rework vertex input state creation to avoid reflection

src/Graphics/IVertexType.cs

@@ -0,0 +1,7 @@
+namespace MoonWorks.Graphics
+{
+	public interface IVertexType
+	{
+		VertexAttribute[] Attributes(uint binding = 0);
+	}
+}

src/Graphics/RefreshStructs.cs

@@ -127,12 +127,11 @@ namespace MoonWorks.Graphics
 		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
+		public static VertexBinding Create<T>(uint binding = 0) where T : unmanaged
 		{
 			return new VertexBinding
 			{
-				Binding = 0,
+				Binding = binding,
 				InputRate = VertexInputRate.Vertex,
 				Stride = (uint) Marshal.SizeOf<T>()
 			};
@@ -147,25 +146,18 @@ namespace MoonWorks.Graphics
 		public VertexElementFormat Format;
 		public uint Offset;
 
-		public static VertexAttribute Create<T>(
-			string fieldName,
+		public static VertexAttribute Create(
+			uint binding,
 			uint location,
-			uint binding = 0
-		)
-		{
-			var fieldInfo = typeof(T).GetField(fieldName);
-
-			if (fieldInfo == null)
-			{
-				throw new System.ArgumentException("Field not recognized!");
-			}
-
+			VertexElementFormat format,
+			uint offset
+		) {
 			return new VertexAttribute
 			{
-				Binding = binding,
 				Location = location,
-				Format = Conversions.TypeToVertexElementFormat(fieldInfo.FieldType),
-				Offset = (uint) Marshal.OffsetOf<T>(fieldName)
+				Binding = binding,
+				Format = format,
+				Offset = offset
 			};
 		}
 	}

src/Graphics/State/VertexInputState.cs

@@ -10,16 +10,32 @@
 
 		public static readonly VertexInputState Empty = new VertexInputState
 		{
-			VertexBindings = new VertexBinding[0],
-			VertexAttributes = new VertexAttribute[0]
+			VertexBindings = System.Array.Empty<VertexBinding>(),
+			VertexAttributes = System.Array.Empty<VertexAttribute>()
 		};
 
 		public VertexInputState(
 			VertexBinding vertexBinding,
-			params VertexAttribute[] vertexAttributes
+			VertexAttribute[] vertexAttributes
 		) {
 			VertexBindings = new VertexBinding[] { vertexBinding };
 			VertexAttributes = vertexAttributes;
 		}
+
+		public VertexInputState(
+			VertexBinding[] vertexBindings,
+			VertexAttribute[] vertexAttributes
+		) {
+			VertexBindings = vertexBindings;
+			VertexAttributes = vertexAttributes;
+		}
+
+		public static VertexInputState CreateSingleBinding<T>() where T : unmanaged, IVertexType
+		{
+			return new VertexInputState(
+				VertexBinding.Create<T>(),
+				default(T).Attributes()
+			);
+		}
 	}
 }

src/Graphics/Utility/Conversions.cs

@@ -11,39 +11,5 @@
 		{
 			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!"
-				);
-			}
-		}
 	}
 }