				{
-					entryPointName = computeShaderState.EntryPointName,
-					shaderModule = computeShaderState.ShaderModule.Handle,
-					uniformBufferSize = computeShaderState.UniformBufferSize
-				}
 			};
 
 			Handle = Refresh.Refresh_CreateComputePipeline(
 				device.Handle,
-				computePipelineCreateInfo
+				refreshComputeShaderInfo
 			);
 
-			ComputeShaderState = computeShaderState;
+			ComputeShaderInfo = computeShaderInfo;
 		}
 	}
 }

src/Graphics/Resources/GraphicsPipeline.cs

@@ -10,27 +10,25 @@ namespace MoonWorks.Graphics
 	/// </summary>
 	public class GraphicsPipeline : GraphicsResource
 	{
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyGraphicsPipeline;
+		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyGraphicsPipeline;
 
-		public ShaderStageState VertexShaderState { get; }
+		public GraphicsShaderInfo VertexShaderInfo { get; }
-		public ShaderStageState FragmentShaderState { get; }
+		public GraphicsShaderInfo FragmentShaderInfo { get; }
 
 		public unsafe GraphicsPipeline(
 			GraphicsDevice device,
 			in GraphicsPipelineCreateInfo graphicsPipelineCreateInfo
 		) : base(device)
 		{
-			ColorBlendState colorBlendState = graphicsPipelineCreateInfo.ColorBlendState;
 			DepthStencilState depthStencilState = graphicsPipelineCreateInfo.DepthStencilState;
-			ShaderStageState vertexShaderState = graphicsPipelineCreateInfo.VertexShaderState;
+			GraphicsShaderInfo vertexShaderInfo = graphicsPipelineCreateInfo.VertexShaderInfo;
-			ShaderStageState fragmentShaderState = graphicsPipelineCreateInfo.FragmentShaderState;
+			GraphicsShaderInfo fragmentShaderInfo = graphicsPipelineCreateInfo.FragmentShaderInfo;
 			MultisampleState multisampleState = graphicsPipelineCreateInfo.MultisampleState;
-			GraphicsPipelineLayoutInfo pipelineLayoutInfo = graphicsPipelineCreateInfo.PipelineLayoutInfo;
 			RasterizerState rasterizerState = graphicsPipelineCreateInfo.RasterizerState;
 			PrimitiveType primitiveType = graphicsPipelineCreateInfo.PrimitiveType;
 			VertexInputState vertexInputState = graphicsPipelineCreateInfo.VertexInputState;
-			ViewportState viewportState = graphicsPipelineCreateInfo.ViewportState;
 			GraphicsPipelineAttachmentInfo attachmentInfo = graphicsPipelineCreateInfo.AttachmentInfo;
+			BlendConstants blendConstants = graphicsPipelineCreateInfo.BlendConstants;
 
 			var vertexAttributesHandle = GCHandle.Alloc(
 				vertexInputState.VertexAttributes,
@@ -40,44 +38,24 @@ namespace MoonWorks.Graphics
 				vertexInputState.VertexBindings,
 				GCHandleType.Pinned
 			);
-			var viewportHandle = GCHandle.Alloc(
-				viewportState.Viewports,
-				GCHandleType.Pinned
-			);
-			var scissorHandle = GCHandle.Alloc(
-				viewportState.Scissors,
-				GCHandleType.Pinned
-			);
-
-			var colorTargetBlendStates = stackalloc Refresh.ColorTargetBlendState[
-				colorBlendState.ColorTargetBlendStates.Length
-			];
-
-			for (var i = 0; i < colorBlendState.ColorTargetBlendStates.Length; i += 1)
-			{
-				colorTargetBlendStates[i] = colorBlendState.ColorTargetBlendStates[i].ToRefreshColorTargetBlendState();
-			}
 
 			var colorAttachmentDescriptions = stackalloc Refresh.ColorAttachmentDescription[
-				(int) attachmentInfo.colorAttachmentCount
+				(int) attachmentInfo.ColorAttachmentDescriptions.Length
 			];
 
-			for (var i = 0; i < attachmentInfo.colorAttachmentCount; i += 1)
+			for (var i = 0; i < attachmentInfo.ColorAttachmentDescriptions.Length; i += 1)
 			{
-				colorAttachmentDescriptions[i].format = (Refresh.TextureFormat) attachmentInfo.colorAttachmentDescriptions[i].format;
+				colorAttachmentDescriptions[i].format = (Refresh.TextureFormat) attachmentInfo.ColorAttachmentDescriptions[i].Format;
-				colorAttachmentDescriptions[i].sampleCount = (Refresh.SampleCount) attachmentInfo.colorAttachmentDescriptions[i].sampleCount;
+				colorAttachmentDescriptions[i].sampleCount = (Refresh.SampleCount) attachmentInfo.ColorAttachmentDescriptions[i].SampleCount;
+				colorAttachmentDescriptions[i].blendState = attachmentInfo.ColorAttachmentDescriptions[i].BlendState.ToRefresh();
 			}
 
 			Refresh.GraphicsPipelineCreateInfo refreshGraphicsPipelineCreateInfo;
 
-			refreshGraphicsPipelineCreateInfo.colorBlendState.logicOpEnable = Conversions.BoolToByte(colorBlendState.LogicOpEnable);
+			refreshGraphicsPipelineCreateInfo.blendConstants[0] = blendConstants.R;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.logicOp = (Refresh.LogicOp) colorBlendState.LogicOp;
+			refreshGraphicsPipelineCreateInfo.blendConstants[1] = blendConstants.G;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.blendStates = (IntPtr) colorTargetBlendStates;
+			refreshGraphicsPipelineCreateInfo.blendConstants[2] = blendConstants.B;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.blendStateCount = (uint) colorBlendState.ColorTargetBlendStates.Length;
+			refreshGraphicsPipelineCreateInfo.blendConstants[3] = blendConstants.A;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.blendConstants[0] = colorBlendState.BlendConstants.R;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.blendConstants[1] = colorBlendState.BlendConstants.G;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.blendConstants[2] = colorBlendState.BlendConstants.B;
-			refreshGraphicsPipelineCreateInfo.colorBlendState.blendConstants[3] = colorBlendState.BlendConstants.A;
 
 			refreshGraphicsPipelineCreateInfo.depthStencilState.backStencilState = depthStencilState.BackStencilState.ToRefresh();
 			refreshGraphicsPipelineCreateInfo.depthStencilState.compareOp = (Refresh.CompareOp) depthStencilState.CompareOp;
@@ -89,20 +67,19 @@ namespace MoonWorks.Graphics
 			refreshGraphicsPipelineCreateInfo.depthStencilState.minDepthBounds = depthStencilState.MinDepthBounds;
 			refreshGraphicsPipelineCreateInfo.depthStencilState.stencilTestEnable = Conversions.BoolToByte(depthStencilState.StencilTestEnable);
 
-			refreshGraphicsPipelineCreateInfo.vertexShaderState.entryPointName = vertexShaderState.EntryPointName;
+			refreshGraphicsPipelineCreateInfo.vertexShaderInfo.entryPointName = vertexShaderInfo.EntryPointName;
-			refreshGraphicsPipelineCreateInfo.vertexShaderState.shaderModule = vertexShaderState.ShaderModule.Handle;
+			refreshGraphicsPipelineCreateInfo.vertexShaderInfo.shaderModule = vertexShaderInfo.ShaderModule.Handle;
-			refreshGraphicsPipelineCreateInfo.vertexShaderState.uniformBufferSize = vertexShaderState.UniformBufferSize;
+			refreshGraphicsPipelineCreateInfo.vertexShaderInfo.uniformBufferSize = vertexShaderInfo.UniformBufferSize;
+			refreshGraphicsPipelineCreateInfo.vertexShaderInfo.samplerBindingCount = vertexShaderInfo.SamplerBindingCount;
 
-			refreshGraphicsPipelineCreateInfo.fragmentShaderState.entryPointName = fragmentShaderState.EntryPointName;
+			refreshGraphicsPipelineCreateInfo.fragmentShaderInfo.entryPointName = fragmentShaderInfo.EntryPointName;
-			refreshGraphicsPipelineCreateInfo.fragmentShaderState.shaderModule = fragmentShaderState.ShaderModule.Handle;
+			refreshGraphicsPipelineCreateInfo.fragmentShaderInfo.shaderModule = fragmentShaderInfo.ShaderModule.Handle;
-			refreshGraphicsPipelineCreateInfo.fragmentShaderState.uniformBufferSize = fragmentShaderState.UniformBufferSize;
+			refreshGraphicsPipelineCreateInfo.fragmentShaderInfo.uniformBufferSize = fragmentShaderInfo.UniformBufferSize;
+			refreshGraphicsPipelineCreateInfo.fragmentShaderInfo.samplerBindingCount = fragmentShaderInfo.SamplerBindingCount;
 
 			refreshGraphicsPipelineCreateInfo.multisampleState.multisampleCount = (Refresh.SampleCount) multisampleState.MultisampleCount;
 			refreshGraphicsPipelineCreateInfo.multisampleState.sampleMask = multisampleState.SampleMask;
 
-			refreshGraphicsPipelineCreateInfo.pipelineLayoutCreateInfo.vertexSamplerBindingCount = pipelineLayoutInfo.VertexSamplerBindingCount;
-			refreshGraphicsPipelineCreateInfo.pipelineLayoutCreateInfo.fragmentSamplerBindingCount = pipelineLayoutInfo.FragmentSamplerBindingCount;
-
 			refreshGraphicsPipelineCreateInfo.rasterizerState.cullMode = (Refresh.CullMode) rasterizerState.CullMode;
 			refreshGraphicsPipelineCreateInfo.rasterizerState.depthBiasClamp = rasterizerState.DepthBiasClamp;
 			refreshGraphicsPipelineCreateInfo.rasterizerState.depthBiasConstantFactor = rasterizerState.DepthBiasConstantFactor;
@@ -111,34 +88,26 @@ namespace MoonWorks.Graphics
 			refreshGraphicsPipelineCreateInfo.rasterizerState.depthClampEnable = Conversions.BoolToByte(rasterizerState.DepthClampEnable);
 			refreshGraphicsPipelineCreateInfo.rasterizerState.fillMode = (Refresh.FillMode) rasterizerState.FillMode;
 			refreshGraphicsPipelineCreateInfo.rasterizerState.frontFace = (Refresh.FrontFace) rasterizerState.FrontFace;
-			refreshGraphicsPipelineCreateInfo.rasterizerState.lineWidth = rasterizerState.LineWidth;
 
 			refreshGraphicsPipelineCreateInfo.vertexInputState.vertexAttributes = vertexAttributesHandle.AddrOfPinnedObject();
 			refreshGraphicsPipelineCreateInfo.vertexInputState.vertexAttributeCount = (uint) vertexInputState.VertexAttributes.Length;
 			refreshGraphicsPipelineCreateInfo.vertexInputState.vertexBindings = vertexBindingsHandle.AddrOfPinnedObject();
 			refreshGraphicsPipelineCreateInfo.vertexInputState.vertexBindingCount = (uint) vertexInputState.VertexBindings.Length;
 
-			refreshGraphicsPipelineCreateInfo.viewportState.viewports = viewportHandle.AddrOfPinnedObject();
-			refreshGraphicsPipelineCreateInfo.viewportState.viewportCount = (uint) viewportState.Viewports.Length;
-			refreshGraphicsPipelineCreateInfo.viewportState.scissors = scissorHandle.AddrOfPinnedObject();
-			refreshGraphicsPipelineCreateInfo.viewportState.scissorCount = (uint) viewportState.Scissors.Length;
-
 			refreshGraphicsPipelineCreateInfo.primitiveType = (Refresh.PrimitiveType) primitiveType;
 
-			refreshGraphicsPipelineCreateInfo.attachmentInfo.colorAttachmentCount = attachmentInfo.colorAttachmentCount;
+			refreshGraphicsPipelineCreateInfo.attachmentInfo.colorAttachmentCount = (uint) attachmentInfo.ColorAttachmentDescriptions.Length;
 			refreshGraphicsPipelineCreateInfo.attachmentInfo.colorAttachmentDescriptions = (IntPtr) colorAttachmentDescriptions;
-			refreshGraphicsPipelineCreateInfo.attachmentInfo.depthStencilFormat = (Refresh.TextureFormat) attachmentInfo.depthStencilFormat;
+			refreshGraphicsPipelineCreateInfo.attachmentInfo.depthStencilFormat = (Refresh.TextureFormat) attachmentInfo.DepthStencilFormat;
-			refreshGraphicsPipelineCreateInfo.attachmentInfo.hasDepthStencilAttachment = Conversions.BoolToByte(attachmentInfo.hasDepthStencilAttachment);
+			refreshGraphicsPipelineCreateInfo.attachmentInfo.hasDepthStencilAttachment = Conversions.BoolToByte(attachmentInfo.HasDepthStencilAttachment);
 
 			Handle = Refresh.Refresh_CreateGraphicsPipeline(device.Handle, refreshGraphicsPipelineCreateInfo);
 
 			vertexAttributesHandle.Free();
 			vertexBindingsHandle.Free();
-			viewportHandle.Free();
-			scissorHandle.Free();
 
-			VertexShaderState = vertexShaderState;
+			VertexShaderInfo = vertexShaderInfo;
-			FragmentShaderState = fragmentShaderState;
+			FragmentShaderInfo = fragmentShaderInfo;
 		}
 	}
 }

src/Graphics/Resources/RenderTarget.cs

@@ -1,94 +0,0 @@
-using System;
-using RefreshCS;
-
-namespace MoonWorks.Graphics
-{
-	/// <summary>
-	/// A render target is a structure that wraps a texture so that it can be rendered to.
-	/// </summary>
-	public class RenderTarget : GraphicsResource
-	{
-		public TextureSlice TextureSlice { get; }
-		public TextureFormat Format => TextureSlice.Texture.Format;
-
-		public uint Width => (uint) TextureSlice.Rectangle.W;
-		public uint Height => (uint) TextureSlice.Rectangle.H;
-
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyRenderTarget;
-
-		/// <summary>
-		/// Creates a render target backed by a texture.
-		/// </summary>
-		/// <param name="device">An initialized GraphicsDevice.</param>
-		/// <param name="width">The width of the render target.</param>
-		/// <param name="height">The height of the render target.</param>
-		/// <param name="format">The format of the render target.</param>
-		/// <param name="canBeSampled">Whether the render target can be used by a sampler.</param>
-		/// <param name="sampleCount">The multisample count of the render target.</param>
-		/// <param name="levelCount">The mip level of the render target.</param>
-		/// <returns></returns>
-		public static RenderTarget CreateBackedRenderTarget(
-			GraphicsDevice device,
-			uint width,
-			uint height,
-			TextureFormat format,
-			bool canBeSampled,
-			SampleCount sampleCount = SampleCount.One,
-			uint levelCount = 1
-		)
-		{
-			TextureUsageFlags flags = 0;
-
-			if (
-				format == TextureFormat.D16 ||
-				format == TextureFormat.D32 ||
-				format == TextureFormat.D16S8 ||
-				format == TextureFormat.D32S8
-			)
-			{
-				flags |= TextureUsageFlags.DepthStencilTarget;
-			}
-			else
-			{
-				flags |= TextureUsageFlags.ColorTarget;
-			}
-
-			if (canBeSampled)
-			{
-				flags |= TextureUsageFlags.Sampler;
-			}
-
-			var texture = Texture.CreateTexture2D(
-				device,
-				width,
-				height,
-				format,
-				flags,
-				sampleCount,
-				levelCount
-			);
-
-			return new RenderTarget(device, new TextureSlice(texture), sampleCount);
-		}
-
-		/// <summary>
-		/// Creates a render target using a texture slice and an optional sample count.
-		/// </summary>
-		/// <param name="device">An initialized GraphicsDevice.</param>
-		/// <param name="textureSlice">The texture slice that will be rendered to.</param>
-		/// <param name="sampleCount">The desired multisample count of the render target.</param>
-		public RenderTarget(
-			GraphicsDevice device,
-			in TextureSlice textureSlice,
-			SampleCount sampleCount = SampleCount.One
-		) : base(device)
-		{
-			Handle = Refresh.Refresh_CreateRenderTarget(
-				device.Handle,
-				textureSlice.ToRefreshTextureSlice(),
-				(Refresh.SampleCount) sampleCount
-			);
-			TextureSlice = textureSlice;
-		}
-	}
-}

src/Graphics/Resources/Sampler.cs

@@ -8,7 +8,7 @@ namespace MoonWorks.Graphics
 	/// </summary>
 	public class Sampler : GraphicsResource
 	{
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroySampler;
+		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroySampler;
 
 		public Sampler(
 			GraphicsDevice device,

src/Graphics/Resources/ShaderModule.cs

@@ -1,5 +1,6 @@
 using RefreshCS;
 using System;
+using System.IO;
 
 namespace MoonWorks.Graphics
 {
@@ -8,19 +9,33 @@ namespace MoonWorks.Graphics
 	/// </summary>
 	public class ShaderModule : GraphicsResource
 	{
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyShaderModule;
+		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyShaderModule;
 
 		public unsafe ShaderModule(GraphicsDevice device, string filePath) : base(device)
 		{
-			var bytecode = Bytecode.ReadBytecodeAsUInt32(filePath);
+			using (FileStream stream = new FileStream(filePath, FileMode.Open))
+			{
+				Handle = CreateFromStream(device, stream);
+			}
+		}
 
-			fixed (uint* ptr = bytecode)
+		public unsafe ShaderModule(GraphicsDevice device, Stream stream) : base(device)
+		{
+			Handle = CreateFromStream(device, stream);
+		}
+
+		private unsafe static IntPtr CreateFromStream(GraphicsDevice device, Stream stream)
+		{
+			var bytecode = new byte[stream.Length];
+			stream.Read(bytecode, 0, (int) stream.Length);
+
+			fixed (byte* ptr = bytecode)
 			{
 				Refresh.ShaderModuleCreateInfo shaderModuleCreateInfo;
-				shaderModuleCreateInfo.codeSize = (UIntPtr) (bytecode.Length * sizeof(uint));
+				shaderModuleCreateInfo.codeSize = (UIntPtr) bytecode.Length;
 				shaderModuleCreateInfo.byteCode = (IntPtr) ptr;
 
-				Handle = Refresh.Refresh_CreateShaderModule(device.Handle, shaderModuleCreateInfo);
+				return Refresh.Refresh_CreateShaderModule(device.Handle, shaderModuleCreateInfo);
 			}
 		}
 	}

src/Graphics/Resources/Texture.cs

@@ -1,4 +1,5 @@
 using System;
+using System.IO;
 using RefreshCS;
 
 namespace MoonWorks.Graphics
@@ -17,7 +18,7 @@ namespace MoonWorks.Graphics
 		public SampleCount SampleCount { get; }
 		public TextureUsageFlags UsageFlags { get; }
 
-		protected override Action<IntPtr, IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyTexture;
+		protected override Action<IntPtr, IntPtr> QueueDestroyFunction => Refresh.Refresh_QueueDestroyTexture;
 
 		/// <summary>
 		/// Loads a PNG from a file path.
@@ -56,11 +57,62 @@ namespace MoonWorks.Graphics
 			return texture;
 		}
 
-		public unsafe static void SavePNG(string path, int width, int height, byte[] pixels)
+		/// <summary>
+		/// Saves RGBA or BGRA pixel data to a file in PNG format.
+		/// </summary>
+		public unsafe static void SavePNG(string path, int width, int height, TextureFormat format, byte[] pixels)
 		{
+			if (format != TextureFormat.R8G8B8A8 && format != TextureFormat.B8G8R8A8)
+			{
+				throw new ArgumentException("Texture format must be RGBA8 or BGRA8!", "format");
+			}
+
 			fixed (byte* ptr = &pixels[0])
 			{
-				Refresh.Refresh_Image_SavePNG(path, width, height, (IntPtr) ptr);
+				Refresh.Refresh_Image_SavePNG(path, width, height, Conversions.BoolToByte(format == TextureFormat.B8G8R8A8), (IntPtr) ptr);
+			}
+		}
+
+		public static Texture LoadDDS(GraphicsDevice graphicsDevice, CommandBuffer commandBuffer, System.IO.Stream stream)
+		{
+			using (var reader = new BinaryReader(stream))
+			{
+				Texture texture;
+				int faces;
+				ParseDDS(reader, out var format, out var width, out var height, out var levels, out var isCube);
+
+				if (isCube)
+				{
+					texture = CreateTextureCube(graphicsDevice, (uint) width, format, TextureUsageFlags.Sampler, SampleCount.One, (uint) levels);
+					faces = 6;
+				}
+				else
+				{
+					texture = CreateTexture2D(graphicsDevice, (uint) width, (uint) height, format, TextureUsageFlags.Sampler, SampleCount.One, (uint) levels);
+					faces = 1;
+				}
+
+				for (int i = 0; i < faces; i += 1)
+				{
+					for (int j = 0; j < levels; j += 1)
+					{
+						var levelWidth = width >> j;
+						var levelHeight = height >> j;
+
+						var pixels = reader.ReadBytes(
+							Texture.CalculateDDSLevelSize(
+								levelWidth,
+								levelHeight,
+								format
+							)
+						);
+
+						var textureSlice = new TextureSlice(texture, new Rect(0, 0, levelWidth, levelHeight), 0, (uint) i, (uint) j);
+						commandBuffer.SetTextureData(textureSlice, pixels);
+					}
+				}
+
+				return texture;
 			}
 		}
 
@@ -191,8 +243,301 @@ namespace MoonWorks.Graphics
 			IsCube = textureCreateInfo.IsCube;
 			SampleCount = textureCreateInfo.SampleCount;
 			LevelCount = textureCreateInfo.LevelCount;
-			SampleCount = textureCreateInfo.SampleCount;
 			UsageFlags = textureCreateInfo.UsageFlags;
 		}
+
+		public static implicit operator TextureSlice(Texture t) => new TextureSlice(t);
+
+		// Used by AcquireSwapchainTexture.
+		// Should not be tracked, because swapchain textures are managed by Vulkan.
+		internal Texture(
+			GraphicsDevice device,
+			IntPtr handle,
+			TextureFormat format,
+			uint width,
+			uint height
+		) : base(device, false)
+		{
+			Handle = handle;
+
+			Format = format;
+			Width = width;
+			Height = height;
+			Depth = 1;
+			IsCube = false;
+			SampleCount = SampleCount.One;
+			LevelCount = 1;
+			UsageFlags = TextureUsageFlags.ColorTarget;
+		}
+
+		// DDS loading extension, based on MojoDDS
+		// Taken from https://github.com/FNA-XNA/FNA/blob/1e49f868f595f62bc6385db45949a03186a7cd7f/src/Graphics/Texture.cs#L194
+		private static void ParseDDS(
+			BinaryReader reader,
+			out TextureFormat format,
+			out int width,
+			out int height,
+			out int levels,
+			out bool isCube
+		) {
+			// A whole bunch of magic numbers, yay DDS!
+			const uint DDS_MAGIC = 0x20534444;
+			const uint DDS_HEADERSIZE = 124;
+			const uint DDS_PIXFMTSIZE = 32;
+			const uint DDSD_CAPS = 0x1;
+			const uint DDSD_HEIGHT = 0x2;
+			const uint DDSD_WIDTH = 0x4;
+			const uint DDSD_PITCH = 0x8;
+			const uint DDSD_FMT = 0x1000;
+			const uint DDSD_LINEARSIZE = 0x80000;
+			const uint DDSD_REQ = (
+				DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH | DDSD_FMT
+			);
+			const uint DDSCAPS_MIPMAP = 0x400000;
+			const uint DDSCAPS_TEXTURE = 0x1000;
+			const uint DDSCAPS2_CUBEMAP = 0x200;
+			const uint DDPF_FOURCC = 0x4;
+			const uint DDPF_RGB = 0x40;
+			const uint FOURCC_DXT1 = 0x31545844;
+			const uint FOURCC_DXT3 = 0x33545844;
+			const uint FOURCC_DXT5 = 0x35545844;
+			const uint FOURCC_DX10 = 0x30315844;
+			const uint pitchAndLinear = (
+				DDSD_PITCH | DDSD_LINEARSIZE
+			);
+
+			// File should start with 'DDS '
+			if (reader.ReadUInt32() != DDS_MAGIC)
+			{
+				throw new NotSupportedException("Not a DDS!");
+			}
+
+			// Texture info
+			uint size = reader.ReadUInt32();
+			if (size != DDS_HEADERSIZE)
+			{
+				throw new NotSupportedException("Invalid DDS header!");
+			}
+			uint flags = reader.ReadUInt32();
+			if ((flags & DDSD_REQ) != DDSD_REQ)
+			{
+				throw new NotSupportedException("Invalid DDS flags!");
+			}
+			if ((flags & pitchAndLinear) == pitchAndLinear)
+			{
+				throw new NotSupportedException("Invalid DDS flags!");
+			}
+			height = reader.ReadInt32();
+			width = reader.ReadInt32();
+			reader.ReadUInt32(); // dwPitchOrLinearSize, unused
+			reader.ReadUInt32(); // dwDepth, unused
+			levels = reader.ReadInt32();
+
+			// "Reserved"
+			reader.ReadBytes(4 * 11);
+
+			// Format info
+			uint formatSize = reader.ReadUInt32();
+			if (formatSize != DDS_PIXFMTSIZE)
+			{
+				throw new NotSupportedException("Bogus PIXFMTSIZE!");
+			}
+			uint formatFlags = reader.ReadUInt32();
+			uint formatFourCC = reader.ReadUInt32();
+			uint formatRGBBitCount = reader.ReadUInt32();
+			uint formatRBitMask = reader.ReadUInt32();
+			uint formatGBitMask = reader.ReadUInt32();
+			uint formatBBitMask = reader.ReadUInt32();
+			uint formatABitMask = reader.ReadUInt32();
+
+			// dwCaps "stuff"
+			uint caps = reader.ReadUInt32();
+			if ((caps & DDSCAPS_TEXTURE) == 0)
+			{
+				throw new NotSupportedException("Not a texture!");
+			}
+
+			isCube = false;
+
+			uint caps2 = reader.ReadUInt32();
+			if (caps2 != 0)
+			{
+				if ((caps2 & DDSCAPS2_CUBEMAP) == DDSCAPS2_CUBEMAP)
+				{
+					isCube = true;
+				}
+				else
+				{
+					throw new NotSupportedException("Invalid caps2!");
+				}
+			}
+
+			reader.ReadUInt32(); // dwCaps3, unused
+			reader.ReadUInt32(); // dwCaps4, unused
+
+			// "Reserved"
+			reader.ReadUInt32();
+
+			// Mipmap sanity check
+			if ((caps & DDSCAPS_MIPMAP) != DDSCAPS_MIPMAP)
+			{
+				levels = 1;
+			}
+
+			// Determine texture format
+			if ((formatFlags & DDPF_FOURCC) == DDPF_FOURCC)
+			{
+				switch (formatFourCC)
+				{
+					case 0x71: // D3DFMT_A16B16G16R16F
+						format = TextureFormat.R16G16B16A16_SFLOAT;
+						break;
+					case 0x74: // D3DFMT_A32B32G32R32F
+						format = TextureFormat.R32G32B32A32_SFLOAT;
+						break;
+					case FOURCC_DXT1:
+						format = TextureFormat.BC1;
+						break;
+					case FOURCC_DXT3:
+						format = TextureFormat.BC2;
+						break;
+					case FOURCC_DXT5:
+						format = TextureFormat.BC3;
+						break;
+					case FOURCC_DX10:
+						// If the fourCC is DX10, there is an extra header with additional format information.
+						uint dxgiFormat = reader.ReadUInt32();
+
+						// These values are taken from the DXGI_FORMAT enum.
+						switch (dxgiFormat)
+						{
+							case 2:
+								format = TextureFormat.R32G32B32A32_SFLOAT;
+								break;
+
+							case 10:
+								format = TextureFormat.R16G16B16A16_SFLOAT;
+								break;
+
+							case 71:
+								format = TextureFormat.BC1;
+								break;
+
+							case 74:
+								format = TextureFormat.BC2;
+								break;
+
+							case 77:
+								format = TextureFormat.BC3;
+								break;
+
+							case 98:
+								format = TextureFormat.BC7;
+								break;
+
+							default:
+								throw new NotSupportedException(
+									"Unsupported DDS texture format"
+								);
+						}
+
+						uint resourceDimension = reader.ReadUInt32();
+
+						// These values are taken from the D3D10_RESOURCE_DIMENSION enum.
+						switch (resourceDimension)
+						{
+							case 0: // Unknown
+							case 1: // Buffer
+								throw new NotSupportedException(
+									"Unsupported DDS texture format"
+								);
+							default:
+								break;
+						}
+
+						/*
+						 * This flag seemingly only indicates if the texture is a cube map.
+						 * This is already determined above. Cool!
+						 */
+						uint miscFlag = reader.ReadUInt32();
+
+						/*
+						 * Indicates the number of elements in the texture array.
+						 * We don't support texture arrays so just throw if it's greater than 1.
+						 */
+						uint arraySize = reader.ReadUInt32();
+
+						if (arraySize > 1)
+						{
+							throw new NotSupportedException(
+								"Unsupported DDS texture format"
+							);
+						}
+
+						reader.ReadUInt32(); // reserved
+
+						break;
+					default:
+						throw new NotSupportedException(
+							"Unsupported DDS texture format"
+						);
+				}
+			}
+			else if ((formatFlags & DDPF_RGB) == DDPF_RGB)
+			{
+				if (	formatRGBBitCount != 32 ||
+					formatRBitMask != 0x00FF0000 ||
+					formatGBitMask != 0x0000FF00 ||
+					formatBBitMask != 0x000000FF ||
+					formatABitMask != 0xFF000000	)
+				{
+					throw new NotSupportedException(
+						"Unsupported DDS texture format"
+					);
+				}
+
+				format = TextureFormat.B8G8R8A8;
+			}
+			else
+			{
+				throw new NotSupportedException(
+					"Unsupported DDS texture format"
+				);
+			}
+		}
+
+		private static int CalculateDDSLevelSize(
+			int width,
+			int height,
+			TextureFormat format
+		) {
+			if (format == TextureFormat.R8G8B8A8)
+			{
+				return (((width * 32) + 7) / 8) * height;
+			}
+			else if (format == TextureFormat.R16G16B16A16_SFLOAT)
+			{
+				return (((width * 64) + 7) / 8) * height;
+			}
+			else if (format == TextureFormat.R32G32B32A32_SFLOAT)
+			{
+				return (((width * 128) + 7) / 8) * height;
+			}
+			else
+			{
+				int blockSize = 16;
+				if (format == TextureFormat.BC1)
+				{
+					blockSize = 8;
+				}
+				width = System.Math.Max(width, 1);
+				height = System.Math.Max(height, 1);
+				return (
+					((width + 3) / 4) *
+					((height + 3) / 4) *
+					blockSize
+				);
+			}
+		}
 	}
 }

src/Graphics/State/ColorAttachmentBlendState.cs

@@ -2,7 +2,7 @@
 
 namespace MoonWorks.Graphics
 {
-	public struct ColorTargetBlendState
+	public struct ColorAttachmentBlendState
 	{
 		/// <summary>
 		/// If disabled, no blending will occur.
@@ -43,7 +43,7 @@ namespace MoonWorks.Graphics
 		/// </summary>
 		public BlendFactor SourceColorBlendFactor;
 
-		public static readonly ColorTargetBlendState Additive = new ColorTargetBlendState
+		public static readonly ColorAttachmentBlendState Additive = new ColorAttachmentBlendState
 		{
 			BlendEnable = true,
 			AlphaBlendOp = BlendOp.Add,
@@ -55,7 +55,7 @@ namespace MoonWorks.Graphics
 			DestinationAlphaBlendFactor = BlendFactor.One
 		};
 
-		public static readonly ColorTargetBlendState AlphaBlend = new ColorTargetBlendState
+		public static readonly ColorAttachmentBlendState AlphaBlend = new ColorAttachmentBlendState
 		{
 			BlendEnable = true,
 			AlphaBlendOp = BlendOp.Add,
@@ -67,7 +67,7 @@ namespace MoonWorks.Graphics
 			DestinationAlphaBlendFactor = BlendFactor.OneMinusSourceAlpha
 		};
 
-		public static readonly ColorTargetBlendState NonPremultiplied = new ColorTargetBlendState
+		public static readonly ColorAttachmentBlendState NonPremultiplied = new ColorAttachmentBlendState
 		{
 			BlendEnable = true,
 			AlphaBlendOp = BlendOp.Add,
@@ -79,7 +79,7 @@ namespace MoonWorks.Graphics
 			DestinationAlphaBlendFactor = BlendFactor.OneMinusSourceAlpha
 		};
 
-		public static readonly ColorTargetBlendState Opaque = new ColorTargetBlendState
+		public static readonly ColorAttachmentBlendState Opaque = new ColorAttachmentBlendState
 		{
 			BlendEnable = true,
 			AlphaBlendOp = BlendOp.Add,
@@ -91,21 +91,21 @@ namespace MoonWorks.Graphics
 			DestinationAlphaBlendFactor = BlendFactor.Zero
 		};
 
-		public static readonly ColorTargetBlendState None = new ColorTargetBlendState
+		public static readonly ColorAttachmentBlendState None = new ColorAttachmentBlendState
 		{
 			BlendEnable = false,
 			ColorWriteMask = ColorComponentFlags.RGBA
 		};
 
-		public static readonly ColorTargetBlendState Disable = new ColorTargetBlendState
+		public static readonly ColorAttachmentBlendState Disable = new ColorAttachmentBlendState
 		{
 			BlendEnable = false,
 			ColorWriteMask = ColorComponentFlags.None
 		};
 
-		public Refresh.ColorTargetBlendState ToRefreshColorTargetBlendState()
+		public Refresh.ColorAttachmentBlendState ToRefresh()
 		{
-			return new Refresh.ColorTargetBlendState
+			return new Refresh.ColorAttachmentBlendState
 			{
 				blendEnable = Conversions.BoolToByte(BlendEnable),
 				alphaBlendOp = (Refresh.BlendOp) AlphaBlendOp,

src/Graphics/State/ColorBlendState.cs

@@ -1,14 +0,0 @@
-namespace MoonWorks.Graphics
-{
-	/// <summary>
-	/// Describes how the graphics pipeline will blend colors.
-	/// You must provide one ColorTargetBlendState per color target in the pipeline.
-	/// </summary>
-	public unsafe struct ColorBlendState
-	{
-		public bool LogicOpEnable;
-		public LogicOp LogicOp;
-		public BlendConstants BlendConstants;
-		public ColorTargetBlendState[] ColorTargetBlendStates;
-	}
-}

src/Graphics/State/ComputeShaderInfo.cs

@@ -0,0 +1,50 @@
+using System.Runtime.InteropServices;
+
+namespace MoonWorks.Graphics
+{
+	/// <summary>
+	/// Information that the pipeline needs about a shader.
+	/// </summary>
+	public struct ComputeShaderInfo
+	{
+		public ShaderModule ShaderModule;
+		public string EntryPointName;
+		public uint UniformBufferSize;
+		public uint BufferBindingCount;
+		public uint ImageBindingCount;
+
+		public unsafe static ComputeShaderInfo Create<T>(
+			ShaderModule shaderModule,
+			string entryPointName,
+			uint bufferBindingCount,
+			uint imageBindingCount
+		) where T : unmanaged
+		{
+			return new ComputeShaderInfo
+			{
+				ShaderModule = shaderModule,
+				EntryPointName = entryPointName,
+				UniformBufferSize = (uint) sizeof(T),
+				BufferBindingCount = bufferBindingCount,
+				ImageBindingCount = imageBindingCount
+			};
+		}
+
+        public static ComputeShaderInfo Create(
+            ShaderModule shaderModule,
+            string entryPointName,
+            uint bufferBindingCount,
+            uint imageBindingCount
+        )
+        {
+            return new ComputeShaderInfo
+			{
+				ShaderModule = shaderModule,
+				EntryPointName = entryPointName,
+				UniformBufferSize = 0,
+				BufferBindingCount = bufferBindingCount,
+				ImageBindingCount = imageBindingCount
+			};
+        }
+	}
+}

src/Graphics/State/GraphicsPipelineAttachmentInfo.cs

@@ -5,9 +5,25 @@ namespace MoonWorks.Graphics
 	/// </summary>
 	public struct GraphicsPipelineAttachmentInfo
 	{
-		public ColorAttachmentDescription[] colorAttachmentDescriptions;
+		public ColorAttachmentDescription[] ColorAttachmentDescriptions;
-		public uint colorAttachmentCount;
+		public bool HasDepthStencilAttachment;
-		public bool hasDepthStencilAttachment;
+		public TextureFormat DepthStencilFormat;
-		public TextureFormat depthStencilFormat;
+
+		public GraphicsPipelineAttachmentInfo(
+			params ColorAttachmentDescription[] colorAttachmentDescriptions
+		) {
+			ColorAttachmentDescriptions = colorAttachmentDescriptions;
+			HasDepthStencilAttachment = false;
+			DepthStencilFormat = TextureFormat.D16;
+		}
+
+		public GraphicsPipelineAttachmentInfo(
+			TextureFormat depthStencilFormat,
+			params ColorAttachmentDescription[] colorAttachmentDescriptions
+		) {
+			ColorAttachmentDescriptions = colorAttachmentDescriptions;
+			HasDepthStencilAttachment = true;
+			DepthStencilFormat = depthStencilFormat;
+		}
 	}
 }

src/Graphics/State/GraphicsPipelineCreateInfo.cs

@@ -2,16 +2,14 @@
 {
 	public struct GraphicsPipelineCreateInfo
 	{
-		public ColorBlendState ColorBlendState;
 		public DepthStencilState DepthStencilState;
-		public ShaderStageState VertexShaderState;
+		public GraphicsShaderInfo VertexShaderInfo;
-		public ShaderStageState FragmentShaderState;
+		public GraphicsShaderInfo FragmentShaderInfo;
 		public MultisampleState MultisampleState;
-		public GraphicsPipelineLayoutInfo PipelineLayoutInfo;
 		public RasterizerState RasterizerState;
 		public PrimitiveType PrimitiveType;
 		public VertexInputState VertexInputState;
-		public ViewportState ViewportState;
 		public GraphicsPipelineAttachmentInfo AttachmentInfo;
+		public BlendConstants BlendConstants;
 	}
 }

src/Graphics/State/GraphicsPipelineLayoutInfo.cs

@@ -1,11 +0,0 @@
-namespace MoonWorks.Graphics
-{
-	/// <summary>
-	/// Describes how many samplers will be used in each shader stage.
-	/// </summary>
-	public struct GraphicsPipelineLayoutInfo
-	{
-		public uint VertexSamplerBindingCount;
-		public uint FragmentSamplerBindingCount;
-	}
-}

src/Graphics/State/GraphicsShaderInfo.cs

@@ -0,0 +1,44 @@
+using System.Runtime.InteropServices;
+
+namespace MoonWorks.Graphics
+{
+	/// <summary>
+	/// Information that the pipeline needs about a shader.
+	/// </summary>
+	public struct GraphicsShaderInfo
+	{
+		public ShaderModule ShaderModule;
+		public string EntryPointName;
+		public uint UniformBufferSize;
+		public uint SamplerBindingCount;
+
+		public unsafe static GraphicsShaderInfo Create<T>(
+			ShaderModule shaderModule,
+			string entryPointName,
+			uint samplerBindingCount
+		) where T : unmanaged
+		{
+			return new GraphicsShaderInfo
+			{
+				ShaderModule = shaderModule,
+				EntryPointName = entryPointName,
+				UniformBufferSize = (uint) sizeof(T),
+				SamplerBindingCount = samplerBindingCount
+			};
+		}
+
+		public static GraphicsShaderInfo Create(
+			ShaderModule shaderModule,
+			string entryPointName,
+			uint samplerBindingCount
+		) {
+			return new GraphicsShaderInfo
+			{
+				ShaderModule = shaderModule,
+				EntryPointName = entryPointName,
+				UniformBufferSize = 0,
+				SamplerBindingCount = samplerBindingCount
+			};
+		}
+	}
+}

src/Graphics/State/RasterizerState.cs

@@ -41,18 +41,12 @@
 		/// </summary>
 		public FrontFace FrontFace;
 
-		/// <summary>
-		/// Describes the width of the line rendering in terms of pixels.
-		/// </summary>
-		public float LineWidth;
-
 		public static readonly RasterizerState CW_CullFront = new RasterizerState
 		{
 			CullMode = CullMode.Front,
 			FrontFace = FrontFace.Clockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CW_CullBack = new RasterizerState
@@ -60,8 +54,7 @@
 			CullMode = CullMode.Back,
 			FrontFace = FrontFace.Clockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CW_CullNone = new RasterizerState
@@ -69,8 +62,7 @@
 			CullMode = CullMode.None,
 			FrontFace = FrontFace.Clockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CW_Wireframe = new RasterizerState
@@ -78,8 +70,7 @@
 			CullMode = CullMode.None,
 			FrontFace = FrontFace.Clockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CCW_CullFront = new RasterizerState
@@ -87,8 +78,7 @@
 			CullMode = CullMode.Front,
 			FrontFace = FrontFace.CounterClockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CCW_CullBack = new RasterizerState
@@ -96,8 +86,7 @@
 			CullMode = CullMode.Back,
 			FrontFace = FrontFace.CounterClockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CCW_CullNone = new RasterizerState
@@ -105,8 +94,7 @@
 			CullMode = CullMode.None,
 			FrontFace = FrontFace.CounterClockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 
 		public static readonly RasterizerState CCW_Wireframe = new RasterizerState
@@ -114,8 +102,7 @@
 			CullMode = CullMode.None,
 			FrontFace = FrontFace.CounterClockwise,
 			FillMode = FillMode.Fill,
-			DepthBiasEnable = false,
+			DepthBiasEnable = false
-			LineWidth = 1f
 		};
 	}
 }

src/Graphics/State/ShaderStageState.cs

@@ -1,12 +0,0 @@
-namespace MoonWorks.Graphics
-{
-	/// <summary>
-	/// Specifies how the graphics pipeline will make use of a shader.
-	/// </summary>
-	public struct ShaderStageState
-	{
-		public ShaderModule ShaderModule;
-		public string EntryPointName;
-		public uint UniformBufferSize;
-	}
-}

src/Graphics/State/VertexInputState.cs

@@ -7,5 +7,19 @@
 	{
 		public VertexBinding[] VertexBindings;
 		public VertexAttribute[] VertexAttributes;
+
+		public static readonly VertexInputState Empty = new VertexInputState
+		{
+			VertexBindings = new VertexBinding[0],
+			VertexAttributes = new VertexAttribute[0]
+		};
+
+		public VertexInputState(
+			VertexBinding vertexBinding,
+			params VertexAttribute[] vertexAttributes
+		) {
+			VertexBindings = new VertexBinding[] { vertexBinding };
+			VertexAttributes = vertexAttributes;
+		}
 	}
 }

src/Graphics/State/ViewportState.cs

@@ -1,11 +0,0 @@
-namespace MoonWorks.Graphics
-{
-	/// <summary>
-	/// Describes the dimensions of viewports and scissor areas.
-	/// </summary>
-	public struct ViewportState
-	{
-		public Viewport[] Viewports;
-		public Rect[] Scissors;
-	}
-}

src/Graphics/Utility/Bytecode.cs

@@ -1,33 +0,0 @@
-using System.IO;
-
-namespace MoonWorks.Graphics
-{
-	public static class Bytecode
-	{
-		public static uint[] ReadBytecodeAsUInt32(string filePath)
-		{
-			byte[] data;
-			int size;
-			using (FileStream stream = new FileStream(filePath, FileMode.Open, FileAccess.Read))
-			{
-				size = (int) stream.Length;
-				data = new byte[size];
-				stream.Read(data, 0, size);
-			}
-
-			uint[] uintData = new uint[size / 4];
-			using (var memoryStream = new MemoryStream(data))
-			{
-				using (var reader = new BinaryReader(memoryStream))
-				{
-					for (int i = 0; i < size / 4; i++)
-					{
-						uintData[i] = reader.ReadUInt32();
-					}
-				}
-			}
-
-			return uintData;
-		}
-	}
-}

src/Graphics/Utility/Conversions.cs

@@ -11,5 +11,39 @@
 		{
 			return b != 0;
 		}
+
+		public static Graphics.VertexElementFormat TypeToVertexElementFormat(System.Type type)
+		{
+			if (type == typeof(uint))
+			{
+				return Graphics.VertexElementFormat.UInt;
+			}
+			if (type == typeof(float))
+			{
+				return Graphics.VertexElementFormat.Float;
+			}
+			else if (type == typeof(Math.Float.Vector2))
+			{
+				return Graphics.VertexElementFormat.Vector2;
+			}
+			else if (type == typeof(Math.Float.Vector3))
+			{
+				return Graphics.VertexElementFormat.Vector3;
+			}
+			else if (type == typeof(Math.Float.Vector4))
+			{
+				return Graphics.VertexElementFormat.Vector4;
+			}
+			else if (type == typeof(Graphics.Color))
+			{
+				return Graphics.VertexElementFormat.Color;
+			}
+			else
+			{
+				throw new System.ArgumentException(
+					"Cannot automatically convert this type to a VertexElementFormat!"
+				);
+			}
+		}
 	}
 }

src/Input/Axis.cs

@@ -0,0 +1,37 @@
+using MoonWorks.Math;
+using SDL2;
+
+namespace MoonWorks.Input
+{
+	public class Axis
+	{
+		public Gamepad Parent { get; }
+		SDL.SDL_GameControllerAxis SDL_Axis;
+
+		public AxisCode Code { get; private set; }
+
+		/// <summary>
+		/// An axis value between -1 and 1.
+		/// </summary>
+		public float Value { get; private set; }
+
+		public Axis(
+			Gamepad parent,
+			AxisCode code,
+			SDL.SDL_GameControllerAxis sdlAxis
+		) {
+			Parent = parent;
+			SDL_Axis = sdlAxis;
+			Code = code;
+		}
+
+		internal void Update()
+		{
+			Value = MathHelper.Normalize(
+				SDL.SDL_GameControllerGetAxis(Parent.Handle, SDL_Axis),
+				short.MinValue, short.MaxValue,
+				-1, 1
+			);
+		}
+	}
+}

src/Input/AxisButtonCode.cs

@@ -0,0 +1,14 @@
+namespace MoonWorks.Input
+{
+	public enum AxisButtonCode
+	{
+		LeftX_Left,
+		LeftX_Right,
+		LeftY_Up,
+		LeftY_Down,
+		RightX_Left,
+		RightX_Right,
+		RightY_Up,
+		RightY_Down
+	}
+}

src/Input/AxisCode.cs

@@ -0,0 +1,11 @@
+namespace MoonWorks.Input
+{
+	// Enum values are equivalent to SDL GameControllerAxis
+	public enum AxisCode
+	{
+		LeftX,
+		LeftY,
+		RightX,
+		RightY
+	}
+}

src/Input/ButtonCode.cs

@@ -0,0 +1,22 @@
+namespace MoonWorks.Input
+{
+	// Enum values are equivalent to the SDL GameControllerButton value.
+	public enum GamepadButtonCode
+	{
+		A,
+		B,
+		X,
+		Y,
+		Back,
+		Guide,
+		Start,
+		LeftStick,
+		RightStick,
+		LeftShoulder,
+		RightShoulder,
+		DpadUp,
+		DpadDown,
+		DpadLeft,
+		DpadRight
+	}
+}

src/Input/ButtonState.cs

@@ -1,30 +1,60 @@
 namespace MoonWorks.Input
 {
-	public class ButtonState
+	public struct ButtonState
 	{
-		private ButtonStatus ButtonStatus { get; set; }
+		public ButtonStatus ButtonStatus { get; }
 
 		public bool IsPressed => ButtonStatus == ButtonStatus.Pressed;
 		public bool IsHeld => ButtonStatus == ButtonStatus.Held;
 		public bool IsDown => ButtonStatus == ButtonStatus.Pressed || ButtonStatus == ButtonStatus.Held;
 		public bool IsReleased => ButtonStatus == ButtonStatus.Released;
 
-		internal void Update(bool isPressed)
+		public ButtonState(ButtonStatus buttonStatus)
+		{
+			ButtonStatus = buttonStatus;
+		}
+
+		internal ButtonState Update(bool isPressed)
 		{
 			if (isPressed)
 			{
 				if (ButtonStatus == ButtonStatus.Pressed)
 				{
-					ButtonStatus = ButtonStatus.Held;
+					return new ButtonState(ButtonStatus.Held);
 				}
 				else if (ButtonStatus == ButtonStatus.Released)
 				{
-					ButtonStatus = ButtonStatus.Pressed;
+					return new ButtonState(ButtonStatus.Pressed);
+				}
+				else if (ButtonStatus == ButtonStatus.Held)
+				{
+					return new ButtonState(ButtonStatus.Held);
 				}
 			}
-			else
+
+			return new ButtonState(ButtonStatus.Released);
+		}
+
+		public static ButtonState operator |(ButtonState a, ButtonState b)
+		{
+			if (a.ButtonStatus == ButtonStatus.Released)
 			{
-				ButtonStatus = ButtonStatus.Released;
+				return b;
+			}
+			else if (a.ButtonStatus == ButtonStatus.Pressed)
+			{
+				if (b.ButtonStatus == ButtonStatus.Held)
+				{
+					return new ButtonState(ButtonStatus.Held);
+				}
+				else
+				{
+					return a;
+				}
+			}
+			else // held
+			{
+				return a;
 			}
 		}
 	}

src/Input/ButtonStatus.cs

@@ -1,6 +1,6 @@
 namespace MoonWorks.Input
 {
-	internal enum ButtonStatus
+	public enum ButtonStatus
 	{
 		/// <summary>
 		/// Indicates that the input is not pressed.

src/Input/DeviceKind.cs

@@ -0,0 +1,10 @@
+namespace MoonWorks.Input
+{
+    public enum DeviceKind
+    {
+		None,
+        Keyboard,
+        Mouse,
+        Gamepad,
+    }
+}

src/Input/Gamepad.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using MoonWorks.Math;
 using SDL2;
 
@@ -7,35 +8,241 @@ namespace MoonWorks.Input
 	public class Gamepad
 	{
 		internal IntPtr Handle;
+		internal int JoystickInstanceID;
 
-		public ButtonState A { get; } = new ButtonState();
+		public int Slot { get; internal set; }
-		public ButtonState B { get; } = new ButtonState();
-		public ButtonState X { get; } = new ButtonState();
-		public ButtonState Y { get; } = new ButtonState();
-		public ButtonState Back { get; } = new ButtonState();
-		public ButtonState Guide { get; } = new ButtonState();
-		public ButtonState Start { get; } = new ButtonState();
-		public ButtonState LeftStick { get; } = new ButtonState();
-		public ButtonState RightStick { get; } = new ButtonState();
-		public ButtonState LeftShoulder { get; } = new ButtonState();
-		public ButtonState RightShoulder { get; } = new ButtonState();
-		public ButtonState DpadUp { get; } = new ButtonState();
-		public ButtonState DpadDown { get; } = new ButtonState();
-		public ButtonState DpadLeft { get; } = new ButtonState();
-		public ButtonState DpadRight { get; } = new ButtonState();
 
-		public float LeftX { get; private set; }
+		public GamepadButton A { get; }
-		public float LeftY { get; private set; }
+		public GamepadButton B { get; }
-		public float RightX { get; private set; }
+		public GamepadButton X { get; }
-		public float RightY { get; private set; }
+		public GamepadButton Y { get; }
-		public float TriggerLeft { get; private set; }
+		public GamepadButton Back { get; }
-		public float TriggerRight { get; private set; }
+		public GamepadButton Guide { get; }
+		public GamepadButton Start { get; }
+		public GamepadButton LeftStick { get; }
+		public GamepadButton RightStick { get; }
+		public GamepadButton LeftShoulder { get; }
+		public GamepadButton RightShoulder { get; }
+		public GamepadButton DpadUp { get; }
+		public GamepadButton DpadDown { get; }
+		public GamepadButton DpadLeft { get; }
+		public GamepadButton DpadRight { get; }
 
-		internal Gamepad(IntPtr handle)
+		public Axis LeftX { get; }
+		public Axis LeftY { get; }
+		public Axis RightX { get; }
+		public Axis RightY { get; }
+
+		public AxisButton LeftXLeft { get; }
+		public AxisButton LeftXRight { get; }
+		public AxisButton LeftYUp { get; }
+		public AxisButton LeftYDown { get; }
+
+		public AxisButton RightXLeft { get; }
+		public AxisButton RightXRight { get; }
+		public AxisButton RightYUp { get; }
+		public AxisButton RightYDown { get; }
+
+		public Trigger TriggerLeft { get; }
+		public Trigger TriggerRight { get; }
+
+		public TriggerButton TriggerLeftButton { get; }
+		public TriggerButton TriggerRightButton { get; }
+
+		public bool IsDummy => Handle == IntPtr.Zero;
+
+		public bool AnyPressed { get; private set; }
+		public VirtualButton AnyPressedButton { get; private set; }
+
+		private Dictionary<SDL.SDL_GameControllerButton, GamepadButton> EnumToButton;
+		private Dictionary<SDL.SDL_GameControllerAxis, Axis> EnumToAxis;
+		private Dictionary<SDL.SDL_GameControllerAxis, Trigger> EnumToTrigger;
+
+		private Dictionary<AxisButtonCode, AxisButton> AxisButtonCodeToAxisButton;
+		private Dictionary<TriggerCode, TriggerButton> TriggerCodeToTriggerButton;
+
+		private VirtualButton[] VirtualButtons;
+
+		internal Gamepad(IntPtr handle, int slot)
 		{
 			Handle = handle;
+			Slot = slot;
+
+			IntPtr joystickHandle = SDL.SDL_GameControllerGetJoystick(Handle);
+			JoystickInstanceID = SDL.SDL_JoystickInstanceID(joystickHandle);
+
+			AnyPressed = false;
+
+			A = new GamepadButton(this, GamepadButtonCode.A, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_A);
+			B = new GamepadButton(this, GamepadButtonCode.B, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_B);
+			X = new GamepadButton(this, GamepadButtonCode.X, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_X);
+			Y = new GamepadButton(this, GamepadButtonCode.Y, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_Y);
+
+			Back = new GamepadButton(this, GamepadButtonCode.Back, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_BACK);
+			Guide = new GamepadButton(this, GamepadButtonCode.Guide, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_GUIDE);
+			Start = new GamepadButton(this, GamepadButtonCode.Start, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_START);
+
+			LeftStick = new GamepadButton(this, GamepadButtonCode.LeftStick, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_LEFTSTICK);
+			RightStick = new GamepadButton(this, GamepadButtonCode.RightStick, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_RIGHTSTICK);
+
+			LeftShoulder = new GamepadButton(this, GamepadButtonCode.LeftShoulder, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_LEFTSHOULDER);
+			RightShoulder = new GamepadButton(this, GamepadButtonCode.RightShoulder, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_RIGHTSHOULDER);
+
+			DpadUp = new GamepadButton(this, GamepadButtonCode.DpadUp, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_UP);
+			DpadDown = new GamepadButton(this, GamepadButtonCode.DpadDown, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_DOWN);
+			DpadLeft = new GamepadButton(this, GamepadButtonCode.DpadLeft, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_LEFT);
+			DpadRight = new GamepadButton(this, GamepadButtonCode.DpadRight, SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_RIGHT);
+
+			LeftX = new Axis(this, AxisCode.LeftX, SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_LEFTX);
+			LeftY = new Axis(this, AxisCode.LeftY, SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_LEFTY);
+			RightX = new Axis(this, AxisCode.RightX, SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_RIGHTX);
+			RightY = new Axis(this, AxisCode.RightY, SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_RIGHTY);
+
+			LeftXLeft = new AxisButton(LeftX, false);
+			LeftXRight = new AxisButton(LeftX, true);
+			LeftYUp = new AxisButton(LeftY, false);
+			LeftYDown = new AxisButton(LeftY, true);
+
+			RightXLeft = new AxisButton(RightX, false);
+			RightXRight = new AxisButton(RightX, true);
+			RightYUp = new AxisButton(RightY, false);
+			RightYDown = new AxisButton(RightY, true);
+
+			TriggerLeft = new Trigger(this, TriggerCode.Left, SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_TRIGGERLEFT);
+			TriggerRight = new Trigger(this, TriggerCode.Right, SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_TRIGGERRIGHT);
+
+			TriggerLeftButton = new TriggerButton(TriggerLeft);
+			TriggerRightButton = new TriggerButton(TriggerRight);
+
+			EnumToButton = new Dictionary<SDL.SDL_GameControllerButton, GamepadButton>
+			{
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_A, A },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_B, B },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_X, X },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_Y, Y },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_BACK, Back },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_GUIDE, Guide },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_START, Start },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_LEFTSTICK, LeftStick },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_RIGHTSTICK, RightStick },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_LEFTSHOULDER, LeftShoulder },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_RIGHTSHOULDER, RightShoulder },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_UP, DpadUp },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_DOWN, DpadDown },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_LEFT, DpadLeft },
+				{ SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_RIGHT, DpadRight }
+			};
+
+			EnumToAxis = new Dictionary<SDL.SDL_GameControllerAxis, Axis>
+			{
+				{ SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_LEFTX, LeftX },
+				{ SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_LEFTY, LeftY },
+				{ SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_RIGHTX, RightX },
+				{ SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_RIGHTY, RightY }
+			};
+
+			EnumToTrigger = new Dictionary<SDL.SDL_GameControllerAxis, Trigger>
+			{
+				{ SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_TRIGGERLEFT, TriggerLeft },
+				{ SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_TRIGGERRIGHT, TriggerRight }
+			};
+
+			AxisButtonCodeToAxisButton = new Dictionary<AxisButtonCode, AxisButton>
+			{
+				{ AxisButtonCode.LeftX_Left, LeftXLeft },
+				{ AxisButtonCode.LeftX_Right, LeftXRight },
+				{ AxisButtonCode.LeftY_Down, LeftYDown },
+				{ AxisButtonCode.LeftY_Up, LeftYUp },
+				{ AxisButtonCode.RightX_Left, RightXLeft },
+				{ AxisButtonCode.RightX_Right, RightXRight },
+				{ AxisButtonCode.RightY_Up, RightYUp },
+				{ AxisButtonCode.RightY_Down, RightYDown }
+			};
+
+			TriggerCodeToTriggerButton = new Dictionary<TriggerCode, TriggerButton>
+			{
+				{ TriggerCode.Left, TriggerLeftButton },
+				{ TriggerCode.Right, TriggerRightButton }
+			};
+
+			VirtualButtons = new VirtualButton[]
+			{
+				A,
+				B,
+				X,
+				Y,
+				Back,
+				Guide,
+				Start,
+				LeftStick,
+				RightStick,
+				LeftShoulder,
+				RightShoulder,
+				DpadUp,
+				DpadDown,
+				DpadLeft,
+				DpadRight,
+				LeftXLeft,
+				LeftXRight,
+				LeftYUp,
+				LeftYDown,
+				RightXLeft,
+				RightXRight,
+				RightYUp,
+				RightYDown,
+				TriggerLeftButton,
+				TriggerRightButton
+			};
 		}
 
+		internal void Update()
+		{
+			AnyPressed = false;
+
+			if (!IsDummy)
+			{
+				foreach (var button in EnumToButton.Values)
+				{
+					button.Update();
+				}
+
+				foreach (var axis in EnumToAxis.Values)
+				{
+					axis.Update();
+				}
+
+				foreach (var trigger in EnumToTrigger.Values)
+				{
+					trigger.Update();
+				}
+
+				LeftXLeft.Update();
+				LeftXRight.Update();
+				LeftYUp.Update();
+				LeftYDown.Update();
+				RightXLeft.Update();
+				RightXRight.Update();
+				RightYUp.Update();
+				RightYDown.Update();
+
+				TriggerLeftButton.Update();
+				TriggerRightButton.Update();
+
+				foreach (var button in VirtualButtons)
+				{
+					if (button.IsPressed)
+					{
+						AnyPressed = true;
+						AnyPressedButton = button;
+						break;
+					}
+				}
+			}
+		}
+
+		/// <summary>
+		/// Sets vibration values on the left and right motors.
+		/// </summary>
 		public bool SetVibration(float leftMotor, float rightMotor, uint durationInMilliseconds)
 		{
 			return SDL.SDL_GameControllerRumble(
@@ -46,53 +253,37 @@ namespace MoonWorks.Input
 			) == 0;
 		}
 
-		internal void Update()
+		public GamepadButton Button(GamepadButtonCode buttonCode)
 		{
-			A.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_A));
+			return EnumToButton[(SDL.SDL_GameControllerButton) buttonCode];
-			B.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_B));
-			X.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_X));
-			Y.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_Y));
-			Back.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_BACK));
-			Guide.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_GUIDE));
-			Start.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_START));
-			LeftStick.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_LEFTSTICK));
-			RightStick.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_RIGHTSTICK));
-			LeftShoulder.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_LEFTSHOULDER));
-			RightShoulder.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_RIGHTSHOULDER));
-			DpadUp.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_UP));
-			DpadDown.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_DOWN));
-			DpadLeft.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_LEFT));
-			DpadRight.Update(IsPressed(SDL.SDL_GameControllerButton.SDL_CONTROLLER_BUTTON_DPAD_RIGHT));
-
-			LeftX = UpdateAxis(SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_LEFTX);
-			LeftY = UpdateAxis(SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_LEFTY);
-			RightX = UpdateAxis(SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_RIGHTX);
-			RightY = UpdateAxis(SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_RIGHTY);
-			TriggerLeft = UpdateTrigger(SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_TRIGGERLEFT);
-			TriggerRight = UpdateTrigger(SDL.SDL_GameControllerAxis.SDL_CONTROLLER_AXIS_TRIGGERRIGHT);
 		}
 
-		private bool IsPressed(SDL.SDL_GameControllerButton button)
+		public AxisButton Button(AxisButtonCode axisButtonCode)
 		{
-			return MoonWorks.Conversions.ByteToBool(SDL.SDL_GameControllerGetButton(Handle, button));
+			return AxisButtonCodeToAxisButton[axisButtonCode];
 		}
 
-		private float UpdateAxis(SDL.SDL_GameControllerAxis axis)
+		public TriggerButton Button(TriggerCode triggerCode)
 		{
-			var axisValue = SDL.SDL_GameControllerGetAxis(Handle, axis);
+			return TriggerCodeToTriggerButton[triggerCode];
-			return Normalize(axisValue, short.MinValue, short.MaxValue, -1, 1);
 		}
 
-		// Triggers only go from 0 to short.MaxValue
+		/// <summary>
-		private float UpdateTrigger(SDL.SDL_GameControllerAxis trigger)
+		/// Obtains the axis value given an AxisCode.
+		/// </summary>
+		/// <returns>A value between -1 and 1.</returns>
+		public float AxisValue(AxisCode axisCode)
 		{
-			var triggerValue = SDL.SDL_GameControllerGetAxis(Handle, trigger);
+			return EnumToAxis[(SDL.SDL_GameControllerAxis) axisCode].Value;
-			return Normalize(triggerValue, 0, short.MaxValue, 0, 1);
 		}
 
-		private float Normalize(float value, short min, short max, short newMin, short newMax)
+		/// <summary>
+		/// Obtains the trigger value given an TriggerCode.
+		/// </summary>
+		/// <returns>A value between 0 and 1.</returns>
+		public float TriggerValue(TriggerCode triggerCode)
 		{
-			return ((value - min) * (newMax - newMin)) / (max - min) + newMin;
+			return EnumToTrigger[(SDL.SDL_GameControllerAxis) triggerCode].Value;
 		}
 	}
 }

src/Input/Input.cs

@@ -1,54 +1,116 @@
 using SDL2;
 using System;
-using System.Collections.Generic;
 
 namespace MoonWorks.Input
 {
 	public class Inputs
 	{
+		public const int MAX_GAMEPADS = 4;
+
 		public Keyboard Keyboard { get; }
 		public Mouse Mouse { get; }
 
-		List<Gamepad> gamepads = new List<Gamepad>();
+		Gamepad[] gamepads;
 
 		public static event Action<char> TextInput;
 
+		public bool AnyPressed { get; private set; }
+		public VirtualButton AnyPressedButton { get; private set; }
+
 		internal Inputs()
 		{
 			Keyboard = new Keyboard();
 			Mouse = new Mouse();
 
-			for (int i = 0; i < SDL.SDL_NumJoysticks(); i++)
+			gamepads = new Gamepad[MAX_GAMEPADS];
+
+			// initialize dummy controllers
+			for (var slot = 0; slot < MAX_GAMEPADS; slot += 1)
 			{
-				if (SDL.SDL_IsGameController(i) == SDL.SDL_bool.SDL_TRUE)
+				gamepads[slot] = new Gamepad(IntPtr.Zero, slot);
-				{
-					gamepads.Add(new Gamepad(SDL.SDL_GameControllerOpen(i)));
-				}
 			}
 		}
 
 		// Assumes that SDL_PumpEvents has been called!
 		internal void Update()
 		{
+			AnyPressed = false;
+			AnyPressedButton = default; // DeviceKind.None
+
+			Mouse.Wheel = 0;
 			Keyboard.Update();
+
+			if (Keyboard.AnyPressed)
+			{
+				AnyPressed = true;
+				AnyPressedButton = Keyboard.AnyPressedButton;
+			}
+
 			Mouse.Update();
 
+			if (Mouse.AnyPressed)
+			{
+				AnyPressed = true;
+				AnyPressedButton = Mouse.AnyPressedButton;
+			}
+
 			foreach (var gamepad in gamepads)
 			{
 				gamepad.Update();
+
+				if (gamepad.AnyPressed)
+				{
+					AnyPressed = true;
+					AnyPressedButton = gamepad.AnyPressedButton;
+				}
 			}
 		}
 
 		public bool GamepadExists(int slot)
 		{
-			return slot < gamepads.Count;
+			if (slot < 0 || slot >= MAX_GAMEPADS)
+			{
+				return false;
+			}
+
+			return !gamepads[slot].IsDummy;
 		}
 
+		// From 0-4
 		public Gamepad GetGamepad(int slot)
 		{
 			return gamepads[slot];
 		}
 
+		internal void AddGamepad(int index)
+		{
+			for (var slot = 0; slot < MAX_GAMEPADS; slot += 1)
+			{
+				if (!GamepadExists(slot))
+				{
+					gamepads[slot].Handle = SDL.SDL_GameControllerOpen(index);
+					System.Console.WriteLine($"Gamepad added to slot {slot}!");
+					return;
+				}
+			}
+
+			System.Console.WriteLine("Too many gamepads already!");
+		}
+
+		internal void RemoveGamepad(int joystickInstanceID)
+		{
+			for (int slot = 0; slot < MAX_GAMEPADS; slot += 1)
+			{
+				if (joystickInstanceID == gamepads[slot].JoystickInstanceID)
+				{
+					SDL.SDL_GameControllerClose(gamepads[slot].Handle);
+					gamepads[slot].Handle = IntPtr.Zero;
+					System.Console.WriteLine($"Removing gamepad from slot {slot}!");
+					return;
+				}
+			}
+		}
+
 		internal static void OnTextInput(char c)
 		{
 			if (TextInput != null)

src/Input/KeyCode.cs

@@ -1,7 +1,7 @@
 namespace MoonWorks.Input
 {
 	// Enum values are equivalent to the SDL Scancode value.
-	public enum Keycode : int
+	public enum KeyCode : int
 	{
 		Unknown = 0,
 		A = 4,

src/Input/Keyboard.cs

@@ -7,7 +7,12 @@ namespace MoonWorks.Input
 {
 	public class Keyboard
 	{
-		private ButtonState[] Keys { get; }
+		public bool AnyPressed { get; private set; }
+		public KeyboardButton AnyPressedButton { get; private set; }
+
+		public IntPtr State { get; private set; }
+
+		private KeyboardButton[] Keys { get; }
 		private int numKeys;
 
 		private static readonly char[] TextInputCharacters = new char[]
@@ -21,14 +26,14 @@ namespace MoonWorks.Input
 			(char) 22	// Ctrl+V (Paste)
 		};
 
-		private static readonly Dictionary<Keycode, int> TextInputBindings = new Dictionary<Keycode, int>()
+		private static readonly Dictionary<KeyCode, int> TextInputBindings = new Dictionary<KeyCode, int>()
 		{
-			{ Keycode.Home,         0 },
+			{ KeyCode.Home,         0 },
-			{ Keycode.End,          1 },
+			{ KeyCode.End,          1 },
-			{ Keycode.Backspace,    2 },
+			{ KeyCode.Backspace,    2 },
-			{ Keycode.Tab,          3 },
+			{ KeyCode.Tab,          3 },
-			{ Keycode.Return,       4 },
+			{ KeyCode.Return,       4 },
-			{ Keycode.Delete,       5 }
+			{ KeyCode.Delete,       5 }
 			// Ctrl+V is special!
 		};
 
@@ -36,54 +41,69 @@ namespace MoonWorks.Input
 		{
 			SDL.SDL_GetKeyboardState(out numKeys);
 
-			Keys = new ButtonState[numKeys];
+			Keys = new KeyboardButton[numKeys];
-			foreach (Keycode keycode in Enum.GetValues(typeof(Keycode)))
+			foreach (KeyCode keycode in Enum.GetValues(typeof(KeyCode)))
 			{
-				Keys[(int) keycode] = new ButtonState();
+				Keys[(int) keycode] = new KeyboardButton(this, keycode);
 			}
 		}
 
 		internal void Update()
 		{
-			IntPtr keyboardState = SDL.SDL_GetKeyboardState(out _);
+			AnyPressed = false;
 
-			foreach (int keycode in Enum.GetValues(typeof(Keycode)))
+			State = SDL.SDL_GetKeyboardState(out _);
+
+			foreach (int keycode in Enum.GetValues(typeof(KeyCode)))
 			{
-				var keyDown = Marshal.ReadByte(keyboardState, keycode);
+				var button = Keys[keycode];
-				Keys[keycode].Update(Conversions.ByteToBool(keyDown));
+				button.Update();
 
-				if (Conversions.ByteToBool(keyDown))
+				if (button.IsPressed)
 				{
-					if (TextInputBindings.TryGetValue((Keycode) keycode, out var textIndex))
+					if (TextInputBindings.TryGetValue((KeyCode) keycode, out var textIndex))
 					{
 						Inputs.OnTextInput(TextInputCharacters[(textIndex)]);
 					}
-					else if (IsDown(Keycode.LeftControl) && (Keycode) keycode == Keycode.V)
+					else if (IsDown(KeyCode.LeftControl) && (KeyCode) keycode == KeyCode.V)
 					{
 						Inputs.OnTextInput(TextInputCharacters[6]);
 					}
+
+					AnyPressed = true;
+					AnyPressedButton = button;
 				}
 			}
 		}
 
-		public bool IsDown(Keycode keycode)
+		public bool IsDown(KeyCode keycode)
 		{
 			return Keys[(int) keycode].IsDown;
 		}
 
-		public bool IsPressed(Keycode keycode)
+		public bool IsPressed(KeyCode keycode)
 		{
 			return Keys[(int) keycode].IsPressed;
 		}
 
-		public bool IsHeld(Keycode keycode)
+		public bool IsHeld(KeyCode keycode)
 		{
 			return Keys[(int) keycode].IsHeld;
 		}
 
-		public bool IsReleased(Keycode keycode)
+		public bool IsReleased(KeyCode keycode)
 		{
 			return Keys[(int) keycode].IsReleased;
 		}
+
+		public KeyboardButton Button(KeyCode keycode)
+		{
+			return Keys[(int) keycode];
+		}
+
+		public ButtonState ButtonState(KeyCode keycode)
+		{
+			return Keys[(int) keycode].State;
+		}
 	}
 }

src/Input/Mouse.cs

@@ -1,12 +1,13 @@
-using SDL2;
+using System.Collections.Generic;
+using SDL2;
 
 namespace MoonWorks.Input
 {
 	public class Mouse
 	{
-		public ButtonState LeftButton { get; } = new ButtonState();
+		public MouseButton LeftButton { get; }
-		public ButtonState MiddleButton { get; } = new ButtonState();
+		public MouseButton MiddleButton { get; }
-		public ButtonState RightButton { get; } = new ButtonState();
+		public MouseButton RightButton { get; }
 
 		public int X { get; private set; }
 		public int Y { get; private set; }
@@ -15,6 +16,11 @@ namespace MoonWorks.Input
 
 		public int Wheel { get; internal set; }
 
+		public bool AnyPressed { get; private set; }
+		public MouseButton AnyPressedButton { get; private set; }
+
+		public uint ButtonMask { get; private set; }
+
 		private bool relativeMode;
 		public bool RelativeMode
 		{
@@ -30,9 +36,37 @@ namespace MoonWorks.Input
 			}
 		}
 
+		private readonly Dictionary<MouseButtonCode, MouseButton> CodeToButton;
+
+		private IEnumerable<MouseButton> Buttons
+		{
+			get
+			{
+				yield return LeftButton;
+				yield return MiddleButton;
+				yield return RightButton;
+			}
+		}
+
+		public Mouse()
+		{
+			LeftButton = new MouseButton(this, MouseButtonCode.Left, SDL.SDL_BUTTON_LMASK);
+			MiddleButton = new MouseButton(this, MouseButtonCode.Middle, SDL.SDL_BUTTON_MMASK);
+			RightButton = new MouseButton(this, MouseButtonCode.Right, SDL.SDL_BUTTON_RMASK);
+
+			CodeToButton = new Dictionary<MouseButtonCode, MouseButton>
+			{
+				{ MouseButtonCode.Left, LeftButton },
+				{ MouseButtonCode.Right, RightButton },
+				{ MouseButtonCode.Middle, MiddleButton }
+			};
+		}
+
 		internal void Update()
 		{
-			var buttonMask = SDL.SDL_GetMouseState(out var x, out var y);
+			AnyPressed = false;
+
+			ButtonMask = SDL.SDL_GetMouseState(out var x, out var y);
 			var _ = SDL.SDL_GetRelativeMouseState(out var deltaX, out var deltaY);
 
 			X = x;
@@ -40,14 +74,25 @@ namespace MoonWorks.Input
 			DeltaX = deltaX;
 			DeltaY = deltaY;
 
-			LeftButton.Update(IsPressed(buttonMask, SDL.SDL_BUTTON_LMASK));
+			LeftButton.Update();
-			MiddleButton.Update(IsPressed(buttonMask, SDL.SDL_BUTTON_MMASK));
+			MiddleButton.Update();
-			RightButton.Update(IsPressed(buttonMask, SDL.SDL_BUTTON_RMASK));
+			RightButton.Update();
+
+			foreach (var button in Buttons)
+			{
+				button.Update();
+
+				if (button.IsPressed)
+				{
+					AnyPressed = true;
+					AnyPressedButton = button;
+				}
+			}
 		}
 
-		private bool IsPressed(uint buttonMask, uint buttonFlag)
+		public ButtonState ButtonState(MouseButtonCode buttonCode)
 		{
-			return (buttonMask & buttonFlag) != 0;
+			return CodeToButton[buttonCode].State;
 		}
 	}
 }

src/Input/MouseButtonCode.cs

@@ -0,0 +1,9 @@
+namespace MoonWorks.Input
+{
+    public enum MouseButtonCode
+    {
+        Left,
+        Right,
+        Middle
+    }
+}

src/Input/Trigger.cs

@@ -0,0 +1,37 @@
+using MoonWorks.Math;
+using SDL2;
+
+namespace MoonWorks.Input
+{
+	public class Trigger
+	{
+		public Gamepad Parent { get; }
+		public SDL.SDL_GameControllerAxis SDL_Axis;
+
+		public TriggerCode Code { get; }
+
+		/// <summary>
+		/// A trigger value between 0 and 1.
+		/// </summary>
+		public float Value { get; private set; }
+
+		public Trigger(
+			Gamepad parent,
+			TriggerCode code,
+			SDL.SDL_GameControllerAxis sdlAxis
+		) {
+			Parent = parent;
+			Code = code;
+			SDL_Axis = sdlAxis;
+		}
+
+		internal void Update()
+		{
+			Value = MathHelper.Normalize(
+				SDL.SDL_GameControllerGetAxis(Parent.Handle, SDL_Axis),
+				0, short.MaxValue,
+				0, 1
+			);
+		}
+	}
+}

src/Input/TriggerCode.cs

@@ -0,0 +1,9 @@
+namespace MoonWorks.Input
+{
+	// Enum values correspond to SDL GameControllerAxis
+	public enum TriggerCode
+	{
+		Left = 4,
+		Right = 5
+	}
+}

src/Input/VirtualButton.cs

@@ -0,0 +1,34 @@
+namespace MoonWorks.Input
+{
+	public abstract class VirtualButton
+	{
+		public ButtonState State { get; protected set; }
+
+		/// <summary>
+		/// True if the button is pressed or held.
+		/// </summary>
+		public bool IsDown => State.IsDown;
+
+		/// <summary>
+		/// True if the button has been continuously held for more than one frame.
+		/// </summary>
+		public bool IsHeld => State.IsHeld;
+
+		/// <summary>
+		/// True if the button was pressed this exact frame.
+		/// </summary>
+		public bool IsPressed => State.IsPressed;
+
+		/// <summary>
+		/// True if the button is not pressed.
+		/// </summary>
+		public bool IsReleased => State.IsReleased;
+
+		internal virtual void Update()
+		{
+			State = State.Update(CheckPressed());
+		}
+
+		internal abstract bool CheckPressed();
+	}
+}

src/Input/VirtualButtons/AxisButton.cs

@@ -0,0 +1,73 @@
+namespace MoonWorks.Input
+{
+	public class AxisButton : VirtualButton
+	{
+		public Axis Parent { get; }
+		public AxisButtonCode Code { get; }
+
+		private float threshold = 0.9f;
+		public float Threshold
+		{
+			get => threshold;
+			set => threshold = System.Math.Clamp(value, 0, 1);
+		}
+
+		private int Sign;
+
+		internal AxisButton(Axis parent, bool positive)
+		{
+			Parent = parent;
+			Sign = positive ? 1 : -1;
+
+			if (parent.Code == AxisCode.LeftX)
+			{
+				if (positive)
+				{
+					Code = AxisButtonCode.LeftX_Right;
+				}
+				else
+				{
+					Code = AxisButtonCode.LeftX_Left;
+				}
+			}
+			else if (parent.Code == AxisCode.LeftY)
+			{
+				if (positive)
+				{
+					Code = AxisButtonCode.LeftY_Up;
+				}
+				else
+				{
+					Code = AxisButtonCode.LeftY_Down;
+				}
+			}
+			else if (parent.Code == AxisCode.RightX)
+			{
+				if (positive)
+				{
+					Code = AxisButtonCode.RightX_Right;
+				}
+				else
+				{
+					Code = AxisButtonCode.RightX_Left;
+				}
+			}
+			else if (parent.Code == AxisCode.RightY)
+			{
+				if (positive)
+				{
+					Code = AxisButtonCode.RightY_Up;
+				}
+				else
+				{
+					Code = AxisButtonCode.RightY_Down;
+				}
+			}
+		}
+
+		internal override bool CheckPressed()
+		{
+			return Sign * Parent.Value >= threshold;
+		}
+	}
+}

src/Input/VirtualButtons/EmptyButton.cs

@@ -0,0 +1,10 @@
+namespace MoonWorks.Input
+{
+	public class EmptyButton : VirtualButton
+	{
+		internal override bool CheckPressed()
+		{
+			return false;
+		}
+	}
+}

src/Input/VirtualButtons/GamepadButton.cs

@@ -0,0 +1,23 @@
+using SDL2;
+
+namespace MoonWorks.Input
+{
+	public class GamepadButton : VirtualButton
+	{
+		public Gamepad Parent { get; }
+		SDL.SDL_GameControllerButton SDL_Button;
+		public GamepadButtonCode Code { get; }
+
+		internal GamepadButton(Gamepad parent, GamepadButtonCode code, SDL.SDL_GameControllerButton sdlButton)
+		{
+			Parent = parent;
+			Code = code;
+			SDL_Button = sdlButton;
+		}
+
+		internal override bool CheckPressed()
+		{
+			return MoonWorks.Conversions.ByteToBool(SDL.SDL_GameControllerGetButton(Parent.Handle, SDL_Button));
+		}
+	}
+}

src/Input/VirtualButtons/KeyboardButton.cs

@@ -0,0 +1,21 @@
+using System.Runtime.InteropServices;
+
+namespace MoonWorks.Input
+{
+	public class KeyboardButton : VirtualButton
+	{
+		Keyboard Parent;
+		KeyCode KeyCode;
+
+		internal KeyboardButton(Keyboard parent, KeyCode keyCode)
+		{
+			Parent = parent;
+			KeyCode = keyCode;
+		}
+
+		internal override bool CheckPressed()
+		{
+			return Conversions.ByteToBool(Marshal.ReadByte(Parent.State, (int) KeyCode));
+		}
+	}
+}

src/Input/VirtualButtons/MouseButton.cs

@@ -0,0 +1,22 @@
+namespace MoonWorks.Input
+{
+	public class MouseButton : VirtualButton
+	{
+		Mouse Parent;
+		uint ButtonMask;
+
+		public MouseButtonCode Code { get; private set; }
+
+		internal MouseButton(Mouse parent, MouseButtonCode code, uint buttonMask)
+		{
+			Parent = parent;
+			Code = code;
+			ButtonMask = buttonMask;
+		}
+
+		internal override bool CheckPressed()
+		{
+			return (Parent.ButtonMask & ButtonMask) != 0;
+		}
+	}
+}

src/Input/VirtualButtons/TriggerButton.cs

@@ -0,0 +1,25 @@
+namespace MoonWorks.Input
+{
+	public class TriggerButton : VirtualButton
+	{
+		public Trigger Parent { get; }
+		public TriggerCode Code => Parent.Code;
+
+		private float threshold = 0.7f;
+		public float Threshold
+		{
+			get => threshold;
+			set => threshold = System.Math.Clamp(value, 0, 1);
+		}
+
+		internal TriggerButton(Trigger parent)
+		{
+			Parent = parent;
+		}
+
+		internal override bool CheckPressed()
+		{
+			return Parent.Value >= Threshold;
+		}
+	}
+}

src/Math/Fixed/Fix64.cs

@@ -0,0 +1,866 @@
+// This source is heavily borrowed from https://github.com/asik/FixedMath.Net
+
+using System;
+using System.Runtime.CompilerServices;
+
+namespace MoonWorks.Math.Fixed
+{
+	public struct Fix64 : IEquatable<Fix64>, IComparable<Fix64>
+	{
+		private readonly long RawValue;
+
+		const long MAX_VALUE = long.MaxValue;
+		const long MIN_VALUE = long.MinValue;
+		const int FRACTIONAL_PLACES = 32;
+		const int NUM_BITS = 64;
+		const long ONE = 1L << FRACTIONAL_PLACES;
+		const long PI_TIMES_2 = 0x6487ED511;
+		const long PI = 0x3243F6A88;
+		const long PI_OVER_2 = 0x1921FB544;
+
+		public static readonly Fix64 MaxValue = new Fix64(MAX_VALUE);
+		public static readonly Fix64 MinValue = new Fix64(MIN_VALUE);
+		public static readonly Fix64 One = new Fix64(ONE);
+		public static readonly Fix64 Zero = new Fix64(0);
+
+		public static readonly Fix64 Pi = new Fix64(PI);
+		public static readonly Fix64 PiOver2 = new Fix64(PI_OVER_2);
+		public static readonly Fix64 PiOver4 = PiOver2 / new Fix64(2);
+		public static readonly Fix64 PiTimes2 = new Fix64(PI_TIMES_2);
+
+		const int LUT_SIZE = (int)(PI_OVER_2 >> 15);
+		static readonly Fix64 LutInterval = (Fix64)(LUT_SIZE - 1) / PiOver2;
+
+		public bool IsFractional => (RawValue & 0x00000000FFFFFFFF) != 0;
+		public bool IsIntegral => (RawValue & 0x00000000FFFFFFFF) == 0;
+
+		private Fix64(long value)
+		{
+			RawValue = value;
+		}
+
+		public Fix64(int value)
+		{
+			RawValue = value * ONE;
+		}
+
+		/// <summary>
+		/// Create a fractional Fix64 number of the value (numerator / denominator).
+		/// </summary>
+		public static Fix64 FromFraction(int numerator, int denominator)
+		{
+			return new Fix64(numerator) / new Fix64(denominator);
+		}
+
+		/// <summary>
+		/// Gets the fractional component of this Fix64 value.
+		/// </summary>
+		public static Fix64 Fractional(Fix64 number)
+		{
+			return new Fix64(number.RawValue & 0x00000000FFFFFFFF);
+		}
+
+		public static Fix64 Random(System.Random random, int max)
+		{
+			return new Fix64(random.NextInt64(new Fix64(max).RawValue));
+		}
+
+		public static Fix64 Random(System.Random random, Fix64 max)
+		{
+			return new Fix64(random.NextInt64(max.RawValue));
+		}
+
+		public static Fix64 Random(System.Random random, Fix64 min, Fix64 max)
+		{
+			return new Fix64(random.NextInt64(min.RawValue, max.RawValue));
+		}
+
+		// Max should be between 0.0 and 1.0.
+		public static Fix64 RandomFraction(System.Random random, Fix64 max)
+		{
+			long fractionalPart = (max.RawValue & 0x00000000FFFFFFFF);
+			long fractional = random.NextInt64(fractionalPart);
+
+			return new Fix64(fractional);
+		}
+
+		/// <summary>
+		/// Returns an int indicating the sign of a Fix64 number.
+		/// </summary>
+		/// <returns>1 if the value is positive, 0 if it is 0, and -1 if it is negative.</returns>
+		public static int Sign(Fix64 value)
+		{
+			return
+				value.RawValue < 0 ? -1 :
+				value.RawValue > 0 ? 1 :
+				0;
+		}
+
+		/// <summary>
+		/// Returns the absolute value of a Fix64 number.
+		/// </summary>
+		public static Fix64 Abs(Fix64 value)
+		{
+			if (value.RawValue == MIN_VALUE)
+			{
+				return MaxValue;
+			}
+
+			return FastAbs(value);
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private static Fix64 FastAbs(Fix64 value)
+		{
+			// branchless implementation, see http://www.strchr.com/optimized_abs_function
+			var mask = value.RawValue >> 63;
+			return new Fix64((value.RawValue + mask) ^ mask);
+		}
+
+        /// <summary>
+        /// Returns the largest integral value less than or equal to the specified number.
+        /// </summary>
+		public static Fix64 Floor(Fix64 value)
+		{
+			// Zero out the fractional part.
+			return new Fix64((long)((ulong)value.RawValue & 0xFFFFFFFF00000000));
+		}
+
+        /// <summary>
+        /// Returns the smallest integral value that is greater than or equal to the specified number.
+        /// </summary>
+		public static Fix64 Ceiling(Fix64 value)
+		{
+			return value.IsFractional ? Floor(value) + One : value;
+		}
+
+        /// <summary>
+        /// Rounds to the nearest integral value.
+        /// If the value is halfway between an even and an uneven value, returns the even value.
+        /// </summary>
+		public static Fix64 Round(Fix64 value)
+		{
+			var fractionalPart = value.RawValue & 0x00000000FFFFFFFF;
+			var integralPart = Floor(value);
+			if (fractionalPart < 0x80000000)
+			{
+				return integralPart;
+			}
+			if (fractionalPart > 0x80000000)
+			{
+				return integralPart + One;
+			}
+			// if number is halfway between two values, round to the nearest even number
+			// this is the method used by System.Math.Round().
+			return (integralPart.RawValue & ONE) == 0
+					   ? integralPart
+					   : integralPart + One;
+		}
+
+		/// <summary>
+		/// Returns a remainder value as defined by the IEEE remainder method.
+		/// </summary>
+		/// <returns></returns>
+		public static Fix64 IEEERemainder(Fix64 dividend, Fix64 divisor)
+		{
+			//Formula taken from https://docs.microsoft.com/en-us/dotnet/api/system.math.ieeeremainder?view=net-6.0
+			return dividend - (divisor * Round(dividend / divisor));
+		}
+
+		/// <summary>
+		/// Returns the minimum of two given Fix64 values.
+		/// </summary>
+		public static Fix64 Min(Fix64 x, Fix64 y)
+		{
+			return (x < y) ? x : y;
+		}
+
+		/// <summary>
+		/// Returns the maximum of two given Fix64 values.
+		/// </summary>
+		public static Fix64 Max(Fix64 x, Fix64 y)
+		{
+			return (x > y) ? x : y;
+		}
+
+		/// <summary>
+		/// Returns a value that is neither greater than nor less than a given min and max value.
+		/// </summary>
+		public static Fix64 Clamp(Fix64 value, Fix64 min, Fix64 max)
+		{
+			return Fix64.Min(Fix64.Max(value, min), max);
+		}
+
+		public static Fix64 Lerp(Fix64 value1, Fix64 value2, Fix64 amount)
+		{
+			return value1 + (value2 - value1) * amount;
+		}
+
+		/// <summary>
+		/// Rescales a value within a given range to a new range.
+		/// </summary>
+		public static Fix64 Normalize(Fix64 value, Fix64 min, Fix64 max, Fix64 newMin, Fix64 newMax)
+		{
+			return ((value - min) * (newMax - newMin)) / (max - min) + newMin;
+		}
+
+		// Trigonometry functions
+
+		/// <summary>
+		/// Returns the square root of the given Fix64 value.
+		/// </summary>
+		/// <exception cref="ArgumentOutOfRangeException">Throws if x is less than zero.</exception>
+		public static Fix64 Sqrt(Fix64 x)
+		{
+			var xl = x.RawValue;
+			if (xl < 0)
+			{
+				// We cannot represent infinities like Single and Double, and Sqrt is
+				// mathematically undefined for x < 0. So we just throw an exception.
+				throw new ArgumentOutOfRangeException("Negative value passed to Sqrt", "x");
+			}
+
+			var num = (ulong)xl;
+			var result = 0UL;
+
+			// second-to-top bit
+			var bit = 1UL << (NUM_BITS - 2);
+
+			while (bit > num)
+			{
+				bit >>= 2;
+			}
+
+			// The main part is executed twice, in order to avoid
+			// using 128 bit values in computations.
+			for (var i = 0; i < 2; ++i)
+			{
+				// First we get the top 48 bits of the answer.
+				while (bit != 0)
+				{
+					if (num >= result + bit)
+					{
+						num -= result + bit;
+						result = (result >> 1) + bit;
+					}
+					else
+					{
+						result = result >> 1;
+					}
+					bit >>= 2;
+				}
+
+				if (i == 0)
+				{
+					// Then process it again to get the lowest 16 bits.
+					if (num > (1UL << (NUM_BITS / 2)) - 1)
+					{
+						// The remainder 'num' is too large to be shifted left
+						// by 32, so we have to add 1 to result manually and
+						// adjust 'num' accordingly.
+						// num = a - (result + 0.5)^2
+						//       = num + result^2 - (result + 0.5)^2
+						//       = num - result - 0.5
+						num -= result;
+						num = (num << (NUM_BITS / 2)) - 0x80000000UL;
+						result = (result << (NUM_BITS / 2)) + 0x80000000UL;
+					}
+					else
+					{
+						num <<= (NUM_BITS / 2);
+						result <<= (NUM_BITS / 2);
+					}
+
+					bit = 1UL << (NUM_BITS / 2 - 2);
+				}
+			}
+			// Finally, if next bit would have been 1, round the result upwards.
+			if (num > result)
+			{
+				++result;
+			}
+			return new Fix64((long)result);
+		}
+
+		private static long ClampSinValue(long angle, out bool flipHorizontal, out bool flipVertical)
+		{
+			var largePI = 7244019458077122842;
+			// Obtained from ((Fix64)1686629713.065252369824872831112M).m_rawValue
+			// This is (2^29)*PI, where 29 is the largest N such that (2^N)*PI < MaxValue.
+			// The idea is that this number contains way more precision than PI_TIMES_2,
+			// and (((x % (2^29*PI)) % (2^28*PI)) % ... (2^1*PI) = x % (2 * PI)
+			// In practice this gives us an error of about 1,25e-9 in the worst case scenario (Sin(MaxValue))
+			// Whereas simply doing x % PI_TIMES_2 is the 2e-3 range.
+
+			var clamped2Pi = angle;
+			for (int i = 0; i < 29; ++i)
+			{
+				clamped2Pi %= (largePI >> i);
+			}
+			if (angle < 0)
+			{
+				clamped2Pi += PI_TIMES_2;
+			}
+
+			// The LUT contains values for 0 - PiOver2; every other value must be obtained by
+			// vertical or horizontal mirroring
+			flipVertical = clamped2Pi >= PI;
+			// obtain (angle % PI) from (angle % 2PI) - much faster than doing another modulo
+			var clampedPi = clamped2Pi;
+			while (clampedPi >= PI)
+			{
+				clampedPi -= PI;
+			}
+			flipHorizontal = clampedPi >= PI_OVER_2;
+			// obtain (angle % PI_OVER_2) from (angle % PI) - much faster than doing another modulo
+			var clampedPiOver2 = clampedPi;
+			if (clampedPiOver2 >= PI_OVER_2)
+			{
+				clampedPiOver2 -= PI_OVER_2;
+			}
+			return clampedPiOver2;
+		}
+
+		/// <summary>
+		/// Converts degrees to radians.
+		/// </summary>
+		public static Fix64 ToRadians(Fix64 degrees)
+		{
+			return degrees * (Pi / new Fix64(180));
+		}
+
+		/// <summary>
+		/// Converts radians to degrees.
+		/// </summary>
+		public static Fix64 ToDegrees(Fix64 radians)
+		{
+			return radians * (new Fix64(180) / Pi);
+		}
+
+		/// <summary>
+		/// Returns the sine of the specified angle.
+		/// </summary>
+		public static Fix64 Sin(Fix64 x)
+		{
+			var clampedL = ClampSinValue(x.RawValue, out var flipHorizontal, out var flipVertical);
+			var clamped = new Fix64(clampedL);
+
+			// Find the two closest values in the LUT and perform linear interpolation
+			// This is what kills the performance of this function on x86 - x64 is fine though
+			var rawIndex = FastMul(clamped, LutInterval);
+			var roundedIndex = Round(rawIndex);
+			var indexError = FastSub(rawIndex, roundedIndex);
+
+			var nearestValue = new Fix64(Fix64Lut.Sin[flipHorizontal ?
+				Fix64Lut.Sin.Length - 1 - (int)roundedIndex :
+				(int)roundedIndex]);
+			var secondNearestValue = new Fix64(Fix64Lut.Sin[flipHorizontal ?
+				Fix64Lut.Sin.Length - 1 - (int)roundedIndex - Sign(indexError) :
+				(int)roundedIndex + Sign(indexError)]);
+
+			var delta = FastMul(indexError, FastAbs(FastSub(nearestValue, secondNearestValue))).RawValue;
+			var interpolatedValue = nearestValue.RawValue + (flipHorizontal ? -delta : delta);
+			var finalValue = flipVertical ? -interpolatedValue : interpolatedValue;
+			return new Fix64(finalValue);
+		}
+
+		/// <summary>
+		/// Returns the cosine of the specified angle.
+		/// </summary>
+		public static Fix64 Cos(Fix64 x)
+		{
+			var xl = x.RawValue;
+			var rawAngle = xl + (xl > 0 ? -PI - PI_OVER_2 : PI_OVER_2);
+			return Sin(new Fix64(rawAngle));
+		}
+
+		/// <summary>
+		/// Returns the tangent of the specified angle.
+		/// </summary>
+		public static Fix64 Tan(Fix64 x)
+		{
+			var clampedPi = x.RawValue % PI;
+			var flip = false;
+			if (clampedPi < 0)
+			{
+				clampedPi = -clampedPi;
+				flip = true;
+			}
+			if (clampedPi > PI_OVER_2)
+			{
+				flip = !flip;
+				clampedPi = PI_OVER_2 - (clampedPi - PI_OVER_2);
+			}
+
+			var clamped = new Fix64(clampedPi);
+
+			// Find the two closest values in the LUT and perform linear interpolation
+			var rawIndex = FastMul(clamped, LutInterval);
+			var roundedIndex = Round(rawIndex);
+			var indexError = FastSub(rawIndex, roundedIndex);
+
+			var nearestValue = new Fix64(Fix64Lut.Tan[(int)roundedIndex]);
+			var secondNearestValue = new Fix64(Fix64Lut.Tan[(int)roundedIndex + Sign(indexError)]);
+
+			var delta = FastMul(indexError, FastAbs(FastSub(nearestValue, secondNearestValue))).RawValue;
+			var interpolatedValue = nearestValue.RawValue + delta;
+			var finalValue = flip ? -interpolatedValue : interpolatedValue;
+			return new Fix64(finalValue);
+		}
+
+		/// <summary>
+		/// Returns the angle whose tangent is the specified number.
+		/// </summary>
+		public static Fix64 Atan(Fix64 z)
+		{
+			if (z.RawValue == 0) return Zero;
+
+			// Force positive values for argument
+			// Atan(-z) = -Atan(z).
+			var neg = z.RawValue < 0;
+			if (neg)
+			{
+				z = -z;
+			}
+
+			Fix64 result;
+			var two = (Fix64)2;
+			var three = (Fix64)3;
+
+			bool invert = z > One;
+			if (invert) z = One / z;
+
+			result = One;
+			var term = One;
+
+			var zSq = z * z;
+			var zSq2 = zSq * two;
+			var zSqPlusOne = zSq + One;
+			var zSq12 = zSqPlusOne * two;
+			var dividend = zSq2;
+			var divisor = zSqPlusOne * three;
+
+			for (var i = 2; i < 30; ++i)
+			{
+				term *= dividend / divisor;
+				result += term;
+
+				dividend += zSq2;
+				divisor += zSq12;
+
+				if (term.RawValue == 0) break;
+			}
+
+			result = result * z / zSqPlusOne;
+
+			if (invert)
+			{
+				result = PiOver2 - result;
+			}
+
+			if (neg)
+			{
+				result = -result;
+			}
+			return result;
+		}
+
+		/// <summary>
+		/// Returns the angle whose tangent is the quotient of two specified numbers.
+		/// </summary>
+		public static Fix64 Atan2(Fix64 y, Fix64 x)
+		{
+			var yl = y.RawValue;
+			var xl = x.RawValue;
+			if (xl == 0)
+			{
+				if (yl > 0)
+				{
+					return PiOver2;
+				}
+				if (yl == 0)
+				{
+					return Zero;
+				}
+				return -PiOver2;
+			}
+			Fix64 atan;
+			var z = y / x;
+
+			// Deal with overflow
+			if (One + Fix64.FromFraction(28, 100) * z * z == MaxValue)
+			{
+				return y < Zero ? -PiOver2 : PiOver2;
+			}
+
+			if (Abs(z) < One)
+			{
+				atan = z / (One + Fix64.FromFraction(28, 100) * z * z);
+				if (xl < 0)
+				{
+					if (yl < 0)
+					{
+						return atan - Pi;
+					}
+					return atan + Pi;
+				}
+			}
+			else
+			{
+				atan = PiOver2 - z / (z * z + Fix64.FromFraction(28, 100));
+				if (yl < 0)
+				{
+					return atan - Pi;
+				}
+			}
+			return atan;
+		}
+
+		// Operators
+
+		public static Fix64 operator +(Fix64 x, Fix64 y)
+		{
+			var xl = x.RawValue;
+			var yl = y.RawValue;
+			var sum = xl + yl;
+			// if signs of operands are equal and signs of sum and x are different
+			if (((~(xl ^ yl) & (xl ^ sum)) & MIN_VALUE) != 0)
+			{
+				sum = xl > 0 ? MAX_VALUE : MIN_VALUE;
+			}
+			return new Fix64(sum);
+		}
+
+		public static Fix64 operator -(Fix64 x, Fix64 y)
+		{
+			var xl = x.RawValue;
+			var yl = y.RawValue;
+			var diff = xl - yl;
+			// if signs of operands are different and signs of sum and x are different
+			if ((((xl ^ yl) & (xl ^ diff)) & MIN_VALUE) != 0)
+			{
+				diff = xl < 0 ? MIN_VALUE : MAX_VALUE;
+			}
+			return new Fix64(diff);
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private static Fix64 FastSub(Fix64 x, Fix64 y)
+		{
+			return new Fix64(x.RawValue - y.RawValue);
+		}
+
+		private static long AddOverflowHelper(long x, long y, ref bool overflow)
+		{
+			var sum = x + y;
+			// x + y overflows if sign(x) ^ sign(y) != sign(sum)
+			overflow |= ((x ^ y ^ sum) & MIN_VALUE) != 0;
+			return sum;
+		}
+
+		public static Fix64 operator *(Fix64 x, Fix64 y)
+		{
+			var xl = x.RawValue;
+			var yl = y.RawValue;
+
+			var xlo = (ulong)(xl & 0x00000000FFFFFFFF);
+			var xhi = xl >> FRACTIONAL_PLACES;
+			var ylo = (ulong)(yl & 0x00000000FFFFFFFF);
+			var yhi = yl >> FRACTIONAL_PLACES;
+
+			var lolo = xlo * ylo;
+			var lohi = (long)xlo * yhi;
+			var hilo = xhi * (long)ylo;
+			var hihi = xhi * yhi;
+
+			var loResult = lolo >> FRACTIONAL_PLACES;
+			var midResult1 = lohi;
+			var midResult2 = hilo;
+			var hiResult = hihi << FRACTIONAL_PLACES;
+
+			bool overflow = false;
+			var sum = AddOverflowHelper((long)loResult, midResult1, ref overflow);
+			sum = AddOverflowHelper(sum, midResult2, ref overflow);
+			sum = AddOverflowHelper(sum, hiResult, ref overflow);
+
+			bool opSignsEqual = ((xl ^ yl) & MIN_VALUE) == 0;
+
+			// if signs of operands are equal and sign of result is negative,
+			// then multiplication overflowed positively
+			// the reverse is also true
+			if (opSignsEqual)
+			{
+				if (sum < 0 || (overflow && xl > 0))
+				{
+					return MaxValue;
+				}
+			}
+			else
+			{
+				if (sum > 0)
+				{
+					return MinValue;
+				}
+			}
+
+			// if the top 32 bits of hihi (unused in the result) are neither all 0s or 1s,
+			// then this means the result overflowed.
+			var topCarry = hihi >> FRACTIONAL_PLACES;
+			if (topCarry != 0 && topCarry != -1 /*&& xl != -17 && yl != -17*/)
+			{
+				return opSignsEqual ? MaxValue : MinValue;
+			}
+
+			// If signs differ, both operands' magnitudes are greater than 1,
+			// and the result is greater than the negative operand, then there was negative overflow.
+			if (!opSignsEqual)
+			{
+				long posOp, negOp;
+				if (xl > yl)
+				{
+					posOp = xl;
+					negOp = yl;
+				}
+				else
+				{
+					posOp = yl;
+					negOp = xl;
+				}
+				if (sum > negOp && negOp < -ONE && posOp > ONE)
+				{
+					return MinValue;
+				}
+			}
+
+			return new Fix64(sum);
+		}
+
+		private static Fix64 FastMul(Fix64 x, Fix64 y)
+		{
+			var xl = x.RawValue;
+			var yl = y.RawValue;
+
+			var xlo = (ulong)(xl & 0x00000000FFFFFFFF);
+			var xhi = xl >> FRACTIONAL_PLACES;
+			var ylo = (ulong)(yl & 0x00000000FFFFFFFF);
+			var yhi = yl >> FRACTIONAL_PLACES;
+
+			var lolo = xlo * ylo;
+			var lohi = (long)xlo * yhi;
+			var hilo = xhi * (long)ylo;
+			var hihi = xhi * yhi;
+
+			var loResult = lolo >> FRACTIONAL_PLACES;
+			var midResult1 = lohi;
+			var midResult2 = hilo;
+			var hiResult = hihi << FRACTIONAL_PLACES;
+
+			var sum = (long)loResult + midResult1 + midResult2 + hiResult;
+			return new Fix64(sum);
+		}
+
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private static int CountLeadingZeroes(ulong x)
+		{
+			int result = 0;
+			while ((x & 0xF000000000000000) == 0) { result += 4; x <<= 4; }
+			while ((x & 0x8000000000000000) == 0) { result += 1; x <<= 1; }
+			return result;
+		}
+
+		public static Fix64 operator /(Fix64 x, Fix64 y)
+		{
+			var xl = x.RawValue;
+			var yl = y.RawValue;
+
+			if (yl == 0)
+			{
+				throw new DivideByZeroException();
+			}
+
+			var remainder = (ulong)(xl >= 0 ? xl : -xl);
+			var divider = (ulong)(yl >= 0 ? yl : -yl);
+			var quotient = 0UL;
+			var bitPos = NUM_BITS / 2 + 1;
+
+
+			// If the divider is divisible by 2^n, take advantage of it.
+			while ((divider & 0xF) == 0 && bitPos >= 4)
+			{
+				divider >>= 4;
+				bitPos -= 4;
+			}
+
+			while (remainder != 0 && bitPos >= 0)
+			{
+				int shift = CountLeadingZeroes(remainder);
+				if (shift > bitPos)
+				{
+					shift = bitPos;
+				}
+				remainder <<= shift;
+				bitPos -= shift;
+
+				var div = remainder / divider;
+				remainder = remainder % divider;
+				quotient += div << bitPos;
+
+				// Detect overflow
+				if ((div & ~(0xFFFFFFFFFFFFFFFF >> bitPos)) != 0)
+				{
+					return ((xl ^ yl) & MIN_VALUE) == 0 ? MaxValue : MinValue;
+				}
+
+				remainder <<= 1;
+				--bitPos;
+			}
+
+			// rounding
+			++quotient;
+			var result = (long)(quotient >> 1);
+			if (((xl ^ yl) & MIN_VALUE) != 0)
+			{
+				result = -result;
+			}
+
+			return new Fix64(result);
+		}
+
+		public static Fix64 operator %(Fix64 x, Fix64 y)
+		{
+			return new Fix64(
+				x.RawValue == MIN_VALUE & y.RawValue == -1 ?
+				0 :
+				x.RawValue % y.RawValue);
+		}
+
+		public static Fix64 operator -(Fix64 x)
+		{
+			return x.RawValue == MIN_VALUE ? MaxValue : new Fix64(-x.RawValue);
+		}
+
+		public static bool operator ==(Fix64 x, Fix64 y)
+		{
+			return x.RawValue == y.RawValue;
+		}
+
+		public static bool operator !=(Fix64 x, Fix64 y)
+		{
+			return x.RawValue != y.RawValue;
+		}
+
+		public static bool operator >(Fix64 x, Fix64 y)
+		{
+			return x.RawValue > y.RawValue;
+		}
+
+		public static bool operator <(Fix64 x, Fix64 y)
+		{
+			return x.RawValue < y.RawValue;
+		}
+
+		public static bool operator >(Fix64 x, int y)
+		{
+			return x > ((Fix64) y);
+		}
+
+		public static bool operator <(Fix64 x, int y)
+		{
+			return x < ((Fix64) y);
+		}
+
+		public static bool operator >=(Fix64 x, Fix64 y)
+		{
+			return x.RawValue >= y.RawValue;
+		}
+
+		public static bool operator <=(Fix64 x, Fix64 y)
+		{
+			return x.RawValue <= y.RawValue;
+		}
+
+		public static bool operator >=(Fix64 x, int y)
+		{
+			return x >= ((Fix64) y);
+		}
+
+		public static bool operator <=(Fix64 x, int y)
+		{
+			return x <= ((Fix64) y);
+		}
+
+		// Casting
+
+		public static explicit operator Fix64(long value)
+		{
+			return new Fix64(value * ONE);
+		}
+
+		public static explicit operator long(Fix64 value)
+		{
+			return value.RawValue >> FRACTIONAL_PLACES;
+		}
+
+		public static explicit operator Fix64(float value)
+		{
+			return new Fix64((long)(value * ONE));
+		}
+
+		public static explicit operator float(Fix64 value)
+		{
+			return (float)value.RawValue / ONE;
+		}
+
+		public static explicit operator Fix64(double value)
+		{
+			return new Fix64((long)(value * ONE));
+		}
+
+		public static explicit operator double(Fix64 value)
+		{
+			return (double)value.RawValue / ONE;
+		}
+
+		public static explicit operator Fix64(decimal value)
+		{
+			return new Fix64((long)(value * ONE));
+		}
+
+		public static explicit operator decimal(Fix64 value)
+		{
+			return (decimal)value.RawValue / ONE;
+		}
+
+		public int CompareTo(Fix64 other)
+		{
+			return RawValue.CompareTo(other.RawValue);
+		}
+
+		public override bool Equals(object obj)
+		{
+			return obj is Fix64 fix && RawValue == fix.RawValue;
+		}
+
+		public bool Equals(Fix64 other)
+		{
+			return RawValue == other.RawValue;
+		}
+
+		public override int GetHashCode()
+		{
+			return RawValue.GetHashCode();
+		}
+
+		// FIXME: can we avoid this cast?
+		public override string ToString()
+		{
+			// Up to 10 decimal places
+			return ((decimal)this).ToString("0.##########");
+		}
+
+		public string ToString(System.Globalization.CultureInfo ci)
+		{
+			return ((decimal) this).ToString("0.##########", ci);
+		}
+	}
+}

src/Math/Fixed/Matrix3x2.cs

@@ -0,0 +1,846 @@
+/* MoonWorks - Game Development Framework
+ * Copyright 2022 Evan Hemsley
+ */
+
+/* Derived from code by Microsoft.
+ * Released under the MIT license.
+ * See microsoft.LICENSE for details.
+ */
+
+using System;
+using System.Globalization;
+
+namespace MoonWorks.Math.Fixed
+{
+	/// <summary>
+	/// A structure encapsulating a 3x2 fixed point matrix.
+	/// </summary>
+	public struct Matrix3x2 : IEquatable<Matrix3x2>
+	{
+		#region Public Fields
+		/// <summary>
+		/// The first element of the first row
+		/// </summary>
+		public Fix64 M11;
+		/// <summary>
+		/// The second element of the first row
+		/// </summary>
+		public Fix64 M12;
+		/// <summary>
+		/// The first element of the second row
+		/// </summary>
+		public Fix64 M21;
+		/// <summary>
+		/// The second element of the second row
+		/// </summary>
+		public Fix64 M22;
+		/// <summary>
+		/// The first element of the third row
+		/// </summary>
+		public Fix64 M31;
+		/// <summary>
+		/// The second element of the third row
+		/// </summary>
+		public Fix64 M32;
+		#endregion Public Fields
+
+		private static readonly Matrix3x2 _identity = new Matrix3x2
+		(
+			1, 0,
+			0, 1,
+			0, 0
+		);
+
+		private static readonly Fix64 RotationEpsilon = Fix64.FromFraction(1, 1000) * (Fix64.Pi / new Fix64(180));
+
+		/// <summary>
+		/// Returns the multiplicative identity matrix.
+		/// </summary>
+		public static Matrix3x2 Identity
+		{
+			get { return _identity; }
+		}
+
+		/// <summary>
+		/// Returns whether the matrix is the identity matrix.
+		/// </summary>
+		public bool IsIdentity
+		{
+			get
+			{
+				return  M11 == Fix64.One && M22 == Fix64.One && // Check diagonal element first for early out.
+                        M12 == Fix64.Zero &&
+					    M21 == Fix64.Zero &&
+					    M31 == Fix64.Zero && M32 == Fix64.Zero;
+			}
+		}
+
+		/// <summary>
+		/// Gets or sets the translation component of this matrix.
+		/// </summary>
+		public Vector2 Translation
+		{
+			get
+			{
+				return new Vector2(M31, M32);
+			}
+
+			set
+			{
+				M31 = value.X;
+				M32 = value.Y;
+			}
+		}
+
+		/// <summary>
+		/// Constructs a FixMatrix3x2 from the given components.
+		/// </summary>
+		public Matrix3x2(Fix64 m11, Fix64 m12,
+						 Fix64 m21, Fix64 m22,
+						 Fix64 m31, Fix64 m32)
+		{
+			M11 = m11;
+			M12 = m12;
+			M21 = m21;
+			M22 = m22;
+			M31 = m31;
+			M32 = m32;
+		}
+
+        public Matrix3x2(int m11, int m12, int m21, int m22, int m31, int m32)
+        {
+            M11 = new Fix64(m11);
+			M12 = new Fix64(m12);
+			M21 = new Fix64(m21);
+			M22 = new Fix64(m22);
+			M31 = new Fix64(m31);
+			M32 = new Fix64(m32);
+        }
+
+		/// <summary>
+		/// Creates a translation matrix from the given vector.
+		/// </summary>
+		/// <param name="position">The translation position.</param>
+		/// <returns>A translation matrix.</returns>
+		public static Matrix3x2 CreateTranslation(Vector2 position)
+		{
+			Matrix3x2 result;
+
+			result.M11 = Fix64.One;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = Fix64.One;
+
+			result.M31 = position.X;
+			result.M32 = position.Y;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a translation matrix from the given X and Y components.
+		/// </summary>
+		/// <param name="xPosition">The X position.</param>
+		/// <param name="yPosition">The Y position.</param>
+		/// <returns>A translation matrix.</returns>
+		public static Matrix3x2 CreateTranslation(Fix64 xPosition, Fix64 yPosition)
+		{
+			Matrix3x2 result;
+
+			result.M11 = Fix64.One;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = Fix64.One;
+
+			result.M31 = xPosition;
+			result.M32 = yPosition;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a scale matrix from the given X and Y components.
+		/// </summary>
+		/// <param name="xScale">Value to scale by on the X-axis.</param>
+		/// <param name="yScale">Value to scale by on the Y-axis.</param>
+		/// <returns>A scaling matrix.</returns>
+		public static Matrix3x2 CreateScale(Fix64 xScale, Fix64 yScale)
+		{
+			Matrix3x2 result;
+
+			result.M11 = xScale;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = yScale;
+			result.M31 = Fix64.Zero;
+			result.M32 = Fix64.Zero;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a scale matrix that is offset by a given center point.
+		/// </summary>
+		/// <param name="xScale">Value to scale by on the X-axis.</param>
+		/// <param name="yScale">Value to scale by on the Y-axis.</param>
+		/// <param name="centerPoint">The center point.</param>
+		/// <returns>A scaling matrix.</returns>
+		public static Matrix3x2 CreateScale(Fix64 xScale, Fix64 yScale, Vector2 centerPoint)
+		{
+			Matrix3x2 result;
+
+			Fix64 tx = centerPoint.X * (Fix64.One - xScale);
+			Fix64 ty = centerPoint.Y * (Fix64.One - yScale);
+
+			result.M11 = xScale;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = yScale;
+			result.M31 = tx;
+			result.M32 = ty;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a scale matrix from the given vector scale.
+		/// </summary>
+		/// <param name="scales">The scale to use.</param>
+		/// <returns>A scaling matrix.</returns>
+		public static Matrix3x2 CreateScale(Vector2 scales)
+		{
+			Matrix3x2 result;
+
+			result.M11 = scales.X;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = scales.Y;
+			result.M31 = Fix64.Zero;
+			result.M32 = Fix64.Zero;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a scale matrix from the given vector scale with an offset from the given center point.
+		/// </summary>
+		/// <param name="scales">The scale to use.</param>
+		/// <param name="centerPoint">The center offset.</param>
+		/// <returns>A scaling matrix.</returns>
+		public static Matrix3x2 CreateScale(Vector2 scales, Vector2 centerPoint)
+		{
+			Matrix3x2 result;
+
+			Fix64 tx = centerPoint.X * (Fix64.One - scales.X);
+			Fix64 ty = centerPoint.Y * (Fix64.One - scales.Y);
+
+			result.M11 = scales.X;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = scales.Y;
+			result.M31 = tx;
+			result.M32 = ty;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a scale matrix that scales uniformly with the given scale.
+		/// </summary>
+		/// <param name="scale">The uniform scale to use.</param>
+		/// <returns>A scaling matrix.</returns>
+		public static Matrix3x2 CreateScale(Fix64 scale)
+		{
+			Matrix3x2 result;
+
+			result.M11 = scale;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = scale;
+			result.M31 = Fix64.Zero;
+			result.M32 = Fix64.Zero;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a scale matrix that scales uniformly with the given scale with an offset from the given center.
+		/// </summary>
+		/// <param name="scale">The uniform scale to use.</param>
+		/// <param name="centerPoint">The center offset.</param>
+		/// <returns>A scaling matrix.</returns>
+		public static Matrix3x2 CreateScale(Fix64 scale, Vector2 centerPoint)
+		{
+			Matrix3x2 result;
+
+			Fix64 tx = centerPoint.X * (Fix64.One - scale);
+			Fix64 ty = centerPoint.Y * (Fix64.One - scale);
+
+			result.M11 = scale;
+			result.M12 = Fix64.Zero;
+			result.M21 = Fix64.Zero;
+			result.M22 = scale;
+			result.M31 = tx;
+			result.M32 = ty;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a skew matrix from the given angles in radians.
+		/// </summary>
+		/// <param name="radiansX">The X angle, in radians.</param>
+		/// <param name="radiansY">The Y angle, in radians.</param>
+		/// <returns>A skew matrix.</returns>
+		public static Matrix3x2 CreateSkew(Fix64 radiansX, Fix64 radiansY)
+		{
+			Matrix3x2 result;
+
+			Fix64 xTan = (Fix64) Fix64.Tan(radiansX);
+			Fix64 yTan = (Fix64) Fix64.Tan(radiansY);
+
+			result.M11 = Fix64.One;
+			result.M12 = yTan;
+			result.M21 = xTan;
+			result.M22 = Fix64.One;
+			result.M31 = Fix64.Zero;
+			result.M32 = Fix64.Zero;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a skew matrix from the given angles in radians and a center point.
+		/// </summary>
+		/// <param name="radiansX">The X angle, in radians.</param>
+		/// <param name="radiansY">The Y angle, in radians.</param>
+		/// <param name="centerPoint">The center point.</param>
+		/// <returns>A skew matrix.</returns>
+		public static Matrix3x2 CreateSkew(Fix64 radiansX, Fix64 radiansY, Vector2 centerPoint)
+		{
+			Matrix3x2 result;
+
+			Fix64 xTan = (Fix64) Fix64.Tan(radiansX);
+			Fix64 yTan = (Fix64) Fix64.Tan(radiansY);
+
+			Fix64 tx = -centerPoint.Y * xTan;
+			Fix64 ty = -centerPoint.X * yTan;
+
+			result.M11 = Fix64.One;
+			result.M12 = yTan;
+			result.M21 = xTan;
+			result.M22 = Fix64.One;
+			result.M31 = tx;
+			result.M32 = ty;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a rotation matrix using the given rotation in radians.
+		/// </summary>
+		/// <param name="radians">The amount of rotation, in radians.</param>
+		/// <returns>A rotation matrix.</returns>
+		public static Matrix3x2 CreateRotation(Fix64 radians)
+		{
+			Matrix3x2 result;
+
+			radians = Fix64.IEEERemainder(radians, Fix64.PiTimes2);
+
+			Fix64 c, s;
+
+			if (radians > -RotationEpsilon && radians < RotationEpsilon)
+			{
+				// Exact case for zero rotation.
+				c = Fix64.One;
+				s = Fix64.Zero;
+			}
+			else if (radians > Fix64.PiOver2 - RotationEpsilon && radians < Fix64.PiOver2 + RotationEpsilon)
+			{
+				// Exact case for 90 degree rotation.
+				c = Fix64.Zero;
+				s = Fix64.One;
+			}
+			else if (radians < -Fix64.Pi + RotationEpsilon || radians > Fix64.Pi - RotationEpsilon)
+			{
+				// Exact case for 180 degree rotation.
+				c = -Fix64.One;
+				s = Fix64.Zero;
+			}
+			else if (radians > -Fix64.PiOver2 - RotationEpsilon && radians < -Fix64.PiOver2 + RotationEpsilon)
+			{
+				// Exact case for 270 degree rotation.
+				c = Fix64.Zero;
+				s = -Fix64.One;
+			}
+			else
+			{
+				// Arbitrary rotation.
+				c = Fix64.Cos(radians);
+				s = Fix64.Sin(radians);
+			}
+
+			// [  c  s ]
+			// [ -s  c ]
+			// [  0  0 ]
+			result.M11 = c;
+			result.M12 = s;
+			result.M21 = -s;
+			result.M22 = c;
+			result.M31 = Fix64.Zero;
+			result.M32 = Fix64.Zero;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a rotation matrix using the given rotation in radians and a center point.
+		/// </summary>
+		/// <param name="radians">The amount of rotation, in radians.</param>
+		/// <param name="centerPoint">The center point.</param>
+		/// <returns>A rotation matrix.</returns>
+		public static Matrix3x2 CreateRotation(Fix64 radians, Vector2 centerPoint)
+		{
+			Matrix3x2 result;
+
+			radians = Fix64.IEEERemainder(radians, Fix64.PiTimes2);
+
+			Fix64 c, s;
+
+			if (radians > -RotationEpsilon && radians < RotationEpsilon)
+			{
+				// Exact case for zero rotation.
+				c = Fix64.One;
+				s = Fix64.Zero;
+			}
+			else if (radians > Fix64.PiOver2 - RotationEpsilon && radians < Fix64.PiOver2 + RotationEpsilon)
+			{
+				// Exact case for 90 degree rotation.
+				c = Fix64.Zero;
+				s = Fix64.One;
+			}
+			else if (radians < -Fix64.Pi + RotationEpsilon || radians > Fix64.Pi - RotationEpsilon)
+			{
+				// Exact case for 180 degree rotation.
+				c = -Fix64.One;
+				s = Fix64.Zero;
+			}
+			else if (radians > -Fix64.PiOver2 - RotationEpsilon && radians < -Fix64.PiOver2 + RotationEpsilon)
+			{
+				// Exact case for 270 degree rotation.
+				c = Fix64.Zero;
+				s = -Fix64.One;
+			}
+			else
+			{
+				// Arbitrary rotation.
+				c = (Fix64) Fix64.Cos(radians);
+				s = (Fix64) Fix64.Sin(radians);
+			}
+
+			Fix64 x = centerPoint.X * (Fix64.One - c) + centerPoint.Y * s;
+			Fix64 y = centerPoint.Y * (Fix64.One - c) - centerPoint.X * s;
+
+			// [  c  s ]
+			// [ -s  c ]
+			// [  x  y ]
+			result.M11 = c;
+			result.M12 = s;
+			result.M21 = -s;
+			result.M22 = c;
+			result.M31 = x;
+			result.M32 = y;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Calculates the determinant for this matrix.
+		/// The determinant is calculated by expanding the matrix with a third column whose values are (0,0,1).
+		/// </summary>
+		/// <returns>The determinant.</returns>
+		public Fix64 GetDeterminant()
+		{
+			// There isn't actually any such thing as a determinant for a non-square matrix,
+			// but this 3x2 type is really just an optimization of a 3x3 where we happen to
+			// know the rightmost column is always (0, 0, 1). So we expand to 3x3 format:
+			//
+			//  [ M11, M12, 0 ]
+			//  [ M21, M22, 0 ]
+			//  [ M31, M32, 1 ]
+			//
+			// Sum the diagonal products:
+			//  (M11 * M22 * 1) + (M12 * 0 * M31) + (0 * M21 * M32)
+			//
+			// Subtract the opposite diagonal products:
+			//  (M31 * M22 * 0) + (M32 * 0 * M11) + (1 * M21 * M12)
+			//
+			// Collapse out the constants and oh look, this is just a 2x2 determinant!
+
+			return (M11 * M22) - (M21 * M12);
+		}
+
+		/// <summary>
+		/// Attempts to invert the given matrix. If the operation succeeds, the inverted matrix is stored in the result parameter.
+		/// </summary>
+		/// <param name="matrix">The source matrix.</param>
+		/// <param name="result">The output matrix.</param>
+		/// <returns>True if the operation succeeded, False otherwise.</returns>
+		public static bool Invert(Matrix3x2 matrix, out Matrix3x2 result)
+		{
+			Fix64 det = (matrix.M11 * matrix.M22) - (matrix.M21 * matrix.M12);
+
+			if (Fix64.Abs(det) == Fix64.Zero)
+			{
+				result = new Matrix3x2(Fix64.Zero, Fix64.Zero, Fix64.Zero, Fix64.Zero, Fix64.Zero, Fix64.Zero);
+				return false;
+			}
+
+			Fix64 invDet = Fix64.One / det;
+
+			result.M11 = matrix.M22 * invDet;
+			result.M12 = -matrix.M12 * invDet;
+			result.M21 = -matrix.M21 * invDet;
+			result.M22 = matrix.M11 * invDet;
+			result.M31 = (matrix.M21 * matrix.M32 - matrix.M31 * matrix.M22) * invDet;
+			result.M32 = (matrix.M31 * matrix.M12 - matrix.M11 * matrix.M32) * invDet;
+
+			return true;
+		}
+
+		/// <summary>
+		/// Linearly interpolates from matrix1 to matrix2, based on the third parameter.
+		/// </summary>
+		/// <param name="matrix1">The first source matrix.</param>
+		/// <param name="matrix2">The second source matrix.</param>
+		/// <param name="amount">The relative weighting of matrix2.</param>
+		/// <returns>The interpolated matrix.</returns>
+		public static Matrix3x2 Lerp(Matrix3x2 matrix1, Matrix3x2 matrix2, Fix64 amount)
+		{
+			Matrix3x2 result;
+
+			// First row
+			result.M11 = matrix1.M11 + (matrix2.M11 - matrix1.M11) * amount;
+			result.M12 = matrix1.M12 + (matrix2.M12 - matrix1.M12) * amount;
+
+			// Second row
+			result.M21 = matrix1.M21 + (matrix2.M21 - matrix1.M21) * amount;
+			result.M22 = matrix1.M22 + (matrix2.M22 - matrix1.M22) * amount;
+
+			// Third row
+			result.M31 = matrix1.M31 + (matrix2.M31 - matrix1.M31) * amount;
+			result.M32 = matrix1.M32 + (matrix2.M32 - matrix1.M32) * amount;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Negates the given matrix by multiplying all values by -1.
+		/// </summary>
+		/// <param name="value">The source matrix.</param>
+		/// <returns>The negated matrix.</returns>
+		public static Matrix3x2 Negate(Matrix3x2 value)
+		{
+			Matrix3x2 result;
+
+			result.M11 = -value.M11;
+			result.M12 = -value.M12;
+			result.M21 = -value.M21;
+			result.M22 = -value.M22;
+			result.M31 = -value.M31;
+			result.M32 = -value.M32;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Adds each matrix element in value1 with its corresponding element in value2.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>The matrix containing the summed values.</returns>
+		public static Matrix3x2 Add(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			Matrix3x2 result;
+
+			result.M11 = value1.M11 + value2.M11;
+			result.M12 = value1.M12 + value2.M12;
+			result.M21 = value1.M21 + value2.M21;
+			result.M22 = value1.M22 + value2.M22;
+			result.M31 = value1.M31 + value2.M31;
+			result.M32 = value1.M32 + value2.M32;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Subtracts each matrix element in value2 from its corresponding element in value1.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>The matrix containing the resulting values.</returns>
+		public static Matrix3x2 Subtract(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			Matrix3x2 result;
+
+			result.M11 = value1.M11 - value2.M11;
+			result.M12 = value1.M12 - value2.M12;
+			result.M21 = value1.M21 - value2.M21;
+			result.M22 = value1.M22 - value2.M22;
+			result.M31 = value1.M31 - value2.M31;
+			result.M32 = value1.M32 - value2.M32;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Multiplies two matrices together and returns the resulting matrix.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>The product matrix.</returns>
+		public static Matrix3x2 Multiply(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			Matrix3x2 result;
+
+			// First row
+			result.M11 = value1.M11 * value2.M11 + value1.M12 * value2.M21;
+			result.M12 = value1.M11 * value2.M12 + value1.M12 * value2.M22;
+
+			// Second row
+			result.M21 = value1.M21 * value2.M11 + value1.M22 * value2.M21;
+			result.M22 = value1.M21 * value2.M12 + value1.M22 * value2.M22;
+
+			// Third row
+			result.M31 = value1.M31 * value2.M11 + value1.M32 * value2.M21 + value2.M31;
+			result.M32 = value1.M31 * value2.M12 + value1.M32 * value2.M22 + value2.M32;
+
+			return result;
+		}
+
+		public Matrix4x4 ToMatrix4x4()
+		{
+			return new Matrix4x4(
+				M11, M12, Fix64.Zero, Fix64.Zero,
+				M21, M22, Fix64.Zero, Fix64.Zero,
+				Fix64.Zero, Fix64.Zero, Fix64.One, Fix64.Zero,
+				M31, M32, Fix64.Zero, Fix64.One
+			);
+		}
+
+		/// <summary>
+		/// Scales all elements in a matrix by the given scalar factor.
+		/// </summary>
+		/// <param name="value1">The source matrix.</param>
+		/// <param name="value2">The scaling value to use.</param>
+		/// <returns>The resulting matrix.</returns>
+		public static Matrix3x2 Multiply(Matrix3x2 value1, Fix64 value2)
+		{
+			Matrix3x2 result;
+
+			result.M11 = value1.M11 * value2;
+			result.M12 = value1.M12 * value2;
+			result.M21 = value1.M21 * value2;
+			result.M22 = value1.M22 * value2;
+			result.M31 = value1.M31 * value2;
+			result.M32 = value1.M32 * value2;
+
+			return result;
+		}
+
+		/// <summary>
+		/// Negates the given matrix by multiplying all values by -1.
+		/// </summary>
+		/// <param name="value">The source matrix.</param>
+		/// <returns>The negated matrix.</returns>
+		public static Matrix3x2 operator -(Matrix3x2 value)
+		{
+			Matrix3x2 m;
+
+			m.M11 = -value.M11;
+			m.M12 = -value.M12;
+			m.M21 = -value.M21;
+			m.M22 = -value.M22;
+			m.M31 = -value.M31;
+			m.M32 = -value.M32;
+
+			return m;
+		}
+
+		/// <summary>
+		/// Adds each matrix element in value1 with its corresponding element in value2.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>The matrix containing the summed values.</returns>
+		public static Matrix3x2 operator +(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			Matrix3x2 m;
+
+			m.M11 = value1.M11 + value2.M11;
+			m.M12 = value1.M12 + value2.M12;
+			m.M21 = value1.M21 + value2.M21;
+			m.M22 = value1.M22 + value2.M22;
+			m.M31 = value1.M31 + value2.M31;
+			m.M32 = value1.M32 + value2.M32;
+
+			return m;
+		}
+
+		/// <summary>
+		/// Subtracts each matrix element in value2 from its corresponding element in value1.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>The matrix containing the resulting values.</returns>
+		public static Matrix3x2 operator -(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			Matrix3x2 m;
+
+			m.M11 = value1.M11 - value2.M11;
+			m.M12 = value1.M12 - value2.M12;
+			m.M21 = value1.M21 - value2.M21;
+			m.M22 = value1.M22 - value2.M22;
+			m.M31 = value1.M31 - value2.M31;
+			m.M32 = value1.M32 - value2.M32;
+
+			return m;
+		}
+
+		/// <summary>
+		/// Multiplies two matrices together and returns the resulting matrix.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>The product matrix.</returns>
+		public static Matrix3x2 operator *(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			Matrix3x2 m;
+
+			// First row
+			m.M11 = value1.M11 * value2.M11 + value1.M12 * value2.M21;
+			m.M12 = value1.M11 * value2.M12 + value1.M12 * value2.M22;
+
+			// Second row
+			m.M21 = value1.M21 * value2.M11 + value1.M22 * value2.M21;
+			m.M22 = value1.M21 * value2.M12 + value1.M22 * value2.M22;
+
+			// Third row
+			m.M31 = value1.M31 * value2.M11 + value1.M32 * value2.M21 + value2.M31;
+			m.M32 = value1.M31 * value2.M12 + value1.M32 * value2.M22 + value2.M32;
+
+			return m;
+		}
+
+		/// <summary>
+		/// Scales all elements in a matrix by the given scalar factor.
+		/// </summary>
+		/// <param name="value1">The source matrix.</param>
+		/// <param name="value2">The scaling value to use.</param>
+		/// <returns>The resulting matrix.</returns>
+		public static Matrix3x2 operator *(Matrix3x2 value1, Fix64 value2)
+		{
+			Matrix3x2 m;
+
+			m.M11 = value1.M11 * value2;
+			m.M12 = value1.M12 * value2;
+			m.M21 = value1.M21 * value2;
+			m.M22 = value1.M22 * value2;
+			m.M31 = value1.M31 * value2;
+			m.M32 = value1.M32 * value2;
+
+			return m;
+		}
+
+		/// <summary>
+		/// Returns a boolean indicating whether the given matrices are equal.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>True if the matrices are equal; False otherwise.</returns>
+		public static bool operator ==(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			return (value1.M11 == value2.M11 && value1.M22 == value2.M22 && // Check diagonal element first for early out.
+												value1.M12 == value2.M12 &&
+					value1.M21 == value2.M21 &&
+					value1.M31 == value2.M31 && value1.M32 == value2.M32);
+		}
+
+		/// <summary>
+		/// Returns a boolean indicating whether the given matrices are not equal.
+		/// </summary>
+		/// <param name="value1">The first source matrix.</param>
+		/// <param name="value2">The second source matrix.</param>
+		/// <returns>True if the matrices are not equal; False if they are equal.</returns>
+		public static bool operator !=(Matrix3x2 value1, Matrix3x2 value2)
+		{
+			return (value1.M11 != value2.M11 || value1.M12 != value2.M12 ||
+					value1.M21 != value2.M21 || value1.M22 != value2.M22 ||
+					value1.M31 != value2.M31 || value1.M32 != value2.M32);
+		}
+
+		/// <summary>
+		/// Casts to floating point Matrix3x2.
+		/// </summary>
+		public static explicit operator Math.Float.Matrix3x2(Matrix3x2 matrix)
+		{
+			return new Math.Float.Matrix3x2(
+				(float) matrix.M11, (float) matrix.M12,
+				(float) matrix.M21, (float) matrix.M22,
+				(float) matrix.M31, (float) matrix.M32
+			);
+		}
+
+		/// <summary>
+		/// Returns a boolean indicating whether the matrix is equal to the other given matrix.
+		/// </summary>
+		/// <param name="other">The other matrix to test equality against.</param>
+		/// <returns>True if this matrix is equal to other; False otherwise.</returns>
+		public bool Equals(Matrix3x2 other)
+		{
+			return (M11 == other.M11 && M22 == other.M22 && // Check diagonal element first for early out.
+										M12 == other.M12 &&
+					M21 == other.M21 &&
+					M31 == other.M31 && M32 == other.M32);
+		}
+
+		/// <summary>
+		/// Returns a boolean indicating whether the given Object is equal to this matrix instance.
+		/// </summary>
+		/// <param name="obj">The Object to compare against.</param>
+		/// <returns>True if the Object is equal to this matrix; False otherwise.</returns>
+		public override bool Equals(object obj)
+		{
+			if (obj is Matrix3x2)
+			{
+				return Equals((Matrix3x2) obj);
+			}
+
+			return false;
+		}
+
+		/// <summary>
+		/// Returns a String representing this matrix instance.
+		/// </summary>
+		/// <returns>The string representation.</returns>
+		public override string ToString()
+		{
+			CultureInfo ci = CultureInfo.CurrentCulture;
+			return String.Format(ci, "{{ {{M11:{0} M12:{1}}} {{M21:{2} M22:{3}}} {{M31:{4} M32:{5}}} }}",
+								 M11.ToString(ci), M12.ToString(ci),
+								 M21.ToString(ci), M22.ToString(ci),
+								 M31.ToString(ci), M32.ToString(ci));
+		}
+
+		/// <summary>
+		/// Returns the hash code for this instance.
+		/// </summary>
+		/// <returns>The hash code.</returns>
+		public override int GetHashCode()
+		{
+			return M11.GetHashCode() + M12.GetHashCode() +
+				   M21.GetHashCode() + M22.GetHashCode() +
+				   M31.GetHashCode() + M32.GetHashCode();
+		}
+	}
+}

src/Math/Fixed/Quaternion.cs

@@ -0,0 +1,889 @@
+#region License
+
+/* MoonWorks - Game Development Framework
+ * Copyright 2022 Evan Hemsley
+ */
+
+/* Derived from code by Ethan Lee (Copyright 2009-2021).
+ * Released under the Microsoft Public License.
+ * See fna.LICENSE for details.
+
+ * Derived from code by the Mono.Xna Team (Copyright 2006).
+ * Released under the MIT License. See monoxna.LICENSE for details.
+ */
+
+#endregion
+
+#region Using Statements
+using System;
+using System.Diagnostics;
+
+#endregion
+
+namespace MoonWorks.Math.Fixed
+{
+	/// <summary>
+	/// An efficient mathematical representation for three dimensional fixed point rotations.
+	/// </summary>
+	[Serializable]
+	[DebuggerDisplay("{DebugDisplayString,nq}")]
+	public struct Quaternion : IEquatable<Quaternion>
+	{
+		#region Public Static Properties
+
+		/// <summary>
+		/// Returns a quaternion representing no rotation.
+		/// </summary>
+		public static Quaternion Identity
+		{
+			get
+			{
+				return identity;
+			}
+		}
+
+		#endregion
+
+		#region Internal Properties
+
+		internal string DebugDisplayString
+		{
+			get
+			{
+				if (this == Quaternion.Identity)
+				{
+					return "Identity";
+				}
+
+				return string.Concat(
+					X.ToString(), " ",
+					Y.ToString(), " ",
+					Z.ToString(), " ",
+					W.ToString()
+				);
+			}
+		}
+
+		#endregion
+
+		#region Public Fields
+
+		/// <summary>
+		/// The x coordinate of this <see cref="Quaternion"/>.
+		/// </summary>
+		public Fix64 X;
+
+		/// <summary>
+		/// The y coordinate of this <see cref="Quaternion"/>.
+		/// </summary>
+		public Fix64 Y;
+
+		/// <summary>
+		/// The z coordinate of this <see cref="Quaternion"/>.
+		/// </summary>
+		public Fix64 Z;
+
+		/// <summary>
+		/// The rotation component of this <see cref="Quaternion"/>.
+		/// </summary>
+		public Fix64 W;
+
+		#endregion
+
+		#region Private Static Variables
+
+		private static readonly Quaternion identity = new Quaternion(0, 0, 0, 1);
+
+		#endregion
+
+		#region Public Constructors
+
+		/// <summary>
+		/// Constructs a quaternion with X, Y, Z and W from four values.
+		/// </summary>
+		/// <param name="x">The x coordinate in 3d-space.</param>
+		/// <param name="y">The y coordinate in 3d-space.</param>
+		/// <param name="z">The z coordinate in 3d-space.</param>
+		/// <param name="w">The rotation component.</param>
+		public Quaternion(int x, int y, int z, int w)
+		{
+			X = new Fix64(x);
+			Y = new Fix64(y);
+			Z = new Fix64(z);
+			W = new Fix64(w);
+		}
+
+        public Quaternion(Fix64 x, Fix64 y, Fix64 z, Fix64 w)
+        {
+			X = x;
+			Y = y;
+			Z = z;
+			W = w;
+		}
+
+		/// <summary>
+		/// Constructs a quaternion with X, Y, Z from <see cref="Vector3"/> and rotation component from a scalar.
+		/// </summary>
+		/// <param name="value">The x, y, z coordinates in 3d-space.</param>
+		/// <param name="w">The rotation component.</param>
+		public Quaternion(Vector3 vectorPart, Fix64 scalarPart)
+		{
+			X = vectorPart.X;
+			Y = vectorPart.Y;
+			Z = vectorPart.Z;
+			W = scalarPart;
+		}
+
+		#endregion
+
+		#region Public Methods
+
+		/// <summary>
+		/// Transforms this quaternion into its conjugated version.
+		/// </summary>
+		public void Conjugate()
+		{
+			X = -X;
+			Y = -Y;
+			Z = -Z;
+		}
+
+		/// <summary>
+		/// Compares whether current instance is equal to specified <see cref="Object"/>.
+		/// </summary>
+		/// <param name="obj">The <see cref="Object"/> to compare.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public override bool Equals(object obj)
+		{
+			return (obj is Quaternion) && Equals((Quaternion) obj);
+		}
+
+		/// <summary>
+		/// Compares whether current instance is equal to specified <see cref="Quaternion"/>.
+		/// </summary>
+		/// <param name="other">The <see cref="Quaternion"/> to compare.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public bool Equals(Quaternion other)
+		{
+			return (X == other.X &&
+					Y == other.Y &&
+					Z == other.Z &&
+					W == other.W);
+		}
+
+		/// <summary>
+		/// Gets the hash code of this <see cref="Quaternion"/>.
+		/// </summary>
+		/// <returns>Hash code of this <see cref="Quaternion"/>.</returns>
+		public override int GetHashCode()
+		{
+			return (
+				this.X.GetHashCode() +
+				this.Y.GetHashCode() +
+				this.Z.GetHashCode() +
+				this.W.GetHashCode()
+			);
+		}
+
+		/// <summary>
+		/// Returns the magnitude of the quaternion components.
+		/// </summary>
+		/// <returns>The magnitude of the quaternion components.</returns>
+		public Fix64 Length()
+		{
+			Fix64 num = (
+				(this.X * this.X) +
+				(this.Y * this.Y) +
+				(this.Z * this.Z) +
+				(this.W * this.W)
+			);
+			return (Fix64) Fix64.Sqrt(num);
+		}
+
+		/// <summary>
+		/// Returns the squared magnitude of the quaternion components.
+		/// </summary>
+		/// <returns>The squared magnitude of the quaternion components.</returns>
+		public Fix64 LengthSquared()
+		{
+			return (
+				(this.X * this.X) +
+				(this.Y * this.Y) +
+				(this.Z * this.Z) +
+				(this.W * this.W)
+			);
+		}
+
+		/// <summary>
+		/// Scales the quaternion magnitude to unit length.
+		/// </summary>
+		public void Normalize()
+		{
+			Fix64 num = Fix64.One / (Fix64.Sqrt(
+				(X * X) +
+				(Y * Y) +
+				(Z * Z) +
+				(W * W)
+			));
+			this.X *= num;
+			this.Y *= num;
+			this.Z *= num;
+			this.W *= num;
+		}
+
+		/// <summary>
+		/// Returns a <see cref="String"/> representation of this <see cref="Quaternion"/> in the format:
+		/// {X:[<see cref="X"/>] Y:[<see cref="Y"/>] Z:[<see cref="Z"/>] W:[<see cref="W"/>]}
+		/// </summary>
+		/// <returns>A <see cref="String"/> representation of this <see cref="Quaternion"/>.</returns>
+		public override string ToString()
+		{
+			return (
+				"{X:" + X.ToString() +
+				" Y:" + Y.ToString() +
+				" Z:" + Z.ToString() +
+				" W:" + W.ToString() +
+				"}"
+			);
+		}
+
+		#endregion
+
+		#region Public Static Methods
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains the sum of two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/>.</param>
+		/// <returns>The result of the quaternion addition.</returns>
+		public static Quaternion Add(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Add(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains the sum of two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/>.</param>
+		/// <param name="result">The result of the quaternion addition as an output parameter.</param>
+		public static void Add(
+			ref Quaternion quaternion1,
+			ref Quaternion quaternion2,
+			out Quaternion result
+		)
+		{
+			result.X = quaternion1.X + quaternion2.X;
+			result.Y = quaternion1.Y + quaternion2.Y;
+			result.Z = quaternion1.Z + quaternion2.Z;
+			result.W = quaternion1.W + quaternion2.W;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains concatenation between two quaternion.
+		/// </summary>
+		/// <param name="value1">The first <see cref="Quaternion"/> to concatenate.</param>
+		/// <param name="value2">The second <see cref="Quaternion"/> to concatenate.</param>
+		/// <returns>The result of rotation of <paramref name="value1"/> followed by <paramref name="value2"/> rotation.</returns>
+		public static Quaternion Concatenate(Quaternion value1, Quaternion value2)
+		{
+			Quaternion quaternion;
+			Concatenate(ref value1, ref value2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains concatenation between two quaternion.
+		/// </summary>
+		/// <param name="value1">The first <see cref="Quaternion"/> to concatenate.</param>
+		/// <param name="value2">The second <see cref="Quaternion"/> to concatenate.</param>
+		/// <param name="result">The result of rotation of <paramref name="value1"/> followed by <paramref name="value2"/> rotation as an output parameter.</param>
+		public static void Concatenate(
+			ref Quaternion value1,
+			ref Quaternion value2,
+			out Quaternion result
+		)
+		{
+			Fix64 x1 = value1.X;
+			Fix64 y1 = value1.Y;
+			Fix64 z1 = value1.Z;
+			Fix64 w1 = value1.W;
+
+			Fix64 x2 = value2.X;
+			Fix64 y2 = value2.Y;
+			Fix64 z2 = value2.Z;
+			Fix64 w2 = value2.W;
+
+			result.X = ((x2 * w1) + (x1 * w2)) + ((y2 * z1) - (z2 * y1));
+			result.Y = ((y2 * w1) + (y1 * w2)) + ((z2 * x1) - (x2 * z1));
+			result.Z = ((z2 * w1) + (z1 * w2)) + ((x2 * y1) - (y2 * x1));
+			result.W = (w2 * w1) - (((x2 * x1) + (y2 * y1)) + (z2 * z1));
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains conjugated version of the specified quaternion.
+		/// </summary>
+		/// <param name="value">The quaternion which values will be used to create the conjugated version.</param>
+		/// <returns>The conjugate version of the specified quaternion.</returns>
+		public static Quaternion Conjugate(Quaternion value)
+		{
+			return new Quaternion(-value.X, -value.Y, -value.Z, value.W);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains conjugated version of the specified quaternion.
+		/// </summary>
+		/// <param name="value">The quaternion which values will be used to create the conjugated version.</param>
+		/// <param name="result">The conjugated version of the specified quaternion as an output parameter.</param>
+		public static void Conjugate(ref Quaternion value, out Quaternion result)
+		{
+			result.X = -value.X;
+			result.Y = -value.Y;
+			result.Z = -value.Z;
+			result.W = value.W;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> from the specified axis and angle.
+		/// </summary>
+		/// <param name="axis">The axis of rotation.</param>
+		/// <param name="angle">The angle in radians.</param>
+		/// <returns>The new quaternion builded from axis and angle.</returns>
+		public static Quaternion CreateFromAxisAngle(Vector3 axis, Fix64 angle)
+		{
+			Quaternion quaternion;
+			CreateFromAxisAngle(ref axis, angle, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> from the specified axis and angle.
+		/// </summary>
+		/// <param name="axis">The axis of rotation.</param>
+		/// <param name="angle">The angle in radians.</param>
+		/// <param name="result">The new quaternion builded from axis and angle as an output parameter.</param>
+		public static void CreateFromAxisAngle(
+			ref Vector3 axis,
+			Fix64 angle,
+			out Quaternion result
+		)
+		{
+			Fix64 half = angle / new Fix64(2);
+			Fix64 sin = Fix64.Sin(half);
+			Fix64 cos = Fix64.Cos(half);
+			result.X = axis.X * sin;
+			result.Y = axis.Y * sin;
+			result.Z = axis.Z * sin;
+			result.W = cos;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> from the specified <see cref="Matrix4x4"/>.
+		/// </summary>
+		/// <param name="matrix">The rotation matrix.</param>
+		/// <returns>A quaternion composed from the rotation part of the matrix.</returns>
+		public static Quaternion CreateFromRotationMatrix(Matrix4x4 matrix)
+		{
+			Quaternion quaternion;
+			CreateFromRotationMatrix(ref matrix, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> from the specified <see cref="Matrix4x4"/>.
+		/// </summary>
+		/// <param name="matrix">The rotation matrix.</param>
+		/// <param name="result">A quaternion composed from the rotation part of the matrix as an output parameter.</param>
+		public static void CreateFromRotationMatrix(ref Matrix4x4 matrix, out Quaternion result)
+		{
+			Fix64 sqrt;
+			Fix64 half;
+			Fix64 scale = matrix.M11 + matrix.M22 + matrix.M33;
+			Fix64 two = new Fix64(2);
+
+			if (scale > Fix64.Zero)
+			{
+				sqrt = Fix64.Sqrt(scale + Fix64.One);
+				result.W = sqrt / two;
+				sqrt = Fix64.One / (sqrt * two);
+
+				result.X = (matrix.M23 - matrix.M32) * sqrt;
+				result.Y = (matrix.M31 - matrix.M13) * sqrt;
+				result.Z = (matrix.M12 - matrix.M21) * sqrt;
+			}
+			else if ((matrix.M11 >= matrix.M22) && (matrix.M11 >= matrix.M33))
+			{
+				sqrt = Fix64.Sqrt(Fix64.One + matrix.M11 - matrix.M22 - matrix.M33);
+				half = Fix64.One / (sqrt * two);
+
+				result.X = sqrt / two;
+				result.Y = (matrix.M12 + matrix.M21) * half;
+				result.Z = (matrix.M13 + matrix.M31) * half;
+				result.W = (matrix.M23 - matrix.M32) * half;
+			}
+			else if (matrix.M22 > matrix.M33)
+			{
+				sqrt = Fix64.Sqrt(Fix64.One + matrix.M22 - matrix.M11 - matrix.M33);
+				half = Fix64.One / (sqrt * two);
+
+				result.X = (matrix.M21 + matrix.M12) * half;
+				result.Y = sqrt / two;
+				result.Z = (matrix.M32 + matrix.M23) * half;
+				result.W = (matrix.M31 - matrix.M13) * half;
+			}
+			else
+			{
+				sqrt = Fix64.Sqrt(Fix64.One + matrix.M33 - matrix.M11 - matrix.M22);
+				half = Fix64.One / (sqrt * two);
+
+				result.X = (matrix.M31 + matrix.M13) * half;
+				result.Y = (matrix.M32 + matrix.M23) * half;
+				result.Z = sqrt / two;
+				result.W = (matrix.M12 - matrix.M21) * half;
+			}
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> from the specified yaw, pitch and roll angles.
+		/// </summary>
+		/// <param name="yaw">Yaw around the y axis in radians.</param>
+		/// <param name="pitch">Pitch around the x axis in radians.</param>
+		/// <param name="roll">Roll around the z axis in radians.</param>
+		/// <returns>A new quaternion from the concatenated yaw, pitch, and roll angles.</returns>
+		public static Quaternion CreateFromYawPitchRoll(Fix64 yaw, Fix64 pitch, Fix64 roll)
+		{
+			Quaternion quaternion;
+			CreateFromYawPitchRoll(yaw, pitch, roll, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> from the specified yaw, pitch and roll angles.
+		/// </summary>
+		/// <param name="yaw">Yaw around the y axis in radians.</param>
+		/// <param name="pitch">Pitch around the x axis in radians.</param>
+		/// <param name="roll">Roll around the z axis in radians.</param>
+		/// <param name="result">A new quaternion from the concatenated yaw, pitch, and roll angles as an output parameter.</param>
+		public static void CreateFromYawPitchRoll(
+			Fix64 yaw,
+			Fix64 pitch,
+			Fix64 roll,
+			out Quaternion result)
+		{
+			Fix64 two = new Fix64(2);
+			Fix64 halfRoll = roll / two;;
+			Fix64 sinRoll = Fix64.Sin(halfRoll);
+			Fix64 cosRoll = Fix64.Cos(halfRoll);
+			Fix64 halfPitch = pitch / two;
+			Fix64 sinPitch = Fix64.Sin(halfPitch);
+			Fix64 cosPitch = Fix64.Cos(halfPitch);
+			Fix64 halfYaw = yaw / two;
+			Fix64 sinYaw = Fix64.Sin(halfYaw);
+			Fix64 cosYaw = Fix64.Cos(halfYaw);
+			result.X = ((cosYaw * sinPitch) * cosRoll) + ((sinYaw * cosPitch) * sinRoll);
+			result.Y = ((sinYaw * cosPitch) * cosRoll) - ((cosYaw * sinPitch) * sinRoll);
+			result.Z = ((cosYaw * cosPitch) * sinRoll) - ((sinYaw * sinPitch) * cosRoll);
+			result.W = ((cosYaw * cosPitch) * cosRoll) + ((sinYaw * sinPitch) * sinRoll);
+		}
+
+		/// <summary>
+		/// Divides a <see cref="Quaternion"/> by the other <see cref="Quaternion"/>.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Divisor <see cref="Quaternion"/>.</param>
+		/// <returns>The result of dividing the quaternions.</returns>
+		public static Quaternion Divide(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Divide(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Divides a <see cref="Quaternion"/> by the other <see cref="Quaternion"/>.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Divisor <see cref="Quaternion"/>.</param>
+		/// <param name="result">The result of dividing the quaternions as an output parameter.</param>
+		public static void Divide(
+			ref Quaternion quaternion1,
+			ref Quaternion quaternion2,
+			out Quaternion result
+		)
+		{
+			Fix64 x = quaternion1.X;
+			Fix64 y = quaternion1.Y;
+			Fix64 z = quaternion1.Z;
+			Fix64 w = quaternion1.W;
+			Fix64 num14 = (
+				(quaternion2.X * quaternion2.X) +
+				(quaternion2.Y * quaternion2.Y) +
+				(quaternion2.Z * quaternion2.Z) +
+				(quaternion2.W * quaternion2.W)
+			);
+			Fix64 num5 = Fix64.One / num14;
+			Fix64 num4 = -quaternion2.X * num5;
+			Fix64 num3 = -quaternion2.Y * num5;
+			Fix64 num2 = -quaternion2.Z * num5;
+			Fix64 num = quaternion2.W * num5;
+			Fix64 num13 = (y * num2) - (z * num3);
+			Fix64 num12 = (z * num4) - (x * num2);
+			Fix64 num11 = (x * num3) - (y * num4);
+			Fix64 num10 = ((x * num4) + (y * num3)) + (z * num2);
+			result.X = ((x * num) + (num4 * w)) + num13;
+			result.Y = ((y * num) + (num3 * w)) + num12;
+			result.Z = ((z * num) + (num2 * w)) + num11;
+			result.W = (w * num) - num10;
+		}
+
+		/// <summary>
+		/// Returns a dot product of two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">The first quaternion.</param>
+		/// <param name="quaternion2">The second quaternion.</param>
+		/// <returns>The dot product of two quaternions.</returns>
+		public static Fix64 Dot(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			return (
+				(quaternion1.X * quaternion2.X) +
+				(quaternion1.Y * quaternion2.Y) +
+				(quaternion1.Z * quaternion2.Z) +
+				(quaternion1.W * quaternion2.W)
+			);
+		}
+
+		/// <summary>
+		/// Returns a dot product of two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">The first quaternion.</param>
+		/// <param name="quaternion2">The second quaternion.</param>
+		/// <param name="result">The dot product of two quaternions as an output parameter.</param>
+		public static void Dot(
+			ref Quaternion quaternion1,
+			ref Quaternion quaternion2,
+			out Fix64 result
+		)
+		{
+			result = (
+				(quaternion1.X * quaternion2.X) +
+				(quaternion1.Y * quaternion2.Y) +
+				(quaternion1.Z * quaternion2.Z) +
+				(quaternion1.W * quaternion2.W)
+			);
+		}
+
+		/// <summary>
+		/// Returns the inverse quaternion which represents the opposite rotation.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/>.</param>
+		/// <returns>The inverse quaternion.</returns>
+		public static Quaternion Inverse(Quaternion quaternion)
+		{
+			Quaternion inverse;
+			Inverse(ref quaternion, out inverse);
+			return inverse;
+		}
+
+		/// <summary>
+		/// Returns the inverse quaternion which represents the opposite rotation.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/>.</param>
+		/// <param name="result">The inverse quaternion as an output parameter.</param>
+		public static void Inverse(ref Quaternion quaternion, out Quaternion result)
+		{
+			Fix64 num2 = (
+				(quaternion.X * quaternion.X) +
+				(quaternion.Y * quaternion.Y) +
+				(quaternion.Z * quaternion.Z) +
+				(quaternion.W * quaternion.W)
+			);
+			Fix64 num = Fix64.One / num2;
+			result.X = -quaternion.X * num;
+			result.Y = -quaternion.Y * num;
+			result.Z = -quaternion.Z * num;
+			result.W = quaternion.W * num;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains subtraction of one <see cref="Quaternion"/> from another.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/>.</param>
+		/// <returns>The result of the quaternion subtraction.</returns>
+		public static Quaternion Subtract(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Subtract(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains subtraction of one <see cref="Quaternion"/> from another.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/>.</param>
+		/// <param name="result">The result of the quaternion subtraction as an output parameter.</param>
+		public static void Subtract(
+			ref Quaternion quaternion1,
+			ref Quaternion quaternion2,
+			out Quaternion result
+		)
+		{
+			result.X = quaternion1.X - quaternion2.X;
+			result.Y = quaternion1.Y - quaternion2.Y;
+			result.Z = quaternion1.Z - quaternion2.Z;
+			result.W = quaternion1.W - quaternion2.W;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains a multiplication of two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/>.</param>
+		/// <returns>The result of the quaternion multiplication.</returns>
+		public static Quaternion Multiply(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Multiply(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains a multiplication of <see cref="Quaternion"/> and a scalar.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="scaleFactor">Scalar value.</param>
+		/// <returns>The result of the quaternion multiplication with a scalar.</returns>
+		public static Quaternion Multiply(Quaternion quaternion1, Fix64 scaleFactor)
+		{
+			Quaternion quaternion;
+			Multiply(ref quaternion1, scaleFactor, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains a multiplication of two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/>.</param>
+		/// <param name="result">The result of the quaternion multiplication as an output parameter.</param>
+		public static void Multiply(
+			ref Quaternion quaternion1,
+			ref Quaternion quaternion2,
+			out Quaternion result
+		)
+		{
+			Fix64 x = quaternion1.X;
+			Fix64 y = quaternion1.Y;
+			Fix64 z = quaternion1.Z;
+			Fix64 w = quaternion1.W;
+			Fix64 num4 = quaternion2.X;
+			Fix64 num3 = quaternion2.Y;
+			Fix64 num2 = quaternion2.Z;
+			Fix64 num = quaternion2.W;
+			Fix64 num12 = (y * num2) - (z * num3);
+			Fix64 num11 = (z * num4) - (x * num2);
+			Fix64 num10 = (x * num3) - (y * num4);
+			Fix64 num9 = ((x * num4) + (y * num3)) + (z * num2);
+			result.X = ((x * num) + (num4 * w)) + num12;
+			result.Y = ((y * num) + (num3 * w)) + num11;
+			result.Z = ((z * num) + (num2 * w)) + num10;
+			result.W = (w * num) - num9;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Quaternion"/> that contains a multiplication of <see cref="Quaternion"/> and a scalar.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/>.</param>
+		/// <param name="scaleFactor">Scalar value.</param>
+		/// <param name="result">The result of the quaternion multiplication with a scalar as an output parameter.</param>
+		public static void Multiply(
+			ref Quaternion quaternion1,
+			Fix64 scaleFactor,
+			out Quaternion result
+		)
+		{
+			result.X = quaternion1.X * scaleFactor;
+			result.Y = quaternion1.Y * scaleFactor;
+			result.Z = quaternion1.Z * scaleFactor;
+			result.W = quaternion1.W * scaleFactor;
+		}
+
+		/// <summary>
+		/// Flips the sign of the all the quaternion components.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/>.</param>
+		/// <returns>The result of the quaternion negation.</returns>
+		public static Quaternion Negate(Quaternion quaternion)
+		{
+			return new Quaternion(
+				-quaternion.X,
+				-quaternion.Y,
+				-quaternion.Z,
+				-quaternion.W
+			);
+		}
+
+		/// <summary>
+		/// Flips the sign of the all the quaternion components.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/>.</param>
+		/// <param name="result">The result of the quaternion negation as an output parameter.</param>
+		public static void Negate(ref Quaternion quaternion, out Quaternion result)
+		{
+			result.X = -quaternion.X;
+			result.Y = -quaternion.Y;
+			result.Z = -quaternion.Z;
+			result.W = -quaternion.W;
+		}
+
+		/// <summary>
+		/// Scales the quaternion magnitude to unit length.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/>.</param>
+		/// <returns>The unit length quaternion.</returns>
+		public static Quaternion Normalize(Quaternion quaternion)
+		{
+			Quaternion quaternion2;
+			Normalize(ref quaternion, out quaternion2);
+			return quaternion2;
+		}
+
+		/// <summary>
+		/// Scales the quaternion magnitude to unit length.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/>.</param>
+		/// <param name="result">The unit length quaternion an output parameter.</param>
+		public static void Normalize(ref Quaternion quaternion, out Quaternion result)
+		{
+			Fix64 num = Fix64.One / (Fix64.Sqrt(
+				(quaternion.X * quaternion.X) +
+				(quaternion.Y * quaternion.Y) +
+				(quaternion.Z * quaternion.Z) +
+				(quaternion.W * quaternion.W)
+			));
+			result.X = quaternion.X * num;
+			result.Y = quaternion.Y * num;
+			result.Z = quaternion.Z * num;
+			result.W = quaternion.W * num;
+		}
+
+		public static Quaternion LookAt(in Vector3 forward, in Vector3 up)
+		{
+			Matrix4x4 orientation = Matrix4x4.Identity;
+			orientation.Forward = forward;
+			orientation.Right = Vector3.Normalize(Vector3.Cross(forward, up));
+			orientation.Up = Vector3.Cross(orientation.Right, forward);
+
+			return Quaternion.CreateFromRotationMatrix(orientation);
+		}
+
+		#endregion
+
+		#region Public Static Operator Overloads
+
+		/// <summary>
+		/// Adds two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/> on the left of the add sign.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/> on the right of the add sign.</param>
+		/// <returns>Sum of the vectors.</returns>
+		public static Quaternion operator +(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Add(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Divides a <see cref="Quaternion"/> by the other <see cref="Quaternion"/>.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/> on the left of the div sign.</param>
+		/// <param name="quaternion2">Divisor <see cref="Quaternion"/> on the right of the div sign.</param>
+		/// <returns>The result of dividing the quaternions.</returns>
+		public static Quaternion operator /(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Divide(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Compares whether two <see cref="Quaternion"/> instances are equal.
+		/// </summary>
+		/// <param name="quaternion1"><see cref="Quaternion"/> instance on the left of the equal sign.</param>
+		/// <param name="quaternion2"><see cref="Quaternion"/> instance on the right of the equal sign.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public static bool operator ==(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			return quaternion1.Equals(quaternion2);
+		}
+
+		/// <summary>
+		/// Compares whether two <see cref="Quaternion"/> instances are not equal.
+		/// </summary>
+		/// <param name="quaternion1"><see cref="Quaternion"/> instance on the left of the not equal sign.</param>
+		/// <param name="quaternion2"><see cref="Quaternion"/> instance on the right of the not equal sign.</param>
+		/// <returns><c>true</c> if the instances are not equal; <c>false</c> otherwise.</returns>
+		public static bool operator !=(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			return !quaternion1.Equals(quaternion2);
+		}
+
+		/// <summary>
+		/// Multiplies two quaternions.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Quaternion"/> on the left of the mul sign.</param>
+		/// <param name="quaternion2">Source <see cref="Quaternion"/> on the right of the mul sign.</param>
+		/// <returns>Result of the quaternions multiplication.</returns>
+		public static Quaternion operator *(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Multiply(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Multiplies the components of quaternion by a scalar.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Vector3"/> on the left of the mul sign.</param>
+		/// <param name="scaleFactor">Scalar value on the right of the mul sign.</param>
+		/// <returns>Result of the quaternion multiplication with a scalar.</returns>
+		public static Quaternion operator *(Quaternion quaternion1, Fix64 scaleFactor)
+		{
+			Quaternion quaternion;
+			Multiply(ref quaternion1, scaleFactor, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Subtracts a <see cref="Quaternion"/> from a <see cref="Quaternion"/>.
+		/// </summary>
+		/// <param name="quaternion1">Source <see cref="Vector3"/> on the left of the sub sign.</param>
+		/// <param name="quaternion2">Source <see cref="Vector3"/> on the right of the sub sign.</param>
+		/// <returns>Result of the quaternion subtraction.</returns>
+		public static Quaternion operator -(Quaternion quaternion1, Quaternion quaternion2)
+		{
+			Quaternion quaternion;
+			Subtract(ref quaternion1, ref quaternion2, out quaternion);
+			return quaternion;
+		}
+
+		/// <summary>
+		/// Flips the sign of the all the quaternion components.
+		/// </summary>
+		/// <param name="quaternion">Source <see cref="Quaternion"/> on the right of the sub sign.</param>
+		/// <returns>The result of the quaternion negation.</returns>
+		public static Quaternion operator -(Quaternion quaternion)
+		{
+			Quaternion quaternion2;
+			Negate(ref quaternion, out quaternion2);
+			return quaternion2;
+		}
+
+		#endregion
+	}
+}

src/Math/Fixed/Transform2D.cs

@@ -0,0 +1,105 @@
+namespace MoonWorks.Math.Fixed
+{
+	public struct Transform2D : System.IEquatable<Transform2D>
+	{
+		public Vector2 Position { get; }
+		public Fix64 Rotation { get; }
+		public Vector2 Scale { get; }
+
+		private bool transformMatrixCalculated;
+		private Matrix3x2 transformMatrix;
+
+		public Matrix3x2 TransformMatrix
+		{
+			get
+			{
+				if (!transformMatrixCalculated)
+				{
+					transformMatrix = CreateTransformMatrix(Position, Rotation, Scale);
+					transformMatrixCalculated = true;
+				}
+
+				return transformMatrix;
+			}
+		}
+
+		public bool IsAxisAligned => Rotation % Fix64.PiOver2 == Fix64.Zero;
+		public bool IsUniformScale => Scale.X == Scale.Y;
+
+		public static readonly Transform2D Identity = new Transform2D(Vector2.Zero, Fix64.Zero, Vector2.One);
+
+		public Transform2D(Vector2 position)
+		{
+			Position = position;
+			Rotation = Fix64.Zero;
+			Scale = Vector2.One;
+			transformMatrixCalculated = false;
+			transformMatrix = Matrix3x2.Identity;
+		}
+
+		public Transform2D(Vector2 position, Fix64 rotation)
+		{
+			Position = position;
+			Rotation = rotation;
+			Scale = Vector2.One;
+			transformMatrixCalculated = false;
+			transformMatrix = Matrix3x2.Identity;
+		}
+
+		public Transform2D(Vector2 position, Fix64 rotation, Vector2 scale)
+		{
+			Position = position;
+			Rotation = rotation;
+			Scale = scale;
+			transformMatrixCalculated = false;
+			transformMatrix = Matrix3x2.Identity;
+		}
+
+		public Transform2D Compose(Transform2D other)
+		{
+			return new Transform2D(Position + other.Position, Rotation + other.Rotation, Scale * other.Scale);
+		}
+
+		private static Matrix3x2 CreateTransformMatrix(Vector2 position, Fix64 rotation, Vector2 scale)
+		{
+			return
+				Matrix3x2.CreateScale(scale) *
+				Matrix3x2.CreateRotation(rotation) *
+				Matrix3x2.CreateTranslation(position);
+		}
+
+		public bool Equals(Transform2D other)
+		{
+			return
+				Position == other.Position &&
+				Rotation == other.Rotation &&
+				Scale == other.Scale;
+		}
+
+
+        public override bool Equals(System.Object other)
+        {
+            if (other is Transform2D otherTransform)
+            {
+                return Equals(otherTransform);
+            }
+
+            return false;
+        }
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Position, Rotation, Scale);
+		}
+
+		public static bool operator ==(Transform2D a, Transform2D b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Transform2D a, Transform2D b)
+		{
+			return !a.Equals(b);
+		}
+	}
+}

src/Math/Fixed/Vector2.cs

@@ -0,0 +1,838 @@
+#region License
+
+/* MoonWorks - Game Development Framework
+ * Copyright 2022 Evan Hemsley
+ */
+
+/* Derived from code by Ethan Lee (Copyright 2009-2021).
+ * Released under the Microsoft Public License.
+ * See fna.LICENSE for details.
+
+ * Derived from code by the Mono.Xna Team (Copyright 2006).
+ * Released under the MIT License. See monoxna.LICENSE for details.
+ */
+
+#endregion
+
+#region Using Statements
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+#endregion
+
+namespace MoonWorks.Math.Fixed
+{
+	/// <summary>
+	/// Describes a fixed point 2D-vector.
+	/// </summary>
+	[Serializable]
+	[DebuggerDisplay("{DebugDisplayString,nq}")]
+	[StructLayout(LayoutKind.Explicit)]
+	public struct Vector2 : IEquatable<Vector2>
+	{
+		#region Public Static Properties
+
+		/// <summary>
+		/// Returns a <see cref="Vector2"/> with components 0, 0.
+		/// </summary>
+		public static Vector2 Zero
+		{
+			get
+			{
+				return zeroVector;
+			}
+		}
+
+		/// <summary>
+		/// Returns a <see cref="Vector2"/> with components 1, 1.
+		/// </summary>
+		public static Vector2 One
+		{
+			get
+			{
+				return unitVector;
+			}
+		}
+
+		/// <summary>
+		/// Returns a <see cref="Vector2"/> with components 1, 0.
+		/// </summary>
+		public static Vector2 UnitX
+		{
+			get
+			{
+				return unitXVector;
+			}
+		}
+
+		/// <summary>
+		/// Returns a <see cref="Vector2"/> with components 0, 1.
+		/// </summary>
+		public static Vector2 UnitY
+		{
+			get
+			{
+				return unitYVector;
+			}
+		}
+
+		#endregion
+
+		#region Internal Properties
+
+		internal string DebugDisplayString
+		{
+			get
+			{
+				return string.Concat(
+					X.ToString(), " ",
+					Y.ToString()
+				);
+			}
+		}
+
+		#endregion
+
+		#region Public Fields
+
+		/// <summary>
+		/// The x coordinate of this <see cref="Vector2"/>.
+		/// </summary>
+		[FieldOffset(0)]
+		public Fix64 X;
+
+		/// <summary>
+		/// The y coordinate of this <see cref="Vector2"/>.
+		/// </summary>
+		[FieldOffset(8)]
+		public Fix64 Y;
+
+		#endregion
+
+		#region Private Static Fields
+
+		private static readonly Vector2 zeroVector = new Vector2(0, 0);
+		private static readonly Vector2 unitVector = new Vector2(1, 1);
+		private static readonly Vector2 unitXVector = new Vector2(1, 0);
+		private static readonly Vector2 unitYVector = new Vector2(0, 1);
+
+		#endregion
+
+		#region Public Constructors
+
+		/// <summary>
+		/// Constructs a 2d vector with X and Y from two values.
+		/// </summary>
+		/// <param name="x">The x coordinate in 2d-space.</param>
+		/// <param name="y">The y coordinate in 2d-space.</param>
+		public Vector2(Fix64 x, Fix64 y)
+		{
+			this.X = x;
+			this.Y = y;
+		}
+
+		/// <summary>
+		/// Constructs a 2d vector with X and Y set to the same value.
+		/// </summary>
+		/// <param name="value">The x and y coordinates in 2d-space.</param>
+		public Vector2(Fix64 value)
+		{
+			this.X = value;
+			this.Y = value;
+		}
+
+		public Vector2(int x, int y)
+		{
+			this.X = new Fix64(x);
+			this.Y = new Fix64(y);
+		}
+
+		#endregion
+
+		#region Public Methods
+
+		/// <summary>
+		/// Compares whether current instance is equal to specified <see cref="Object"/>.
+		/// </summary>
+		/// <param name="obj">The <see cref="Object"/> to compare.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public override bool Equals(object obj)
+		{
+			return obj is Vector2 fixVector && Equals(fixVector);
+		}
+
+		/// <summary>
+		/// Compares whether current instance is equal to specified <see cref="Vector2"/>.
+		/// </summary>
+		/// <param name="other">The <see cref="Vector2"/> to compare.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public bool Equals(Vector2 other)
+		{
+			return (X == other.X &&
+					Y == other.Y);
+		}
+
+		/// <summary>
+		/// Gets the hash code of this <see cref="Vector2"/>.
+		/// </summary>
+		/// <returns>Hash code of this <see cref="Vector2"/>.</returns>
+		public override int GetHashCode()
+		{
+			return X.GetHashCode() + Y.GetHashCode();
+		}
+
+		/// <summary>
+		/// Returns the length of this <see cref="Vector2"/>.
+		/// </summary>
+		/// <returns>The length of this <see cref="Vector2"/>.</returns>
+		public Fix64 Length()
+		{
+			return Fix64.Sqrt((X * X) + (Y * Y));
+		}
+
+		/// <summary>
+		/// Returns the squared length of this <see cref="Vector2"/>.
+		/// </summary>
+		/// <returns>The squared length of this <see cref="Vector2"/>.</returns>
+		public Fix64 LengthSquared()
+		{
+			return (X * X) + (Y * Y);
+		}
+
+		/// <summary>
+		/// Turns this <see cref="Vector2"/> to a unit vector with the same direction.
+		/// </summary>
+		public void Normalize()
+		{
+			Fix64 val = Fix64.One / Fix64.Sqrt((X * X) + (Y * Y));
+			X *= val;
+			Y *= val;
+		}
+
+		/// <summary>
+		/// Turns this <see cref="Vector2"/> to an angle in radians.
+		/// </summary>
+		public Fix64 Angle()
+		{
+			return Fix64.Atan2(Y, X);
+		}
+
+		/// <summary>
+		/// Returns this Vector2 with the fractional components cut off.
+		/// </summary>
+		public Vector2 Truncated()
+		{
+			return new Vector2((int) X, (int) Y);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains linear interpolation of the specified vectors.
+		/// </summary>
+		/// <param name="value1">The first vector.</param>
+		/// <param name="value2">The second vector.</param>
+		/// <param name="amount">Weighting value(between 0.0 and 1.0).</param>
+		/// <returns>The result of linear interpolation of the specified vectors.</returns>
+		public static Vector2 Lerp(Vector2 value1, Vector2 value2, Fix64 amount)
+		{
+			return new Vector2(
+				Fix64.Lerp(value1.X, value2.X, amount),
+				Fix64.Lerp(value1.Y, value2.Y, amount)
+			);
+		}
+
+		/// <summary>
+		/// Returns a <see cref="String"/> representation of this <see cref="Vector2"/> in the format:
+		/// {X:[<see cref="X"/>] Y:[<see cref="Y"/>]}
+		/// </summary>
+		/// <returns>A <see cref="String"/> representation of this <see cref="Vector2"/>.</returns>
+		public override string ToString()
+		{
+			return (
+				"{X:" + X.ToString() +
+				" Y:" + Y.ToString() +
+				"}"
+			);
+		}
+
+		#endregion
+
+		#region Public Static Methods
+
+		/// <summary>
+		/// Performs vector addition on <paramref name="value1"/> and <paramref name="value2"/>.
+		/// </summary>
+		/// <param name="value1">The first vector to add.</param>
+		/// <param name="value2">The second vector to add.</param>
+		/// <returns>The result of the vector addition.</returns>
+		public static Vector2 Add(Vector2 value1, Vector2 value2)
+		{
+			value1.X += value2.X;
+			value1.Y += value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Clamps the specified value within a range.
+		/// </summary>
+		/// <param name="value1">The value to clamp.</param>
+		/// <param name="min">The min value.</param>
+		/// <param name="max">The max value.</param>
+		/// <returns>The clamped value.</returns>
+		public static Vector2 Clamp(Vector2 value1, Vector2 min, Vector2 max)
+		{
+			return new Vector2(
+				Fix64.Clamp(value1.X, min.X, max.X),
+				Fix64.Clamp(value1.Y, min.Y, max.Y)
+			);
+		}
+
+		/// <summary>
+		/// Returns the distance between two vectors.
+		/// </summary>
+		/// <param name="value1">The first vector.</param>
+		/// <param name="value2">The second vector.</param>
+		/// <returns>The distance between two vectors.</returns>
+		public static Fix64 Distance(Vector2 value1, Vector2 value2)
+		{
+			Fix64 v1 = value1.X - value2.X, v2 = value1.Y - value2.Y;
+			return Fix64.Sqrt((v1 * v1) + (v2 * v2));
+		}
+
+		/// <summary>
+		/// Returns the squared distance between two vectors.
+		/// </summary>
+		/// <param name="value1">The first vector.</param>
+		/// <param name="value2">The second vector.</param>
+		/// <returns>The squared distance between two vectors.</returns>
+		public static Fix64 DistanceSquared(Vector2 value1, Vector2 value2)
+		{
+			Fix64 v1 = value1.X - value2.X, v2 = value1.Y - value2.Y;
+			return (v1 * v1) + (v2 * v2);
+		}
+
+		/// <summary>
+		/// Divides the components of a <see cref="Vector2"/> by the components of another <see cref="Vector2"/>.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/>.</param>
+		/// <param name="value2">Divisor <see cref="Vector2"/>.</param>
+		/// <returns>The result of dividing the vectors.</returns>
+		public static Vector2 Divide(Vector2 value1, Vector2 value2)
+		{
+			value1.X /= value2.X;
+			value1.Y /= value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Divides the components of a <see cref="Vector2"/> by a scalar.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/>.</param>
+		/// <param name="divider">Divisor scalar.</param>
+		/// <returns>The result of dividing a vector by a scalar.</returns>
+		public static Vector2 Divide(Vector2 value1, Fix64 divider)
+		{
+			Fix64 factor = Fix64.One / divider;
+			value1.X *= factor;
+			value1.Y *= factor;
+			return value1;
+		}
+
+		/// <summary>
+		/// Returns a dot product of two vectors.
+		/// </summary>
+		/// <param name="value1">The first vector.</param>
+		/// <param name="value2">The second vector.</param>
+		/// <returns>The dot product of two vectors.</returns>
+		public static Fix64 Dot(Vector2 value1, Vector2 value2)
+		{
+			return (value1.X * value2.X) + (value1.Y * value2.Y);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a maximal values from the two vectors.
+		/// </summary>
+		/// <param name="value1">The first vector.</param>
+		/// <param name="value2">The second vector.</param>
+		/// <returns>The <see cref="Vector2"/> with maximal values from the two vectors.</returns>
+		public static Vector2 Max(Vector2 value1, Vector2 value2)
+		{
+			return new Vector2(
+				value1.X > value2.X ? value1.X : value2.X,
+				value1.Y > value2.Y ? value1.Y : value2.Y
+			);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a minimal values from the two vectors.
+		/// </summary>
+		/// <param name="value1">The first vector.</param>
+		/// <param name="value2">The second vector.</param>
+		/// <returns>The <see cref="Vector2"/> with minimal values from the two vectors.</returns>
+		public static Vector2 Min(Vector2 value1, Vector2 value2)
+		{
+			return new Vector2(
+				value1.X < value2.X ? value1.X : value2.X,
+				value1.Y < value2.Y ? value1.Y : value2.Y
+			);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a multiplication of two vectors.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/>.</param>
+		/// <param name="value2">Source <see cref="Vector2"/>.</param>
+		/// <returns>The result of the vector multiplication.</returns>
+		public static Vector2 Multiply(Vector2 value1, Vector2 value2)
+		{
+			value1.X *= value2.X;
+			value1.Y *= value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a multiplication of <see cref="Vector2"/> and a scalar.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/>.</param>
+		/// <param name="scaleFactor">Scalar value.</param>
+		/// <returns>The result of the vector multiplication with a scalar.</returns>
+		public static Vector2 Multiply(Vector2 value1, Fix64 scaleFactor)
+		{
+			value1.X *= scaleFactor;
+			value1.Y *= scaleFactor;
+			return value1;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains the specified vector inversion.
+		/// direction of <paramref name="value"/>.
+		/// </summary>
+		/// <param name="value">Source <see cref="Vector2"/>.</param>
+		/// <returns>The result of the vector inversion.</returns>
+		public static Vector2 Negate(Vector2 value)
+		{
+			value.X = -value.X;
+			value.Y = -value.Y;
+			return value;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a normalized values from another vector.
+		/// </summary>
+		/// <param name="value">Source <see cref="Vector2"/>.</param>
+		/// <returns>Unit vector.</returns>
+		public static Vector2 Normalize(Vector2 value)
+		{
+			Fix64 val = Fix64.One / Fix64.Sqrt((value.X * value.X) + (value.Y * value.Y));
+			value.X *= val;
+			value.Y *= val;
+			return value;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains reflect vector of the given vector and normal.
+		/// </summary>
+		/// <param name="vector">Source <see cref="Vector2"/>.</param>
+		/// <param name="normal">Reflection normal.</param>
+		/// <returns>Reflected vector.</returns>
+		public static Vector2 Reflect(Vector2 vector, Vector2 normal)
+		{
+			Vector2 result;
+			Fix64 val = new Fix64(2) * ((vector.X * normal.X) + (vector.Y * normal.Y));
+			result.X = vector.X - (normal.X * val);
+			result.Y = vector.Y - (normal.Y * val);
+			return result;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains subtraction of on <see cref="Vector2"/> from a another.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/>.</param>
+		/// <param name="value2">Source <see cref="Vector2"/>.</param>
+		/// <returns>The result of the vector subtraction.</returns>
+		public static Vector2 Subtract(Vector2 value1, Vector2 value2)
+		{
+			value1.X -= value2.X;
+			value1.Y -= value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of 2d-vector by the specified <see cref="Matrix4x4"/>.
+		/// </summary>
+		/// <param name="position">Source <see cref="Vector2"/>.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix4x4"/>.</param>
+		/// <returns>Transformed <see cref="Vector2"/>.</returns>
+		public static Vector2 Transform(Vector2 position, Matrix4x4 matrix)
+		{
+			return new Vector2(
+				(position.X * matrix.M11) + (position.Y * matrix.M21) + matrix.M41,
+				(position.X * matrix.M12) + (position.Y * matrix.M22) + matrix.M42
+			);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of 2d-vector by the specified <see cref="Quaternion"/>, representing the rotation.
+		/// </summary>
+		/// <param name="value">Source <see cref="Vector2"/>.</param>
+		/// <param name="rotation">The <see cref="Quaternion"/> which contains rotation transformation.</param>
+		/// <returns>Transformed <see cref="Vector2"/>.</returns>
+		public static Vector2 Transform(Vector2 value, Quaternion rotation)
+		{
+			Transform(ref value, ref rotation, out value);
+			return value;
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of 2d-vector by the specified <see cref="Quaternion"/>, representing the rotation.
+		/// </summary>
+		/// <param name="value">Source <see cref="Vector2"/>.</param>
+		/// <param name="rotation">The <see cref="Quaternion"/> which contains rotation transformation.</param>
+		/// <param name="result">Transformed <see cref="Vector2"/> as an output parameter.</param>
+		public static void Transform(
+			ref Vector2 value,
+			ref Quaternion rotation,
+			out Vector2 result
+		)
+		{
+			Fix64 two = new Fix64(2);
+			Fix64 x = two * -(rotation.Z * value.Y);
+			Fix64 y = two * (rotation.Z * value.X);
+			Fix64 z = two * (rotation.X * value.Y - rotation.Y * value.X);
+
+			result.X = value.X + x * rotation.W + (rotation.Y * z - rotation.Z * y);
+			result.Y = value.Y + y * rotation.W + (rotation.Z * x - rotation.X * z);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of 2d-vector by the specified <see cref="Math.Matrix3x2"/>.
+		/// </summary>
+		/// <param name="position">Source <see cref="Vector2"/>.</param>
+		/// <param name="matrix">The transformation <see cref="Math.Matrix3x2"/>.</param>
+		/// <returns>Transformed <see cref="Vector2"/>.</returns>
+		public static Vector2 Transform(Vector2 position, Matrix3x2 matrix)
+		{
+			return new Vector2(
+				(position.X * matrix.M11) + (position.Y * matrix.M21) + matrix.M31,
+				(position.X * matrix.M12) + (position.Y * matrix.M22) + matrix.M32
+			);
+		}
+
+		/// <summary>
+		/// Apply transformation on all vectors within array of <see cref="Vector2"/> by the specified <see cref="Matrix4x4"/> and places the results in an another array.
+		/// </summary>
+		/// <param name="sourceArray">Source array.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix4x4"/>.</param>
+		/// <param name="destinationArray">Destination array.</param>
+		public static void Transform(
+			Vector2[] sourceArray,
+			ref Matrix4x4 matrix,
+			Vector2[] destinationArray
+		)
+		{
+			Transform(sourceArray, 0, ref matrix, destinationArray, 0, sourceArray.Length);
+		}
+
+		/// <summary>
+		/// Apply transformation on vectors within array of <see cref="Vector2"/> by the specified <see cref="Matrix4x4"/> and places the results in an another array.
+		/// </summary>
+		/// <param name="sourceArray">Source array.</param>
+		/// <param name="sourceIndex">The starting index of transformation in the source array.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix4x4"/>.</param>
+		/// <param name="destinationArray">Destination array.</param>
+		/// <param name="destinationIndex">The starting index in the destination array, where the first <see cref="Vector2"/> should be written.</param>
+		/// <param name="length">The number of vectors to be transformed.</param>
+		public static void Transform(
+			Vector2[] sourceArray,
+			int sourceIndex,
+			ref Matrix4x4 matrix,
+			Vector2[] destinationArray,
+			int destinationIndex,
+			int length
+		)
+		{
+			for (int x = 0; x < length; x += 1)
+			{
+				Vector2 position = sourceArray[sourceIndex + x];
+				Vector2 destination = destinationArray[destinationIndex + x];
+				destination.X = (position.X * matrix.M11) + (position.Y * matrix.M21)
+						+ matrix.M41;
+				destination.Y = (position.X * matrix.M12) + (position.Y * matrix.M22)
+						+ matrix.M42;
+				destinationArray[destinationIndex + x] = destination;
+			}
+		}
+
+		/// <summary>
+		/// Apply transformation on all vectors within array of <see cref="Vector2"/> by the specified <see cref="Quaternion"/> and places the results in an another array.
+		/// </summary>
+		/// <param name="sourceArray">Source array.</param>
+		/// <param name="rotation">The <see cref="Quaternion"/> which contains rotation transformation.</param>
+		/// <param name="destinationArray">Destination array.</param>
+		public static void Transform(
+			Vector2[] sourceArray,
+			ref Quaternion rotation,
+			Vector2[] destinationArray
+		)
+		{
+			Transform(
+				sourceArray,
+				0,
+				ref rotation,
+				destinationArray,
+				0,
+				sourceArray.Length
+			);
+		}
+
+		/// <summary>
+		/// Apply transformation on vectors within array of <see cref="Vector2"/> by the specified <see cref="Quaternion"/> and places the results in an another array.
+		/// </summary>
+		/// <param name="sourceArray">Source array.</param>
+		/// <param name="sourceIndex">The starting index of transformation in the source array.</param>
+		/// <param name="rotation">The <see cref="Quaternion"/> which contains rotation transformation.</param>
+		/// <param name="destinationArray">Destination array.</param>
+		/// <param name="destinationIndex">The starting index in the destination array, where the first <see cref="Vector2"/> should be written.</param>
+		/// <param name="length">The number of vectors to be transformed.</param>
+		public static void Transform(
+			Vector2[] sourceArray,
+			int sourceIndex,
+			ref Quaternion rotation,
+			Vector2[] destinationArray,
+			int destinationIndex,
+			int length
+		)
+		{
+			for (int i = 0; i < length; i += 1)
+			{
+				Vector2 position = sourceArray[sourceIndex + i];
+				Vector2 v;
+				Transform(ref position, ref rotation, out v);
+				destinationArray[destinationIndex + i] = v;
+			}
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of the specified normal by the specified <see cref="Matrix4x4"/>.
+		/// </summary>
+		/// <param name="normal">Source <see cref="Vector2"/> which represents a normal vector.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix4x4"/>.</param>
+		/// <returns>Transformed normal.</returns>
+		public static Vector2 TransformNormal(Vector2 normal, Matrix4x4 matrix)
+		{
+			return new Vector2(
+				(normal.X * matrix.M11) + (normal.Y * matrix.M21),
+				(normal.X * matrix.M12) + (normal.Y * matrix.M22)
+			);
+		}
+
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of the specified normal by the specified <see cref="Math.Matrix3x2"/>.
+		/// </summary>
+		/// <param name="normal">Source <see cref="Vector2"/> which represents a normal vector.</param>
+		/// <param name="matrix">The transformation <see cref="Math.Matrix3x2"/>.</param>
+		/// <returns>Transformed normal.</returns>
+		public static Vector2 TransformNormal(Vector2 normal, Matrix3x2 matrix)
+        {
+            return new Vector2(
+                normal.X * matrix.M11 + normal.Y * matrix.M21,
+                normal.X * matrix.M12 + normal.Y * matrix.M22);
+        }
+
+		/// <summary>
+		/// Apply transformation on all normals within array of <see cref="Vector2"/> by the specified <see cref="Matrix4x4"/> and places the results in an another array.
+		/// </summary>
+		/// <param name="sourceArray">Source array.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix4x4"/>.</param>
+		/// <param name="destinationArray">Destination array.</param>
+		public static void TransformNormal(
+			Vector2[] sourceArray,
+			ref Matrix4x4 matrix,
+			Vector2[] destinationArray
+		)
+		{
+			TransformNormal(
+				sourceArray,
+				0,
+				ref matrix,
+				destinationArray,
+				0,
+				sourceArray.Length
+			);
+		}
+
+		/// <summary>
+		/// Apply transformation on normals within array of <see cref="Vector2"/> by the specified <see cref="Matrix4x4"/> and places the results in an another array.
+		/// </summary>
+		/// <param name="sourceArray">Source array.</param>
+		/// <param name="sourceIndex">The starting index of transformation in the source array.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix4x4"/>.</param>
+		/// <param name="destinationArray">Destination array.</param>
+		/// <param name="destinationIndex">The starting index in the destination array, where the first <see cref="Vector2"/> should be written.</param>
+		/// <param name="length">The number of normals to be transformed.</param>
+		public static void TransformNormal(
+			Vector2[] sourceArray,
+			int sourceIndex,
+			ref Matrix4x4 matrix,
+			Vector2[] destinationArray,
+			int destinationIndex,
+			int length
+		)
+		{
+			for (int i = 0; i < length; i += 1)
+			{
+				Vector2 position = sourceArray[sourceIndex + i];
+				Vector2 result;
+				result.X = (position.X * matrix.M11) + (position.Y * matrix.M21);
+				result.Y = (position.X * matrix.M12) + (position.Y * matrix.M22);
+				destinationArray[destinationIndex + i] = result;
+			}
+		}
+
+		/// <summary>
+		/// Rotates a Vector2 by an angle.
+		/// </summary>
+		/// <param name="vector">The vector to rotate.</param>
+		/// <param name="angle">The angle in radians.</param>
+		public static Vector2 Rotate(Vector2 vector, Fix64 angle)
+		{
+			return new Vector2(
+				vector.X * Fix64.Cos(angle) - vector.Y * Fix64.Sin(angle),
+				vector.X * Fix64.Sin(angle) + vector.Y * Fix64.Cos(angle)
+			);
+		}
+
+		#endregion
+
+		#region Public Static Operators
+
+		/// <summary>
+		/// Inverts values in the specified <see cref="Vector2"/>.
+		/// </summary>
+		/// <param name="value">Source <see cref="Vector2"/> on the right of the sub sign.</param>
+		/// <returns>Result of the inversion.</returns>
+		public static Vector2 operator -(Vector2 value)
+		{
+			value.X = -value.X;
+			value.Y = -value.Y;
+			return value;
+		}
+
+		/// <summary>
+		/// Compares whether two <see cref="Vector2"/> instances are equal.
+		/// </summary>
+		/// <param name="value1"><see cref="Vector2"/> instance on the left of the equal sign.</param>
+		/// <param name="value2"><see cref="Vector2"/> instance on the right of the equal sign.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public static bool operator ==(Vector2 value1, Vector2 value2)
+		{
+			return (value1.X == value2.X &&
+					value1.Y == value2.Y);
+		}
+
+		/// <summary>
+		/// Compares whether two <see cref="Vector2"/> instances are equal.
+		/// </summary>
+		/// <param name="value1"><see cref="Vector2"/> instance on the left of the equal sign.</param>
+		/// <param name="value2"><see cref="Vector2"/> instance on the right of the equal sign.</param>
+		/// <returns><c>true</c> if the instances are equal; <c>false</c> otherwise.</returns>
+		public static bool operator !=(Vector2 value1, Vector2 value2)
+		{
+			return !(value1 == value2);
+		}
+
+		/// <summary>
+		/// Adds two vectors.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/> on the left of the add sign.</param>
+		/// <param name="value2">Source <see cref="Vector2"/> on the right of the add sign.</param>
+		/// <returns>Sum of the vectors.</returns>
+		public static Vector2 operator +(Vector2 value1, Vector2 value2)
+		{
+			value1.X += value2.X;
+			value1.Y += value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Subtracts a <see cref="Vector2"/> from a <see cref="Vector2"/>.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/> on the left of the sub sign.</param>
+		/// <param name="value2">Source <see cref="Vector2"/> on the right of the sub sign.</param>
+		/// <returns>Result of the vector subtraction.</returns>
+		public static Vector2 operator -(Vector2 value1, Vector2 value2)
+		{
+			value1.X -= value2.X;
+			value1.Y -= value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Multiplies the components of two vectors by each other.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/> on the left of the mul sign.</param>
+		/// <param name="value2">Source <see cref="Vector2"/> on the right of the mul sign.</param>
+		/// <returns>Result of the vector multiplication.</returns>
+		public static Vector2 operator *(Vector2 value1, Vector2 value2)
+		{
+			value1.X *= value2.X;
+			value1.Y *= value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Multiplies the components of vector by a scalar.
+		/// </summary>
+		/// <param name="value">Source <see cref="Vector2"/> on the left of the mul sign.</param>
+		/// <param name="scaleFactor">Scalar value on the right of the mul sign.</param>
+		/// <returns>Result of the vector multiplication with a scalar.</returns>
+		public static Vector2 operator *(Vector2 value, Fix64 scaleFactor)
+		{
+			value.X *= scaleFactor;
+			value.Y *= scaleFactor;
+			return value;
+		}
+
+		/// <summary>
+		/// Multiplies the components of vector by a scalar.
+		/// </summary>
+		/// <param name="scaleFactor">Scalar value on the left of the mul sign.</param>
+		/// <param name="value">Source <see cref="Vector2"/> on the right of the mul sign.</param>
+		/// <returns>Result of the vector multiplication with a scalar.</returns>
+		public static Vector2 operator *(Fix64 scaleFactor, Vector2 value)
+		{
+			value.X *= scaleFactor;
+			value.Y *= scaleFactor;
+			return value;
+		}
+
+		/// <summary>
+		/// Divides the components of a <see cref="Vector2"/> by the components of another <see cref="Vector2"/>.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/> on the left of the div sign.</param>
+		/// <param name="value2">Divisor <see cref="Vector2"/> on the right of the div sign.</param>
+		/// <returns>The result of dividing the vectors.</returns>
+		public static Vector2 operator /(Vector2 value1, Vector2 value2)
+		{
+			value1.X /= value2.X;
+			value1.Y /= value2.Y;
+			return value1;
+		}
+
+		/// <summary>
+		/// Divides the components of a <see cref="Vector2"/> by a scalar.
+		/// </summary>
+		/// <param name="value1">Source <see cref="Vector2"/> on the left of the div sign.</param>
+		/// <param name="divider">Divisor scalar on the right of the div sign.</param>
+		/// <returns>The result of dividing a vector by a scalar.</returns>
+		public static Vector2 operator /(Vector2 value1, Fix64 divider)
+		{
+			Fix64 factor = Fix64.One / divider;
+			value1.X *= factor;
+			value1.Y *= factor;
+			return value1;
+		}
+
+		#endregion
+	}
+}

src/Math/Float/BoundingBox.cs

@@ -21,7 +21,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	[Serializable]
 	[DebuggerDisplay("{DebugDisplayString,nq}")]

src/Math/Float/BoundingFrustum.cs

@@ -20,7 +20,7 @@ using System.Diagnostics;
 using System.Text;
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Defines a viewing frustum for intersection operations.

src/Math/Float/BoundingSphere.cs

@@ -21,7 +21,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Describes a sphere in 3D-space for bounding operations.

src/Math/Float/ContainmentType.cs

@@ -14,7 +14,7 @@
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Defines how the bounding volumes intersects or contain one another.

src/Math/Float/Matrix3x2.cs

@@ -10,7 +10,7 @@
 using System;
 using System.Globalization;
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// A structure encapsulating a 3x2 matrix.

src/Math/Float/Matrix4x4.cs

@@ -21,7 +21,7 @@ using System.Runtime.InteropServices;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Represents the right-handed 4x4 floating point matrix, which can store translation, scale and rotation information.

src/Math/Float/Plane.cs

@@ -20,7 +20,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	[Serializable]
 	[DebuggerDisplay("{DebugDisplayString,nq}")]

src/Math/Float/PlaneIntersectionType.cs

@@ -14,7 +14,7 @@
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Defines the intersection between a <see cref="Plane"/> and a bounding volume.

src/Math/Float/Point.cs

@@ -20,7 +20,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Describes a 2D-point.

src/Math/Float/Quaternion.cs

@@ -20,7 +20,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// An efficient mathematical representation for three dimensional rotations.

src/Math/Float/Ray.cs

@@ -20,7 +20,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	[Serializable]
 	[DebuggerDisplay("{DebugDisplayString,nq}")]

src/Math/Float/Rectangle.cs

@@ -20,7 +20,7 @@ using System.Diagnostics;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Describes a 2D-rectangle.

src/Math/Float/Transform2D.cs

@@ -0,0 +1,105 @@
+namespace MoonWorks.Math.Float
+{
+	public struct Transform2D : System.IEquatable<Transform2D>
+	{
+		public Vector2 Position { get; }
+		public float Rotation { get; }
+		public Vector2 Scale { get; }
+
+		private bool transformMatrixCalculated;
+		private Matrix3x2 transformMatrix;
+
+		public Matrix3x2 TransformMatrix
+		{
+			get
+			{
+				if (!transformMatrixCalculated)
+				{
+					transformMatrix = CreateTransformMatrix(Position, Rotation, Scale);
+					transformMatrixCalculated = true;
+				}
+
+				return transformMatrix;
+			}
+		}
+
+		public bool IsAxisAligned => Rotation % MathHelper.PiOver2 == 0;
+		public bool IsUniformScale => Scale.X == Scale.Y;
+
+		public static readonly Transform2D Identity = new Transform2D(Vector2.Zero, 0, Vector2.One);
+
+		public Transform2D(Vector2 position)
+		{
+			Position = position;
+			Rotation = 0;
+			Scale = Vector2.One;
+			transformMatrixCalculated = false;
+			transformMatrix = Matrix3x2.Identity;
+		}
+
+		public Transform2D(Vector2 position, float rotation)
+		{
+			Position = position;
+			Rotation = rotation;
+			Scale = Vector2.One;
+			transformMatrixCalculated = false;
+			transformMatrix = Matrix3x2.Identity;
+		}
+
+		public Transform2D(Vector2 position, float rotation, Vector2 scale)
+		{
+			Position = position;
+			Rotation = rotation;
+			Scale = scale;
+			transformMatrixCalculated = false;
+			transformMatrix = Matrix3x2.Identity;
+		}
+
+		public Transform2D Compose(Transform2D other)
+		{
+			return new Transform2D(Position + other.Position, Rotation + other.Rotation, Scale * other.Scale);
+		}
+
+		private static Matrix3x2 CreateTransformMatrix(Vector2 position, float rotation, Vector2 scale)
+		{
+			return
+				Matrix3x2.CreateScale(scale) *
+				Matrix3x2.CreateRotation(rotation) *
+				Matrix3x2.CreateTranslation(position);
+		}
+
+		public bool Equals(Transform2D other)
+		{
+			return
+				Position == other.Position &&
+				Rotation == other.Rotation &&
+				Scale == other.Scale;
+		}
+
+
+        public override bool Equals(System.Object other)
+        {
+            if (other is Transform2D otherTransform)
+            {
+                return Equals(otherTransform);
+            }
+
+            return false;
+        }
+
+		public override int GetHashCode()
+		{
+			return System.HashCode.Combine(Position, Rotation, Scale);
+		}
+
+		public static bool operator ==(Transform2D a, Transform2D b)
+		{
+			return a.Equals(b);
+		}
+
+		public static bool operator !=(Transform2D a, Transform2D b)
+		{
+			return !a.Equals(b);
+		}
+	}
+}

src/Math/Float/Vector2.cs

@@ -21,7 +21,7 @@ using System.Runtime.InteropServices;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Describes a 2D-vector.
@@ -204,6 +204,14 @@ namespace MoonWorks.Math
 			Y *= val;
 		}
 
+		/// <summary>
+		/// Turns this <see cref="Vector2"/> to an angle in radians.
+		/// </summary>
+		public float Angle()
+		{
+			return MathF.Atan2(Y, X);
+		}
+
 		/// <summary>
 		/// Returns a <see cref="String"/> representation of this <see cref="Vector2"/> in the format:
 		/// {X:[<see cref="X"/>] Y:[<see cref="Y"/>]}
@@ -877,6 +885,20 @@ namespace MoonWorks.Math
 			result.Y = value.Y + y * rotation.W + (rotation.Z * x - rotation.X * z);
 		}
 
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of 2d-vector by the specified <see cref="Matrix3x2"/>.
+		/// </summary>
+		/// <param name="position">Source <see cref="Vector2"/>.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix3x2"/>.</param>
+		/// <returns>Transformed <see cref="Vector2"/>.</returns>
+		public static Vector2 Transform(Vector2 position, Matrix3x2 matrix)
+		{
+			return new Vector2(
+				(position.X * matrix.M11) + (position.Y * matrix.M21) + matrix.M31,
+				(position.X * matrix.M12) + (position.Y * matrix.M22) + matrix.M32
+			);
+		}
+
 		/// <summary>
 		/// Apply transformation on all vectors within array of <see cref="Vector2"/> by the specified <see cref="Matrix4x4"/> and places the results in an another array.
 		/// </summary>
@@ -985,6 +1007,19 @@ namespace MoonWorks.Math
 			);
 		}
 
+		/// <summary>
+		/// Creates a new <see cref="Vector2"/> that contains a transformation of the specified normal by the specified <see cref="Matrix3x2"/>.
+		/// </summary>
+		/// <param name="normal">Source <see cref="Vector2"/> which represents a normal vector.</param>
+		/// <param name="matrix">The transformation <see cref="Matrix3x2"/>.</param>
+		/// <returns>Transformed normal.</returns>
+        public static Vector2 TransformNormal(Vector2 normal, Matrix3x2 matrix)
+        {
+            return new Vector2(
+                normal.X * matrix.M11 + normal.Y * matrix.M21,
+                normal.X * matrix.M12 + normal.Y * matrix.M22);
+        }
+
 		/// <summary>
 		/// Creates a new <see cref="Vector2"/> that contains a transformation of the specified normal by the specified <see cref="Matrix4x4"/>.
 		/// </summary>
@@ -1053,6 +1088,19 @@ namespace MoonWorks.Math
 			}
 		}
 
+		/// <summary>
+		/// Rotates a Vector2 by an angle.
+		/// </summary>
+		/// <param name="vector">The vector to rotate.</param>
+		/// <param name="angle">The angle in radians.</param>
+		public static Vector2 Rotate(Vector2 vector, float angle)
+		{
+			return new Vector2(
+				vector.X * (float) System.Math.Cos(angle) - vector.Y * (float) System.Math.Sin(angle),
+				vector.X * (float) System.Math.Sin(angle) + vector.Y * (float) System.Math.Cos(angle)
+			);
+		}
+
 		#endregion
 
 		#region Public Static Operators

src/Math/Float/Vector3.cs

@@ -22,7 +22,7 @@ using System.Text;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Describes a 3D-vector.

src/Math/Float/Vector4.cs

@@ -21,7 +21,7 @@ using System.Runtime.InteropServices;
 
 #endregion
 
-namespace MoonWorks.Math
+namespace MoonWorks.Math.Float
 {
 	/// <summary>
 	/// Describes a 4D-vector.

src/Math/MathHelper.cs

@@ -280,6 +280,11 @@ namespace MoonWorks.Math
 			return result;
 		}
 
+		public static float Quantize(float value, float step)
+		{
+			return (float) System.Math.Floor(value / step) * step;
+		}
+
 		/// <summary>
 		/// Converts radians to degrees.
 		/// </summary>
@@ -331,6 +336,61 @@ namespace MoonWorks.Math
 			return angle;
 		}
 
+		/// <summary>
+		/// Rescales a value within a given range to a new range.
+		/// </summary>
+		public static float Normalize(short value, short min, short max, short newMin, short newMax)
+		{
+			return ((float) (value - min) * (newMax - newMin)) / (max - min) + newMin;
+		}
+
+		/// <summary>
+		/// Rescales a value within a given range to a new range.
+		/// </summary>
+		public static float Normalize(float value, float min, float max, float newMin, float newMax)
+		{
+			return ((value - min) * (newMax - newMin)) / (max - min) + newMin;
+		}
+
+		/// <summary>
+        /// Step from start towards end by change.
+        /// </summary>
+        /// <param name="start">Start value.</param>
+        /// <param name="end">End value.</param>
+        /// <param name="change">Change value.</param>
+        public static float Approach(float start, float end, float change)
+        {
+            return start < end ?
+                System.Math.Min(start + change, end) :
+                System.Math.Max(start - change, end);
+        }
+
+		/// <summary>
+        /// Step from start towards end by change.
+        /// </summary>
+        /// <param name="start">Start value.</param>
+        /// <param name="end">End value.</param>
+        /// <param name="change">Change value.</param>
+		public static int Approach(int start, int end, int change)
+		{
+			return start < end ?
+                System.Math.Min(start + change, end) :
+                System.Math.Max(start - change, end);
+		}
+
+		/// <summary>
+        /// Step from start towards end by change.
+        /// </summary>
+        /// <param name="start">Start value.</param>
+        /// <param name="end">End value.</param>
+        /// <param name="change">Change value.</param>
+        public static Fixed.Fix64 Approach(Fixed.Fix64 start, Fixed.Fix64 end, Fixed.Fix64 change)
+        {
+            return start < end ?
+                Fixed.Fix64.Min(start + change, end) :
+                Fixed.Fix64.Max(start - change, end);
+        }
+
 		#endregion
 
 		#region Internal Static Methods

src/MoonWorksDllMap.cs

@@ -195,6 +195,8 @@ namespace MoonWorks
 			NativeLibrary.SetDllImportResolver(typeof(SDL2.SDL).Assembly, MapAndLoad);
 			NativeLibrary.SetDllImportResolver(typeof(RefreshCS.Refresh).Assembly, MapAndLoad);
 			NativeLibrary.SetDllImportResolver(typeof(FAudio).Assembly, MapAndLoad);
+			NativeLibrary.SetDllImportResolver(typeof(WellspringCS.Wellspring).Assembly, MapAndLoad);
+			NativeLibrary.SetDllImportResolver(typeof(Theorafile).Assembly, MapAndLoad);
 		}
 
 		#endregion

src/ScreenMode.cs

@@ -1,4 +1,4 @@
-namespace MoonWorks.Window
+namespace MoonWorks
 {
 	public enum ScreenMode
 	{

src/Video/Shaders/Source/Fullscreen.vert

@@ -0,0 +1,9 @@
+#version 450
+
+layout(location = 0) out vec2 outTexCoord;
+
+void main()
+{
+	outTexCoord = vec2((gl_VertexIndex << 1) & 2, gl_VertexIndex & 2);
+	gl_Position = vec4(outTexCoord * 2.0 - 1.0, 0.0, 1.0);
+}

src/Video/Shaders/Source/YUV2RGBA.frag

@@ -0,0 +1,38 @@
+/*
+ * This effect is based on the YUV-to-RGBA GLSL shader found in SDL.
+ * Thus, it also released under the zlib license:
+ * http://libsdl.org/license.php
+ */
+#version 450
+
+layout(location = 0) in vec2 TexCoord;
+
+layout(location = 0) out vec4 FragColor;
+
+layout(binding = 0, set = 1) uniform sampler2D YSampler;
+layout(binding = 1, set = 1) uniform sampler2D USampler;
+layout(binding = 2, set = 1) uniform sampler2D VSampler;
+
+/* More info about colorspace conversion:
+ * http://www.equasys.de/colorconversion.html
+ * http://www.equasys.de/colorformat.html
+ */
+
+const vec3 offset = vec3(-0.0625, -0.5, -0.5);
+const vec3 Rcoeff = vec3(1.164,  0.000,  1.793);
+const vec3 Gcoeff = vec3(1.164, -0.213, -0.533);
+const vec3 Bcoeff = vec3(1.164,  2.112,  0.000);
+
+void main()
+{
+	vec3 yuv;
+	yuv.x = texture(YSampler, TexCoord).r;
+	yuv.y = texture(USampler, TexCoord).r;
+	yuv.z = texture(VSampler, TexCoord).r;
+	yuv += offset;
+
+	FragColor.r = dot(yuv, Rcoeff);
+	FragColor.g = dot(yuv, Gcoeff);
+	FragColor.b = dot(yuv, Bcoeff);
+	FragColor.a = 1.0;
+}

src/Video/StreamingSoundTheora.cs

@@ -0,0 +1,45 @@
+using System;
+using MoonWorks.Audio;
+
+namespace MoonWorks.Video
+{
+	public unsafe class StreamingSoundTheora : StreamingSound
+	{
+		private IntPtr VideoHandle;
+		protected override int BUFFER_SIZE => 8192;
+
+		internal StreamingSoundTheora(
+			AudioDevice device,
+			IntPtr videoHandle,
+			int channels,
+			uint sampleRate
+		) : base(
+			device,
+			3, /* float type */
+			32, /* size of float */
+			(ushort) (4 * channels),
+			(ushort) channels,
+			sampleRate
+		) {
+			VideoHandle = videoHandle;
+		}
+
+		protected override unsafe void FillBuffer(
+			void* buffer,
+			int bufferLengthInBytes,
+			out int filledLengthInBytes,
+			out bool reachedEnd
+		) {
+			var lengthInFloats = bufferLengthInBytes / sizeof(float);
+
+			int samples = Theorafile.tf_readaudio(
+				VideoHandle,
+				(IntPtr) buffer,
+				lengthInFloats
+			);
+
+			filledLengthInBytes = samples * sizeof(float);
+			reachedEnd = Theorafile.tf_eos(VideoHandle) == 1;
+		}
+	}
+}

src/Video/Video.cs

@@ -0,0 +1,357 @@
+/* Heavily based on https://github.com/FNA-XNA/FNA/blob/master/src/Media/Xiph/VideoPlayer.cs */
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using MoonWorks.Audio;
+using MoonWorks.Graphics;
+
+namespace MoonWorks.Video
+{
+	public enum VideoState
+	{
+		Playing,
+		Paused,
+		Stopped
+	}
+
+	public unsafe class Video : IDisposable
+	{
+		internal IntPtr Handle;
+
+		public bool Loop { get; private set; }
+		public float Volume {
+			get => volume;
+			set
+			{
+				volume = value;
+				if (audioStream != null)
+				{
+					audioStream.Volume = value;
+				}
+			}
+		}
+		public float PlaybackSpeed { get; set; }
+		public double FramesPerSecond => fps;
+		private VideoState State = VideoState.Stopped;
+
+		private double fps;
+		private int yWidth;
+		private int yHeight;
+		private int uvWidth;
+		private int uvHeight;
+
+		private void* yuvData = null;
+		private int yuvDataLength;
+		private int currentFrame;
+
+		private GraphicsDevice GraphicsDevice;
+		private Texture RenderTexture = null;
+		private Texture yTexture = null;
+		private Texture uTexture = null;
+		private Texture vTexture = null;
+		private Sampler LinearSampler;
+
+		private AudioDevice AudioDevice = null;
+		private StreamingSoundTheora audioStream = null;
+		private float volume = 1.0f;
+
+		private Stopwatch timer;
+		private double lastTimestamp;
+		private double timeElapsed;
+
+		private bool disposed;
+
+		/* TODO: is there some way for us to load the data into memory? */
+		public Video(GraphicsDevice graphicsDevice, AudioDevice audioDevice, string filename)
+		{
+			GraphicsDevice = graphicsDevice;
+			AudioDevice = audioDevice;
+
+			if (!System.IO.File.Exists(filename))
+			{
+				throw new ArgumentException("Video file not found!");
+			}
+
+			if (Theorafile.tf_fopen(filename, out Handle) < 0)
+			{
+				throw new ArgumentException("Invalid video file!");
+			}
+
+			Theorafile.th_pixel_fmt format;
+			Theorafile.tf_videoinfo(
+				Handle,
+				out yWidth,
+				out yHeight,
+				out fps,
+				out format
+			);
+
+			if (format == Theorafile.th_pixel_fmt.TH_PF_420)
+			{
+				uvWidth = yWidth / 2;
+				uvHeight = yHeight / 2;
+			}
+			else if (format == Theorafile.th_pixel_fmt.TH_PF_422)
+			{
+				uvWidth = yWidth / 2;
+				uvHeight = yHeight;
+			}
+			else if (format == Theorafile.th_pixel_fmt.TH_PF_444)
+			{
+				uvWidth = yWidth;
+				uvHeight = yHeight;
+			}
+			else
+			{
+				throw new NotSupportedException("Unrecognized YUV format!");
+			}
+
+			yuvDataLength = (
+				(yWidth * yHeight) +
+				(uvWidth * uvHeight * 2)
+			);
+
+			yuvData = NativeMemory.Alloc((nuint) yuvDataLength);
+
+			InitializeTheoraStream();
+
+			if (Theorafile.tf_hasvideo(Handle) == 1)
+			{
+				RenderTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) yWidth,
+					(uint) yHeight,
+					TextureFormat.R8G8B8A8,
+					TextureUsageFlags.ColorTarget | TextureUsageFlags.Sampler
+				);
+
+				yTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) yWidth,
+					(uint) yHeight,
+					TextureFormat.R8,
+					TextureUsageFlags.Sampler
+				);
+
+				uTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) uvWidth,
+					(uint) uvHeight,
+					TextureFormat.R8,
+					TextureUsageFlags.Sampler
+				);
+
+				vTexture = Texture.CreateTexture2D(
+					GraphicsDevice,
+					(uint) uvWidth,
+					(uint) uvHeight,
+					TextureFormat.R8,
+					TextureUsageFlags.Sampler
+				);
+
+				LinearSampler = new Sampler(GraphicsDevice, SamplerCreateInfo.LinearClamp);
+			}
+
+			timer = new Stopwatch();
+		}
+
+		public void Play(bool loop = false)
+		{
+			if (State == VideoState.Playing)
+			{
+				return;
+			}
+
+			Loop = loop;
+			timer.Start();
+
+			if (audioStream != null)
+			{
+				audioStream.Play();
+			}
+
+			State = VideoState.Playing;
+		}
+
+		public void Pause()
+		{
+			if (State != VideoState.Playing)
+			{
+				return;
+			}
+
+			timer.Stop();
+
+			if (audioStream != null)
+			{
+				audioStream.Pause();
+			}
+
+			State = VideoState.Paused;
+		}
+
+		public void Stop()
+		{
+			if (State == VideoState.Stopped)
+			{
+				return;
+			}
+
+			timer.Stop();
+			timer.Reset();
+
+			Theorafile.tf_reset(Handle);
+			lastTimestamp = 0;
+			timeElapsed = 0;
+
+			if (audioStream != null)
+			{
+				audioStream.StopImmediate();
+				audioStream.Dispose();
+				audioStream = null;
+			}
+
+			State = VideoState.Stopped;
+		}
+
+		public Texture GetTexture()
+		{
+			if (RenderTexture == null)
+			{
+				throw new InvalidOperationException();
+			}
+
+			if (State == VideoState.Stopped)
+			{
+				return RenderTexture;
+			}
+
+			timeElapsed += (timer.Elapsed.TotalMilliseconds - lastTimestamp) * PlaybackSpeed;
+			lastTimestamp = timer.Elapsed.TotalMilliseconds;
+
+			int thisFrame = ((int) (timeElapsed / (1000.0 / FramesPerSecond)));
+			if (thisFrame > currentFrame)
+			{
+				if (Theorafile.tf_readvideo(
+					Handle,
+					(IntPtr) yuvData,
+					thisFrame - currentFrame
+				) == 1 || currentFrame == -1) {
+					UpdateTexture();
+				}
+
+				currentFrame = thisFrame;
+			}
+
+			bool ended = Theorafile.tf_eos(Handle) == 1;
+			if (ended)
+			{
+				timer.Stop();
+				timer.Reset();
+
+				if (audioStream != null)
+				{
+					audioStream.Stop();
+					audioStream.Dispose();
+					audioStream = null;
+				}
+
+				Theorafile.tf_reset(Handle);
+
+				if (Loop)
+				{
+					// Start over!
+					InitializeTheoraStream();
+
+					timer.Start();
+				}
+				else
+				{
+					State = VideoState.Stopped;
+				}
+			}
+
+			return RenderTexture;
+		}
+
+		private void UpdateTexture()
+		{
+			var commandBuffer = GraphicsDevice.AcquireCommandBuffer();
+
+			commandBuffer.SetTextureDataYUV(
+				yTexture,
+				uTexture,
+				vTexture,
+				(IntPtr) yuvData,
+				(uint) yuvDataLength
+			);
+
+			commandBuffer.BeginRenderPass(
+				new ColorAttachmentInfo(RenderTexture, Color.Black)
+			);
+
+			commandBuffer.BindGraphicsPipeline(GraphicsDevice.VideoPipeline);
+			commandBuffer.BindFragmentSamplers(
+				new TextureSamplerBinding(yTexture, LinearSampler),
+				new TextureSamplerBinding(uTexture, LinearSampler),
+				new TextureSamplerBinding(vTexture, LinearSampler)
+			);
+
+			commandBuffer.DrawPrimitives(0, 1, 0, 0);
+
+			commandBuffer.EndRenderPass();
+
+			GraphicsDevice.Submit(commandBuffer);
+		}
+
+		private void InitializeTheoraStream()
+		{
+			// Grab the first video frame ASAP.
+			while (Theorafile.tf_readvideo(Handle, (IntPtr) yuvData, 1) == 0);
+
+			// Grab the first bit of audio. We're trying to start the decoding ASAP.
+			if (AudioDevice != null && Theorafile.tf_hasaudio(Handle) == 1)
+			{
+				int channels, sampleRate;
+				Theorafile.tf_audioinfo(Handle, out channels, out sampleRate);
+				audioStream = new StreamingSoundTheora(AudioDevice, Handle, channels, (uint) sampleRate);
+			}
+
+			currentFrame = -1;
+		}
+
+		protected virtual void Dispose(bool disposing)
+		{
+			if (!disposed)
+			{
+				if (disposing)
+				{
+					// dispose managed state (managed objects)
+					RenderTexture.Dispose();
+					yTexture.Dispose();
+					uTexture.Dispose();
+					vTexture.Dispose();
+				}
+
+				// free unmanaged resources (unmanaged objects)
+				Theorafile.tf_close(ref Handle);
+				NativeMemory.Free(yuvData);
+
+				disposed = true;
+			}
+		}
+
+		~Video()
+		{
+		    // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+		    Dispose(disposing: false);
+		}
+
+		public void Dispose()
+		{
+			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+			Dispose(disposing: true);
+			GC.SuppressFinalize(this);
+		}
+	}
+}

src/Window.cs

@@ -1,18 +1,18 @@
 using System;
 using SDL2;
 
-namespace MoonWorks.Window
+namespace MoonWorks
 {
-	public class OSWindow : IDisposable
+	public class Window : IDisposable
 	{
 		internal IntPtr Handle { get; }
-		public ScreenMode ScreenMode { get; }
+		public ScreenMode ScreenMode { get; private set; }
-		public uint Width { get; }
+		public uint Width { get; private set; }
-		public uint Height { get; }
+		public uint Height { get; private set; }
 
 		private bool IsDisposed;
 
-		public OSWindow(WindowCreateInfo windowCreateInfo)
+		public Window(WindowCreateInfo windowCreateInfo)
 		{
 			var windowFlags = SDL.SDL_WindowFlags.SDL_WINDOW_VULKAN;
 
@@ -25,6 +25,16 @@ namespace MoonWorks.Window
 				windowFlags |= SDL.SDL_WindowFlags.SDL_WINDOW_FULLSCREEN_DESKTOP;
 			}
 
+			if (windowCreateInfo.SystemResizable)
+			{
+				windowFlags |= SDL.SDL_WindowFlags.SDL_WINDOW_RESIZABLE;
+			}
+
+			if (windowCreateInfo.StartMaximized)
+			{
+				windowFlags |= SDL.SDL_WindowFlags.SDL_WINDOW_MAXIMIZED;
+			}
+
 			ScreenMode = windowCreateInfo.ScreenMode;
 
 			Handle = SDL.SDL_CreateWindow(
@@ -53,6 +63,8 @@ namespace MoonWorks.Window
 				windowFlag = SDL.SDL_WindowFlags.SDL_WINDOW_FULLSCREEN_DESKTOP;
 			}
 
+			ScreenMode = screenMode;
+
 			SDL.SDL_SetWindowFullscreen(Handle, (uint) windowFlag);
 		}
 
@@ -65,6 +77,14 @@ namespace MoonWorks.Window
 		public void SetWindowSize(uint width, uint height)
 		{
 			SDL.SDL_SetWindowSize(Handle, (int) width, (int) height);
+			Width = width;
+			Height = height;
+		}
+
+		internal void SizeChanged(uint width, uint height)
+		{
+			Width = width;
+			Height = height;
 		}
 
 		protected virtual void Dispose(bool disposing)
@@ -82,7 +102,7 @@ namespace MoonWorks.Window
 			}
 		}
 
-		~OSWindow()
+		~Window()
 		{
 			// Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
 			Dispose(disposing: false);

src/Window/WindowCreateInfo.cs

@@ -1,10 +0,0 @@
-namespace MoonWorks.Window
-{
-	public struct WindowCreateInfo
-	{
-		public string WindowTitle;
-		public uint WindowWidth;
-		public uint WindowHeight;
-		public ScreenMode ScreenMode;
-	}
-}

src/WindowCreateInfo.cs

@@ -0,0 +1,28 @@
+namespace MoonWorks
+{
+	public struct WindowCreateInfo
+	{
+		public string WindowTitle;
+		public uint WindowWidth;
+		public uint WindowHeight;
+		public ScreenMode ScreenMode;
+		public bool SystemResizable;
+		public bool StartMaximized;
+
+		public WindowCreateInfo(
+			string windowTitle,
+			uint windowWidth,
+			uint windowHeight,
+			ScreenMode screenMode,
+			bool systemResizable = false,
+			bool startMaximized = false
+		) {
+			WindowTitle = windowTitle;
+			WindowWidth = windowWidth;
+			WindowHeight = windowHeight;
+			ScreenMode = screenMode;
+			SystemResizable = systemResizable;
+			StartMaximized = startMaximized;
+		}
+	}
+}