some minor cleanups

.circleci/config.yml

@@ -1,46 +0,0 @@
-version: 2.1
-
-defaults: &defaults
-  working_directory: ~/repo
-  docker:
-    - image: mcr.microsoft.com/dotnet/core/sdk:3.0
-      environment:
-        DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1
-        DOTNET_CLI_TELEMETRY_OPTOUT: 1
-
-jobs:
-  test:
-    <<: *defaults
-    steps:
-      - checkout
-      - run: dotnet restore
-      - run: dotnet build -c Release
-      - run: dotnet test -c Release
-      - persist_to_workspace:
-          root: .
-          paths: ./Bonk/bin
-
-  deploy:
-    <<: *defaults
-    steps:
-      - checkout
-      - attach_workspace:
-          at: .
-      - run: dotnet nuget push ./Bonk/bin/Release/MoonTools.Core.Bonk.*.nupkg -k $API_KEY -s https://api.nuget.org/v3/index.json
-
-workflows:
-  version: 2
-  test_and_deploy:
-    jobs:
-      - test:
-          filters:
-            tags:
-              only: /.*/
-      - deploy:
-          requires:
-            - test
-          filters:
-            branches:
-              ignore: /.*/
-            tags:
-              only: /^\d+\.\d+\.\d+(-preview\d*)?$/

.drone.yml

@@ -0,0 +1,24 @@
+kind: pipeline
+type: docker
+name: default
+
+workspace:
+  path: /build
+
+steps:
+- name: test
+  image: mcr.microsoft.com/dotnet/core/sdk:3.1
+  commands:
+    - dotnet build -c Release
+    - dotnet test -c Release
+
+- name: deploy
+  image: mcr.microsoft.com/dotnet/core/sdk:3.1
+  environment:
+    API_KEY:
+      from_secret: API_KEY
+  commands:
+    - dotnet nuget push /build/Bonk/bin/Release/MoonTools.Bonk.*.nupkg -s https://api.nuget.org/v3/index.json -k $API_KEY 
+  when:
+    ref:
+    - refs/tags/*.*.*

Bonk/AABB.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// Axis-aligned bounding box.
@@ -26,11 +26,13 @@ namespace MoonTools.Core.Bonk
 
         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>

Bonk/Bonk.csproj

@@ -1,18 +1,18 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <Version>6.0.0</Version>
+    <Version>8.0.0</Version>
     <TargetFramework>netstandard2.0</TargetFramework>
-    <Description>.NET Core High Performance Collision Detection</Description>
-    <PackageId>MoonTools.Core.Bonk</PackageId>
-    <RootNamespace>MoonTools.Core.Bonk</RootNamespace>
+    <Description>.NET Standard High Performance Collision Detection</Description>
+    <PackageId>MoonTools.Bonk</PackageId>
+    <RootNamespace>MoonTools.Bonk</RootNamespace>
     <Company>Moonside Games</Company>
     <Authors>Evan Hemsley</Authors>
     <Copyright>Evan Hemsley 2019</Copyright>
-    <Product>MoonTools.Core.Bonk</Product>
+    <Product>MoonTools.Bonk</Product>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
-    <AssemblyName>MoonTools.Core.Bonk</AssemblyName>
+    <AssemblyName>MoonTools.Bonk</AssemblyName>
     <PackageLicenseExpression>LGPL-3.0-only</PackageLicenseExpression>
-    <PackageProjectUrl>https://github.com/MoonsideGames/MoonTools.Core.Bonk</PackageProjectUrl>
+    <PackageProjectUrl>https://gitea.moonside.games/MoonsideGames/MoonTools.Bonk</PackageProjectUrl>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
   <ItemGroup>
@@ -20,9 +20,9 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="MoonTools.Core.Structs" Version="3.0.0" />
     <PackageReference Include="System.Collections.Immutable" Version="1.7.0"/>
     <PackageReference Include="System.Numerics.Vectors" Version="4.5.0"/>
     <PackageReference Include="Microsoft.Bcl.HashCode" Version="1.1.0"/>
+    <PackageReference Include="MoonTools.Structs" Version="3.0.1"/>
   </ItemGroup>
 </Project>

Bonk/BroadPhase/SpatialHash.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// Used to quickly check if two shapes are potentially overlapping.
@@ -14,7 +14,13 @@ namespace MoonTools.Core.Bonk
         private readonly int cellSize;
 
         private readonly Dictionary<long, HashSet<T>> hashDictionary = new Dictionary<long, HashSet<T>>();
-        private readonly Dictionary<T, IHasAABB2D> IDLookup = new Dictionary<T, IHasAABB2D>();
+        private readonly Dictionary<T, (IHasAABB2D, Transform2D)> IDLookup = new Dictionary<T, (IHasAABB2D, Transform2D)>();
+
+        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;
+
 
         public SpatialHash(int cellSize)
         {
@@ -31,9 +37,10 @@ namespace MoonTools.Core.Bonk
         /// </summary>
         /// <param name="id">A unique ID for the shape-transform pair.</param>
         /// <param name="shape"></param>
-        public void Insert(T id, IHasAABB2D shape)
+        /// <param name="transform2D"></param>
+        public void Insert(T id, IHasAABB2D shape, Transform2D transform2D)
         {
-            var box = shape.AABB;
+            var box = shape.TransformedAABB(transform2D);
             var minHash = Hash(box.Min);
             var maxHash = Hash(box.Max);
 
@@ -51,30 +58,40 @@ namespace MoonTools.Core.Bonk
                     IDLookup[id] = (shape, transform2D);
                 }
             }
+
+            MinX = Math.Min(MinX, minHash.Item1);
+            MinY = Math.Min(MinY, minHash.Item2);
+            MaxX = Math.Max(MaxX, maxHash.Item1);
+            MaxY = 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, IHasAABB2D)> Retrieve(T id, IHasAABB2D shape)
+        public IEnumerable<(T, IHasAABB2D, Transform2D)> Retrieve(T id, IHasAABB2D shape, Transform2D transform2D)
         {
-            var box = shape.AABB;
-            var minHash = Hash(box.Min);
-            var maxHash = Hash(box.Max);
+            var box = shape.TransformedAABB(transform2D);
+            var (minX, minY) = Hash(box.Min);
+            var (maxX, maxY) = Hash(box.Max);
 
-            for (var i = minHash.Item1; i <= maxHash.Item1; i++)
+            if (minX < MinX) { minX = MinX; }
+            if (maxX > MaxX) { maxX = MaxX; }
+            if (minY < MinY) { minY = MinY; }
+            if (maxY > MaxY) { maxY = MaxY; }
+
+            for (var i = minX; i <= maxX; i++)
             {
-                for (var j = minHash.Item2; j <= maxHash.Item2; j++)
+                for (var j = minY; j <= maxY; j++)
                 {
                     var key = MakeLong(i, j);
                     if (hashDictionary.ContainsKey(key))
                     {
                         foreach (var t in hashDictionary[key])
                         {
-                            var otherShape = IDLookup[t];
-                            if (!id.Equals(t) && AABB.TestOverlap(shape.AABB, otherShape.AABB))
+                            var (otherShape, otherTransform) = IDLookup[t];
+                            if (!id.Equals(t) && AABB.TestOverlap(box, otherShape.TransformedAABB(otherTransform)))
                             {
-                                yield return (t, otherShape);
+                                yield return (t, otherShape, otherTransform);
                             }
                         }
                     }
@@ -82,29 +99,35 @@ namespace MoonTools.Core.Bonk
             }
         }
 
+
         /// <summary>
         /// Retrieves objects based on a pre-transformed AABB.
         /// </summary>
         /// <param name="aabb">A transformed AABB.</param>
         /// <returns></returns>
-        public IEnumerable<(T, IHasAABB2D)> Retrieve(AABB aabb)
+        public IEnumerable<(T, IHasAABB2D, Transform2D)> Retrieve(AABB aabb)
         {
-            var minHash = Hash(aabb.Min);
-            var maxHash = Hash(aabb.Max);
+            var (minX, minY) = Hash(aabb.Min);
+            var (maxX, maxY) = Hash(aabb.Max);
 
-            for (var i = minHash.Item1; i <= maxHash.Item1; i++)
+            if (minX < MinX) { minX = MinX; }
+            if (maxX > MaxX) { maxX = MaxX; }
+            if (minY < MinY) { minY = MinY; }
+            if (maxY > MaxY) { maxY = MaxY; }
+
+            for (var i = minX; i <= maxX; i++)
             {
-                for (var j = minHash.Item2; j <= maxHash.Item2; j++)
+                for (var j = minY; j <= maxY; j++)
                 {
                     var key = MakeLong(i, j);
                     if (hashDictionary.ContainsKey(key))
                     {
                         foreach (var t in hashDictionary[key])
                         {
-                            var otherShape = IDLookup[t];
-                            if (AABB.TestOverlap(aabb, otherShape.AABB))
+                            var (otherShape, otherTransform) = IDLookup[t];
+                            if (AABB.TestOverlap(aabb, otherShape.TransformedAABB(otherTransform)))
                             {
-                                yield return (t, otherShape);
+                                yield return (t, otherShape, otherTransform);
                             }
                         }
                     }

Bonk/ICollisionTestable.cs

@@ -1,15 +0,0 @@
-using System.Collections.Generic;
-
-namespace MoonTools.Core.Bonk
-{
-    public interface ICollisionTestable
-    {
-        bool TestCollision<T>(ICollisionTestable collisionTestable) where T : struct, IShape2D;
-        IEnumerable<TransformedShape2D<T>> TransformedShapes<T>() where T : struct, IShape2D;
-    }
-
-    public interface ICollisionTestable<T> : ICollisionTestable where T : struct, IShape2D
-    {
-        IEnumerable<TransformedShape2D<T>> TransformedShapes { get; }
-    }
-}

Bonk/IHasAABB2D.cs

@@ -1,7 +1,16 @@
-namespace MoonTools.Core.Bonk
+using MoonTools.Structs;
+
+namespace MoonTools.Bonk
 {
     public interface IHasAABB2D
     {
         AABB AABB { get; }
+
+        /// <summary>
+        /// Returns a bounding box based on the shape.
+        /// </summary>
+        /// <param name="transform">A Transform for transforming the shape vertices.</param>
+        /// <returns>Returns a bounding box based on the shape.</returns>
+        AABB TransformedAABB(Transform2D transform);
     }
 }

Bonk/IShape2D.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     public interface IShape2D : IHasAABB2D, IEquatable<IShape2D>
     {
@@ -13,7 +13,5 @@ namespace MoonTools.Core.Bonk
         /// <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);
-
-        AABB TransformedAABB(Transform2D transform);
     }
 }

Bonk/MinkowskiDifference.cs

@@ -1,50 +1,57 @@
 using System;
 using System.Numerics;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// A Minkowski difference between two shapes.
     /// </summary>
-    public struct MinkowskiDifference<T, U> : IEquatable<MinkowskiDifference<T, U>> where T : struct, IShape2D where U : struct, IShape2D
+    public struct MinkowskiDifference : IEquatable<MinkowskiDifference>
     {
-        private TransformedShape2D<T> ShapeA { get; }
-        private TransformedShape2D<U> ShapeB { get; }
+        private IShape2D ShapeA { get; }
+        private Transform2D TransformA { get; }
+        private IShape2D ShapeB { get; }
+        private Transform2D TransformB { get; }
 
-        public MinkowskiDifference(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB)
+        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) - ShapeB.Support(-direction);
+            return ShapeA.Support(direction, TransformA) - ShapeB.Support(-direction, TransformB);
         }
 
         public override bool Equals(object other)
         {
-            return other is MinkowskiDifference<T, U> minkowskiDifference && Equals(minkowskiDifference);
+            return other is MinkowskiDifference minkowskiDifference && Equals(minkowskiDifference);
         }
 
-        public bool Equals(MinkowskiDifference<T, U> other)
+        public bool Equals(MinkowskiDifference other)
         {
             return
                 ShapeA == other.ShapeA &&
-                ShapeB == other.ShapeB;
+                TransformA == other.TransformA &&
+                ShapeB == other.ShapeB &&
+                TransformB == other.TransformB;
         }
 
         public override int GetHashCode()
         {
-            return HashCode.Combine(ShapeA, ShapeB);
+            return HashCode.Combine(ShapeA, TransformA, ShapeB, TransformB);
         }
 
-        public static bool operator ==(MinkowskiDifference<T, U> a, MinkowskiDifference<T, U> b)
+        public static bool operator ==(MinkowskiDifference a, MinkowskiDifference b)
         {
             return a.Equals(b);
         }
 
-        public static bool operator !=(MinkowskiDifference<T, U> a, MinkowskiDifference<T, U> b)
+        public static bool operator !=(MinkowskiDifference a, MinkowskiDifference b)
         {
             return !(a == b);
         }

Bonk/MultiShape.cs

@@ -1,33 +1,21 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
-using MoonTools.Core.Structs;
+using System.Numerics;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
-    public struct MultiShape<TShape2D> : IHasAABB2D, ICollisionTestable<TShape2D> where TShape2D : struct, IShape2D
+    public struct MultiShape : IHasAABB2D
     {
-        private static ImmutableArray<TransformedShape2D<TShape2D>>.Builder _builder = ImmutableArray.CreateBuilder<TransformedShape2D<TShape2D>>();
-        private ImmutableArray<TransformedShape2D<TShape2D>> _transformedShapes;
-        public IEnumerable<TransformedShape2D<TShape2D>> TransformedShapes { get { return _transformedShapes; } }
+        public ImmutableArray<(IShape2D, Transform2D)> ShapeTransformPairs { get; }
 
         public AABB AABB { get; }
 
-        public MultiShape(ImmutableArray<(TShape2D, Transform2D)> shapeTransformPairs)
+        public MultiShape(ImmutableArray<(IShape2D, Transform2D)> shapeTransformPairs)
         {
-            _builder.Clear();
-            foreach (var (shape, transform) in shapeTransformPairs)
-            {
-                _builder.Add(new TransformedShape2D<TShape2D>(shape, transform));
-            }
+            ShapeTransformPairs = shapeTransformPairs;
 
-            _transformedShapes = _builder.ToImmutable();
-            AABB = AABBFromShapes(_transformedShapes);
-        }
-
-        public MultiShape(ImmutableArray<TransformedShape2D<TShape2D>> transformedShapes)
-        {
-            _transformedShapes = transformedShapes;
-            AABB = AABBFromShapes(transformedShapes);
+            AABB = AABBFromShapes(shapeTransformPairs);
         }
 
         public AABB TransformedAABB(Transform2D transform)
@@ -35,24 +23,40 @@ namespace MoonTools.Core.Bonk
             return AABB.Transformed(AABB, transform);
         }
 
-        public IEnumerable<TransformedShape2D<TShape2D>> Compose(Transform2D transform)
+        /// <summary>
+        /// Moves the shapes by pivoting with an offset transform. 
+        /// </summary>
+        /// <param name="offsetTransform"></param>
+        /// <returns></returns>
+        public IEnumerable<(IShape2D, Transform2D)> TransformShapesUsingOffset(Transform2D offsetTransform)
         {
-            foreach (var transformedShape in TransformedShapes)
+            foreach (var (shape, shapeTransform) in ShapeTransformPairs)
             {
-                yield return transformedShape.Compose(transform);
+                var newTransform = new Transform2D(Vector2.Transform(shapeTransform.Position, offsetTransform.TransformMatrix), offsetTransform.Rotation, offsetTransform.Scale);
+                yield return (shape, newTransform);
             }
         }
 
-        private static AABB AABBFromShapes(IEnumerable<TransformedShape2D<TShape2D>> transformedShapes)
+        public bool IsSingleShape<T>() where T : struct, IShape2D
+        {
+            return ShapeTransformPairs.Length == 1 && ShapeTransformPairs[0].Item1 is T;
+        }
+
+        public (T, Transform2D) ShapeTransformPair<T>() where T : struct, IShape2D
+        {
+            return ((T, Transform2D))ShapeTransformPairs[0];
+        }
+
+        private static AABB AABBFromShapes(IEnumerable<(IShape2D, Transform2D)> shapeTransforms)
         {
             var minX = float.MaxValue;
             var minY = float.MaxValue;
             var maxX = float.MinValue;
             var maxY = float.MinValue;
 
-            foreach (var transformedShape in transformedShapes)
+            foreach (var (shape, transform) in shapeTransforms)
             {
-                var aabb = transformedShape.AABB;
+                var aabb = shape.TransformedAABB(transform);
 
                 if (aabb.Min.X < minX)
                 {

Bonk/NarrowPhase/Edge.cs

@@ -1,6 +1,6 @@
 using System.Numerics;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     internal struct Edge
     {

Bonk/NarrowPhase/NarrowPhase.cs

@@ -1,9 +1,7 @@
-using MoonTools.Core.Structs;
-using System;
-using System.Collections.Generic;
+using MoonTools.Structs;
 using System.Numerics;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     public static class NarrowPhase
     {
@@ -13,37 +11,52 @@ namespace MoonTools.Core.Bonk
             CounterClockwise
         }
 
-        public static bool TestCollision<T, U>(ICollisionTestable<T> a, ICollisionTestable<U> b) where T : struct, IShape2D where U : struct, IShape2D
+        /// <summary>
+        /// Tests if two shape-transform pairs are overlapping. Automatically detects fast-path optimizations.
+        /// </summary>
+        public static bool TestCollision(IHasAABB2D hasBoundingBoxA, Transform2D transformA, IHasAABB2D hasBoundingBoxB, Transform2D transformB)
         {
-            foreach (var shape in a.TransformedShapes)
+            if (hasBoundingBoxA is MultiShape && hasBoundingBoxB is MultiShape)
             {
-                foreach (var shapeB in b.TransformedShapes)
-                {
-                    return TestCollision(shape, shapeB);
+                return TestCollision((MultiShape)hasBoundingBoxA, transformA, (MultiShape)hasBoundingBoxB, transformB);
             }
+            else if (hasBoundingBoxA is MultiShape && hasBoundingBoxB is IShape2D)
+            {
+                return TestCollision((MultiShape)hasBoundingBoxA, transformA, (IShape2D)hasBoundingBoxB, transformB);
+            }
+            else if (hasBoundingBoxA is IShape2D && hasBoundingBoxB is MultiShape)
+            {
+                return TestCollision((IShape2D)hasBoundingBoxA, transformA, (MultiShape)hasBoundingBoxB, transformB);
+            }
+            else if (hasBoundingBoxA is IShape2D && hasBoundingBoxB is IShape2D)
+            {
+                return TestCollision((IShape2D)hasBoundingBoxA, transformA, (IShape2D)hasBoundingBoxB, transformB);
+            }
+            else
+            {
+                throw new System.ArgumentException("Collision testing requires MultiShapes or IShape2Ds.");
             }
-            return false;
         }
 
-        /// <summary>
-        /// Tests if two shape-transform pairs are overlapping.
-        /// </summary>
-        public static bool TestCollision<T, U>(T shape, Transform2D transform, U shapeB, Transform2D transformB) where T : struct, IShape2D where U : struct, IShape2D
+        public static bool TestCollision(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
         {
-            return TestCollision(new TransformedShape2D<T>(shape, transform), new TransformedShape2D<U>(shapeB, transformB));
+            if (shapeA is Rectangle rectangleA && shapeB is Rectangle rectangleB && transformA.Rotation == 0 && transformB.Rotation == 0)
+            {
+                return TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB);
             }
-
-        /// <summary>
-        /// Tests if two TransformedShapes are overlapping.
-        /// </summary>
-        /// <typeparam name="T"></typeparam>
-        /// <typeparam name="U"></typeparam>
-        /// <param name="transformedShapeA"></param>
-        /// <param name="transformedShapeB"></param>
-        /// <returns></returns>
-        public static bool TestCollision<T, U>(TransformedShape2D<T> transformedShapeA, TransformedShape2D<U> transformedShapeB) where T : struct, IShape2D where U : struct, IShape2D
+            else if (shapeA is Point && shapeB is Rectangle && transformB.Rotation == 0)
             {
-            return FindCollisionSimplex(transformedShapeA, transformedShapeB).Item1;
+                return TestPointRectangleOverlap((Point)shapeA, transformA, (Rectangle)shapeB, transformB);
+            }
+            else if (shapeA is Rectangle && shapeB is Point && transformA.Rotation == 0)
+            {
+                return TestPointRectangleOverlap((Point)shapeB, transformB, (Rectangle)shapeA, transformA);
+            }
+            else if (shapeA is Circle circleA && shapeB is Circle circleB && transformA.Scale.X == transformA.Scale.Y && transformB.Scale.X == transformB.Scale.Y)
+            {
+                return TestCircleOverlap(circleA, transformA, circleB, transformB);
+            }
+            return FindCollisionSimplex(shapeA, transformA, shapeB, transformB).Item1;
         }
 
         /// <summary>
@@ -53,21 +66,13 @@ namespace MoonTools.Core.Bonk
         /// <param name="multiShape"></param>
         /// <param name="multiShapeTransform"></param>
         /// <param name="shape"></param>
+        /// <param name="shapeTransform"></param>
         /// <returns></returns>
-        public static bool TestCollision<T, U>(MultiShape<T> multiShape, Transform2D multiShapeTransform, TransformedShape2D<U> shape) where T : struct, IShape2D where U : struct, IShape2D
+        public static bool TestCollision(MultiShape multiShape, Transform2D multiShapeTransform, IShape2D shape, Transform2D shapeTransform)
         {
-            foreach (var transformedShape in multiShape.Compose(multiShapeTransform))
+            foreach (var (otherShape, otherTransform) in multiShape.TransformShapesUsingOffset(multiShapeTransform))
             {
-                if (TestCollision(shape, transformedShape)) { return true; }
-            }
-            return false;
-        }
-
-        public static bool TestCollison<T>(IEnumerable<TransformedShape2D<T>> transformedShapes, Transform2D multiShapeTransform, TransformedShape2D<U> shape) where T : struct, IShape2D where U : struct, IShape2D
-        {
-            foreach (var transformedShape in transformedShapes)
-            {
-                if (TestCollision(transformedShape.Compose(multiShapeTransform), shape)) { return true; }
+                if (TestCollision(shape, shapeTransform, otherShape, otherTransform)) { return true; }
             }
             return false;
         }
@@ -79,10 +84,15 @@ namespace MoonTools.Core.Bonk
         /// <param name="multiShape"></param>
         /// <param name="multiShapeTransform"></param>
         /// <param name="shape"></param>
+        /// <param name="shapeTransform"></param>
         /// <returns></returns>
-        public static bool TestCollision<T, U>(TransformedShape2D<T> shape, MultiShape<U> multiShape, Transform2D multiShapeTransform) where T : struct, IShape2D where U : struct, IShape2D
+        public static bool TestCollision(IShape2D shape, Transform2D shapeTransform, MultiShape multiShape, Transform2D multiShapeTransform)
         {
-            return TestCollision(multiShape, multiShapeTransform, shape);
+            foreach (var (otherShape, otherTransform) in multiShape.TransformShapesUsingOffset(multiShapeTransform))
+            {
+                if (TestCollision(shape, shapeTransform, otherShape, otherTransform)) { return true; }
+            }
+            return false;
         }
 
         /// <summary>
@@ -94,13 +104,13 @@ namespace MoonTools.Core.Bonk
         /// <param name="multiShapeB"></param>
         /// <param name="transformB"></param>
         /// <returns></returns>
-        public static bool TestCollision<T, U>(MultiShape<T> multiShapeA, Transform2D transformA, MultiShape<U> multiShapeB, Transform2D transformB) where T : struct, IShape2D where U : struct, IShape2D
+        public static bool TestCollision(MultiShape multiShapeA, Transform2D transformA, MultiShape multiShapeB, Transform2D transformB)
         {
-            foreach (var transformedShapeA in multiShapeA.Compose(transformA))
+            foreach (var (shapeA, shapeTransformA) in multiShapeA.TransformShapesUsingOffset(transformA))
             {
-                foreach (var transformedShapeB in multiShapeB.Compose(transformB))
+                foreach (var (shapeB, shapeTransformB) in multiShapeB.TransformShapesUsingOffset(transformB))
                 {
-                    if (TestCollision(transformedShapeA, transformedShapeB)) { return true; }
+                    if (TestCollision(shapeA, shapeTransformA, shapeB, shapeTransformB)) { return true; }
                 }
             }
             return false;
@@ -110,12 +120,14 @@ namespace MoonTools.Core.Bonk
         /// Fast path for axis-aligned rectangles. If the transforms have non-zero rotation this will be inaccurate.
         /// </summary>
         /// <param name="rectangleA"></param>
+        /// <param name="transformA"></param>
         /// <param name="rectangleB"></param>
+        /// <param name="transformB"></param>
         /// <returns></returns>
-        public static bool TestCollision(TransformedShape2D<Rectangle> rectangleA, TransformedShape2D<Rectangle> rectangleB)
+        public static bool TestRectangleOverlap(Rectangle rectangleA, Transform2D transformA, Rectangle rectangleB, Transform2D transformB)
         {
-            var firstAABB = rectangleA.AABB;
-            var secondAABB = rectangleB.AABB;
+            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;
         }
@@ -124,34 +136,33 @@ namespace MoonTools.Core.Bonk
         /// Fast path for overlapping point and axis-aligned rectangle. The rectangle transform must have non-zero rotation.
         /// </summary>
         /// <param name="point"></param>
+        /// <param name="pointTransform"></param>
         /// <param name="rectangle"></param>
+        /// <param name="rectangleTransform"></param>
         /// <returns></returns>
-        public static bool TestCollision(TransformedShape2D<Point> point, TransformedShape2D<Rectangle> rectangle)
+        public static bool TestPointRectangleOverlap(Point point, Transform2D pointTransform, Rectangle rectangle, Transform2D rectangleTransform)
         {
-            var transformedPoint = point.Transform.Position;
-            var AABB = rectangle.AABB;
+            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 TestCollision(TransformedShape2D<Rectangle> rectangle, TransformedShape2D<Point> point)
-        {
-            return TestCollision(point, rectangle);
-        }
-
         /// <summary>
         /// Fast path for overlapping circles. The circles must have uniform scaling.
         /// </summary>
         /// <param name="circleA"></param>
+        /// <param name="transformA"></param>
         /// <param name="circleB"></param>
+        /// <param name="transformB"></param>
         /// <returns></returns>
-        public static bool TestCollision(TransformedShape2D<Circle> circleA, TransformedShape2D<Circle> circleB)
+        public static bool TestCircleOverlap(Circle circleA, Transform2D transformA, Circle circleB, Transform2D transformB)
         {
-            var radiusA = circleA.Shape.Radius * circleA.Transform.Scale.X;
-            var radiusB = circleB.Shape.Radius * circleB.Transform.Scale.Y;
+            var radiusA = circleA.Radius * transformA.Scale.X;
+            var radiusB = circleB.Radius * transformB.Scale.Y;
 
-            var centerA = circleA.Transform.Position;
-            var centerB = circleB.Transform.Position;
+            var centerA = transformA.Position;
+            var centerB = transformB.Position;
 
             var distanceSquared = (centerA - centerB).LengthSquared();
             var radiusSumSquared = (radiusA + radiusB) * (radiusA + radiusB);
@@ -162,9 +173,9 @@ namespace MoonTools.Core.Bonk
         /// <summary>
         /// Tests if the two shape-transform pairs are overlapping, and returns a simplex that can be used by the EPA algorithm to determine a miminum separating vector.
         /// </summary>
-        public static (bool, Simplex2D) FindCollisionSimplex<T, U>(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB) where T : struct, IShape2D where U : struct, IShape2D
+        public static (bool, Simplex2D) FindCollisionSimplex(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB)
         {
-            var minkowskiDifference = new MinkowskiDifference<T, U>(shapeA, shapeB);
+            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);
@@ -174,7 +185,7 @@ namespace MoonTools.Core.Bonk
         /// Returns a minimum separating vector in the direction from A to B.
         /// </summary>
         /// <param name="simplex">A simplex returned by the GJK algorithm.</param>
-        public unsafe static Vector2 Intersect<T, U>(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB, Simplex2D simplex) where T : struct, IShape2D where U : struct, IShape2D
+        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)); }
@@ -196,7 +207,7 @@ namespace MoonTools.Core.Bonk
             for (var i = 0; i < 32; i++)
             {
                 var edge = FindClosestEdge(winding, simplexVertices);
-                var support = CalculateSupport(shapeA, shapeB, edge.normal);
+                var support = CalculateSupport(shapeA, Transform2DA, shapeB, Transform2DB, edge.normal);
                 var distance = Vector2.Dot(support, edge.normal);
 
                 intersection = edge.normal;
@@ -250,12 +261,12 @@ namespace MoonTools.Core.Bonk
             return new Edge(closestDistance, closestNormal, closestIndex);
         }
 
-        private static Vector2 CalculateSupport<T, U>(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB, Vector2 direction) where T : struct, IShape2D where U : struct, IShape2D
+        private static Vector2 CalculateSupport(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Vector2 direction)
         {
-            return shapeA.Support(direction) - shapeB.Support(-direction);
+            return shapeA.Support(direction, Transform2DA) - shapeB.Support(-direction, Transform2DB);
         }
 
-        private static (bool, Simplex2D) Check<T, U>(MinkowskiDifference<T, U> minkowskiDifference, Vector2 c, Vector2 b) where T : struct, IShape2D where U : struct, IShape2D
+        private static (bool, Simplex2D) Check(MinkowskiDifference minkowskiDifference, Vector2 c, Vector2 b)
         {
             var cb = c - b;
             var c0 = -c;
@@ -263,7 +274,7 @@ namespace MoonTools.Core.Bonk
             return DoSimplex(minkowskiDifference, new Simplex2D(b, c), d);
         }
 
-        private static (bool, Simplex2D) DoSimplex<T, U>(MinkowskiDifference<T, U> minkowskiDifference, Simplex2D simplex, Vector2 direction) where T : struct, IShape2D where U : struct, IShape2D
+        private static (bool, Simplex2D) DoSimplex(MinkowskiDifference minkowskiDifference, Simplex2D simplex, Vector2 direction)
         {
             var a = minkowskiDifference.Support(direction);
             var notPastOrigin = Vector2.Dot(a, direction) < 0;

Bonk/NarrowPhase/SimplexVertexBuffer.cs

@@ -1,8 +1,8 @@
 using System.Collections.Generic;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     internal unsafe struct SimplexVertexBuffer
     {

Bonk/Shapes/Circle.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// A Circle is a shape defined by a radius.

Bonk/Shapes/Line.cs

@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// A line is a shape defined by exactly two points in space.

Bonk/Shapes/Point.cs

@@ -1,9 +1,12 @@
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
+    /// <summary>
+    /// A Point is "that which has not part". All points by themselves are identical.
+    /// </summary>
     public struct Point : IShape2D, IEquatable<Point>
     {
         public AABB AABB { get; }

Bonk/Shapes/Polygon.cs

@@ -2,9 +2,9 @@
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// A Shape defined by an arbitrary collection of vertices.
@@ -59,7 +59,7 @@ namespace MoonTools.Core.Bonk
 
         public bool Equals(IShape2D other)
         {
-            return (other is Polygon otherPolygon && Equals(otherPolygon));
+            return other is Polygon otherPolygon && Equals(otherPolygon);
         }
 
         public bool Equals(Polygon other)

Bonk/Shapes/Rectangle.cs

@@ -1,8 +1,8 @@
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// A rectangle is a shape defined by a width and height. The origin is the center of the rectangle.
@@ -23,15 +23,15 @@ namespace MoonTools.Core.Bonk
         public Vector2 Min { get; }
         public Vector2 Max { get; }
 
-        public Rectangle(int width, int height)
+        public Rectangle(int left, int top, int width, int height)
         {
             Width = width;
             Height = height;
-            AABB = new AABB(-width / 2f, -height / 2f, width / 2f, height / 2f);
-            Right = AABB.Right;
-            Left = AABB.Left;
-            Top = AABB.Top;
-            Bottom = AABB.Bottom;
+            Left = left;
+            Right = left + width;
+            Top = top;
+            Bottom = top + height;
+            AABB = new AABB(left, top, Right, Bottom);
             BottomLeft = new Vector2(Left, Bottom);
             TopRight = new Vector2(Top, Right);
             Min = AABB.Min;

Bonk/Simplex.cs

@@ -1,9 +1,9 @@
 using System.Collections.Generic;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 using System;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     /// <summary>
     /// A simplex is a shape with up to n - 2 vertices in the nth dimension.

Bonk/SweepTest/SweepResult.cs

@@ -1,26 +1,21 @@
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
-    public struct SweepResult<T, U> where T : IEquatable<T> where U : struct, IShape2D
+    public struct SweepResult<T> where T : IEquatable<T>
     {
-        public static SweepResult<T, U> False = new SweepResult<T, U>();
+        public readonly static SweepResult<T> False = new SweepResult<T>();
 
         public bool Hit { get; }
         public Vector2 Motion { get; }
         public T ID { get; }
-        public U Shape { get; }
-        public Transform2D Transform { get; }
 
-        public SweepResult(bool hit, Vector2 motion, T id, U shape, Transform2D transform)
+        public SweepResult(bool hit, Vector2 motion, T id)
         {
             Hit = hit;
             Motion = motion;
             ID = id;
-            Shape = shape;
-            Transform = transform;
         }
     }
 }

Bonk/SweepTest/SweepTest.cs

@@ -1,13 +1,13 @@
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
+using MoonTools.Structs;
 
-namespace MoonTools.Core.Bonk
+namespace MoonTools.Bonk
 {
     public static class SweepTest
     {
         /// <summary>
-        /// Performs a sweep test on rectangles.
+        /// Performs a sweep test on and against rectangles. Returns the position 1 pixel before overlap occurs.
         /// </summary>
         /// <typeparam name="T"></typeparam>
         /// <param name="spatialHash">A spatial hash.</param>
@@ -15,7 +15,7 @@ namespace MoonTools.Core.Bonk
         /// <param name="transform">A transform by which to transform the IHasAABB2D.</param>
         /// <param name="ray">Given in world-space.</param>
         /// <returns></returns>
-        public static SweepResult<T, Rectangle> Rectangle<T>(SpatialHash<T> spatialHash, Rectangle rectangle, Transform2D transform, Vector2 ray) where T : IEquatable<T>
+        public static SweepResult<T> Test<T>(SpatialHash<T> spatialHash, Rectangle rectangle, Transform2D transform, Vector2 ray) where T : IEquatable<T>
         {
             var transformedAABB = rectangle.TransformedAABB(transform);
             var sweepBox = SweepBox(transformedAABB, ray);
@@ -27,27 +27,45 @@ namespace MoonTools.Core.Bonk
 
             foreach (var (id, shape, shapeTransform) in spatialHash.Retrieve(sweepBox))
             {
-                if (shape is Rectangle otherRectangle)
+                Rectangle otherRectangle;
+                Transform2D otherTransform;
+                AABB otherTransformedAABB;
+                if (shape is Rectangle)
                 {
-                    var otherTransformedAABB = otherRectangle.TransformedAABB(shapeTransform);
+                    otherRectangle = (Rectangle)shape;
+                    otherTransformedAABB = shape.TransformedAABB(shapeTransform);
+                    otherTransform = shapeTransform;
+                }
+                else if (shape is MultiShape multiShape && multiShape.IsSingleShape<Rectangle>())
+                {
+                    Transform2D rectangleOffset;
+                    (otherRectangle, rectangleOffset) = multiShape.ShapeTransformPair<Rectangle>();
+                    otherTransform = shapeTransform.Compose(rectangleOffset);
+                    otherTransformedAABB = shape.TransformedAABB(otherTransform);
+                }
+                else
+                {
+                    continue;
+                }
+
                 float xInvEntry, yInvEntry;
 
                 if (ray.X > 0)
                 {
-                        xInvEntry = shapeTransform.Position.X - (transform.Position.X + transformedAABB.Width);
+                    xInvEntry = otherTransformedAABB.Left - (transformedAABB.Right);
                 }
                 else
                 {
-                        xInvEntry = (shapeTransform.Position.X + otherTransformedAABB.Width) - transform.Position.X;
+                    xInvEntry = (otherTransformedAABB.Right) - transformedAABB.Left;
                 }
 
                 if (ray.Y > 0)
                 {
-                        yInvEntry = shapeTransform.Position.Y - (transform.Position.Y + transformedAABB.Height);
+                    yInvEntry = otherTransformedAABB.Top - (transformedAABB.Bottom);
                 }
                 else
                 {
-                        yInvEntry = (shapeTransform.Position.Y + otherTransformedAABB.Height) - shapeTransform.Position.Y;
+                    yInvEntry = (otherTransformedAABB.Bottom) - transformedAABB.Top;
                 }
 
                 float xEntry, yEntry;
@@ -72,29 +90,37 @@ namespace MoonTools.Core.Bonk
 
                 var entryTime = Math.Max(xEntry, yEntry);
 
-                    if (entryTime > 0 && entryTime < 1)
+                if (entryTime >= 0 && entryTime <= 1)
                 {
                     if (entryTime < shortestDistance)
                     {
                         shortestDistance = entryTime;
                         nearestID = id;
-                            nearestRectangle = rectangle;
+                        nearestRectangle = otherRectangle;
                         nearestTransform = shapeTransform;
                     }
                 }
-                }
+
             }
 
             if (nearestRectangle.HasValue)
             {
-                return new SweepResult<T, Rectangle>(true, ray * shortestDistance, nearestID, nearestRectangle.Value, nearestTransform.Value);
+                var overlapPosition = ray * shortestDistance;
+                var correctionX = -Math.Sign(ray.X);
+                var correctionY = -Math.Sign(ray.Y);
+                return new SweepResult<T>(true, new Position2D((int)overlapPosition.X + correctionX, (int)overlapPosition.Y + correctionY), nearestID);
             }
             else
             {
-                return SweepResult<T, Rectangle>.False;
+                return SweepResult<T>.False;
             }
         }
 
+        public static SweepResult<T> Test<T>(SpatialHash<T> spatialHash, Point point, Transform2D transform, Vector2 ray) where T : IEquatable<T>
+        {
+            return Test(spatialHash, new Rectangle(0, 0, 0, 0), transform, ray);
+        }
+
         private static AABB SweepBox(AABB aabb, Vector2 ray)
         {
             return new AABB(

Bonk/TransformedShape2D.cs

@@ -1,78 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Numerics;
-using MoonTools.Core.Structs;
-
-namespace MoonTools.Core.Bonk
-{
-    public struct TransformedShape2D<TShape2D> : IEquatable<TransformedShape2D<TShape2D>>, ICollisionTestable<TShape2D>, IHasAABB2D where TShape2D : struct, IShape2D
-    {
-        public TShape2D Shape { get; }
-        public Transform2D Transform { get; }
-        public AABB AABB { get; }
-        public IEnumerable<TransformedShape2D<TShape2D>> TransformedShapes { get { yield return this; } }
-
-        public TransformedShape2D(TShape2D shape, Transform2D transform)
-        {
-            Shape = shape;
-            Transform = transform;
-            AABB = shape.TransformedAABB(transform);
-        }
-
-        public TransformedShape2D<TShape2D> Compose(Transform2D transform)
-        {
-            return new TransformedShape2D<TShape2D>(Shape, Transform.Compose(transform));
-        }
-
-        public Vector2 Support(Vector2 direction)
-        {
-            return Shape.Support(direction, Transform);
-        }
-
-        public void Deconstruct(out TShape2D shape, out Transform2D transform)
-        {
-            shape = Shape;
-            transform = Transform;
-        }
-
-        public bool TestCollision<U>(ICollisionTestable collisionTestable) where U : struct, IShape2D
-        {
-            return NarrowPhase.TestCollision(TransformedShapes, collisionTestable.TransformedShapes);
-            if (collisionTestable is MultiShape<U> multiShape)
-            {
-                return NarrowPhase.TestCollision(this, multiShape);
-            }
-            else if (collisionTestable is TransformedShape2D<U> shape)
-            {
-                return NarrowPhase.TestCollision(this, shape);
-            }
-            return false;
-        }
-
-        public override bool Equals(object obj)
-        {
-            return obj is TransformedShape2D<TShape2D> d && Equals(d);
-        }
-
-        public bool Equals(TransformedShape2D<TShape2D> other)
-        {
-            return Shape.Equals(other.Shape) &&
-                   Transform.Equals(other.Transform);
-        }
-
-        public override int GetHashCode()
-        {
-            return HashCode.Combine(Shape, Transform);
-        }
-
-        public static bool operator ==(TransformedShape2D<TShape2D> left, TransformedShape2D<TShape2D> right)
-        {
-            return left.Equals(right);
-        }
-
-        public static bool operator !=(TransformedShape2D<TShape2D> left, TransformedShape2D<TShape2D> right)
-        {
-            return !(left == right);
-        }
-    }
-}

Bonk/Vector2Extensions.cs

@@ -1,6 +1,6 @@
 using System.Numerics;
 
-namespace MoonTools.Core.Bonk.Extensions
+namespace MoonTools.Bonk.Extensions
 {
     internal static class Vector2Extensions
     {

README.md

@@ -1,7 +1,7 @@
-# MoonTools.Core.Bonk
+# MoonTools.Bonk
 
-[![NuGet Badge](https://buildstats.info/nuget/MoonTools.Core.Bonk)](https://www.nuget.org/packages/MoonTools.Core.Bonk/)
-[![CircleCI](https://circleci.com/gh/MoonsideGames/MoonTools.Core.Bonk.svg?style=svg)](https://circleci.com/gh/MoonsideGames/MoonTools.Core.Bonk)
+[![NuGet Badge](https://buildstats.info/nuget/MoonTools.Bonk)](https://www.nuget.org/packages/MoonTools.Bonk/)
+[![Build Status](https://drone.moonside.games/api/badges/MoonsideGames/MoonTools.Bonk/status.svg)](https://drone.moonside.games/MoonsideGames/MoonTools.Bonk)
 
 Bonk is a fast and modular collision detection system for .NET that is part of the MoonTools suite. It can be used with any .NET-based game engine.
 

Test/AABBTest.cs

@@ -1,6 +1,6 @@
 using NUnit.Framework;
 using FluentAssertions;
-using MoonTools.Core.Bonk;
+using MoonTools.Bonk;
 using System.Numerics;
 
 namespace Tests

Test/EPA2DTest.cs

@@ -3,8 +3,8 @@ using FluentAssertions;
 
 using System;
 using System.Numerics;
-using MoonTools.Core.Structs;
-using MoonTools.Core.Bonk;
+using MoonTools.Structs;
+using MoonTools.Bonk;
 
 namespace Tests
 {
@@ -13,61 +13,70 @@ namespace Tests
         [Test]
         public void RectangleOverlap()
         {
-            var squareA = new TransformedShape2D<Rectangle>(new Rectangle(2, 2), Transform2D.DefaultTransform);
-            var squareB = new TransformedShape2D<Rectangle>(new Rectangle(2, 2), new Transform2D(new Vector2(1.5f, 0)));
+            var squareA = new Rectangle(-1, -1, 2, 2);
+            var transformA = Transform2D.DefaultTransform;
+            var squareB = new Rectangle(-1, -1, 2, 2);
+            var transformB = new Transform2D(new Vector2(1.5f, 0));
 
-            var (result, simplex) = NarrowPhase.FindCollisionSimplex(squareA, squareB);
+            var (result, simplex) = NarrowPhase.FindCollisionSimplex(squareA, transformA, squareB, transformB);
 
             result.Should().BeTrue();
 
-            var intersection = NarrowPhase.Intersect(squareA, squareB, simplex);
+            var intersection = NarrowPhase.Intersect(squareA, transformA, squareB, transformB, simplex);
 
             intersection.X.Should().Be(1f);
             intersection.Y.Should().Be(0);
 
-            var movedTransform = new Transform2D(-(intersection * 1.01f)); // move a tiny bit past
+            var movedTransform = new Transform2D(transformA.Position - (intersection * 2)); // move past
 
-            NarrowPhase.TestCollision(squareA.Compose(movedTransform), squareB).Should().BeFalse();
+            NarrowPhase.TestCollision(squareA, movedTransform, squareB, transformB).Should().BeFalse();
         }
 
         [Test]
         public void CircleOverlap()
         {
-            var circleA = new TransformedShape2D<Circle>(new Circle(2), Transform2D.DefaultTransform);
-            var circleB = new TransformedShape2D<Circle>(new Circle(1), new Transform2D(new Vector2(1, 1)));
+            var circleA = new Circle(2);
+            var transformA = Transform2D.DefaultTransform;
+            var circleB = new Circle(1);
+            var transformB = new Transform2D(new Vector2(1, 1));
 
-            var (result, simplex) = NarrowPhase.FindCollisionSimplex(circleA, circleB);
+            var (result, simplex) = NarrowPhase.FindCollisionSimplex(circleA, transformA, circleB, transformB);
 
             result.Should().BeTrue();
 
-            var intersection = NarrowPhase.Intersect(circleA, circleB, simplex);
+            var intersection = NarrowPhase.Intersect(circleA, transformA, circleB, transformB, simplex);
 
-            var ix = (2 * (float)Math.Cos(Math.PI / 4)) - ((1 * (float)Math.Cos(5 * Math.PI / 4)) + 1);
-            var iy = (2 * (float)Math.Sin(Math.PI / 4)) - ((1 * (float)Math.Sin(5 * Math.PI / 4)) + 1);
+            var ix = (circleA.Radius * (float)Math.Cos(Math.PI / 4)) - ((circleB.Radius * (float)Math.Cos(5 * Math.PI / 4)) + transformB.Position.X);
+            var iy = (circleA.Radius * (float)Math.Sin(Math.PI / 4)) - ((circleB.Radius * (float)Math.Sin(5 * Math.PI / 4)) + transformB.Position.Y);
 
             intersection.X.Should().BeApproximately(ix, 0.01f);
             intersection.Y.Should().BeApproximately(iy, 0.01f);
 
-            var movedTransform = new Transform2D(-(intersection * 1.01f)); // move a tiny bit past
+            var movedTransform = new Transform2D(transformA.Position - (intersection * 2)); // move past
 
-            NarrowPhase.TestCollision(circleA.Compose(movedTransform), circleB).Should().BeFalse();
+            NarrowPhase.TestCollision(circleA, movedTransform, circleB, transformB).Should().BeFalse();
         }
 
         [Test]
         public void LineRectangleOverlap()
         {
-            var line = new TransformedShape2D<Line>(new Line(new Position2D(-4, -4), new Position2D(4, 4)), Transform2D.DefaultTransform);
-            var square = new TransformedShape2D<Rectangle>(new Rectangle(2, 2), Transform2D.DefaultTransform);
+            var line = new Line(new Position2D(-4, -4), new Position2D(4, 4));
+            var transformA = Transform2D.DefaultTransform;
+            var square = new Rectangle(-1, -1, 2, 2);
+            var transformB = Transform2D.DefaultTransform;
 
-            var (result, simplex) = NarrowPhase.FindCollisionSimplex(line, square);
+            var (result, simplex) = NarrowPhase.FindCollisionSimplex(line, transformA, square, transformB);
 
             result.Should().BeTrue();
 
-            var intersection = NarrowPhase.Intersect(line, square, simplex);
+            var intersection = NarrowPhase.Intersect(line, transformA, square, transformB, simplex);
 
-            var movedTransform = new Transform2D(-(intersection * 1.01f)); // move a tiny bit past
+            intersection.X.Should().Be(1);
+            intersection.Y.Should().Be(-1);
 
-            NarrowPhase.TestCollision(line.Compose(movedTransform), square).Should().BeFalse();
+            var movedTransform = new Transform2D(transformA.Position - (intersection * 2)); // move past
+
+            NarrowPhase.TestCollision(line, movedTransform, square, transformB).Should().BeFalse();
         }
     }
 }

Test/Equality.cs

@@ -1,8 +1,8 @@
 using NUnit.Framework;
 using FluentAssertions;
 
-using MoonTools.Core.Bonk;
-using MoonTools.Core.Structs;
+using MoonTools.Bonk;
+using MoonTools.Structs;
 using System.Numerics;
 using System.Collections.Immutable;
 
@@ -140,8 +140,8 @@ namespace Tests
             [Test]
             public void RectangleEqual()
             {
-                var a = new Rectangle(3, 3);
-                var b = new Rectangle(3, 3);
+                var a = new Rectangle(-1, -1, 3, 3);
+                var b = new Rectangle(-1, -1, 3, 3);
 
                 a.Equals(b).Should().BeTrue();
             }
@@ -149,8 +149,8 @@ namespace Tests
             [Test]
             public void RectangleEqualOperator()
             {
-                var a = new Rectangle(3, 3);
-                var b = new Rectangle(3, 3);
+                var a = new Rectangle(-1, -1, 3, 3);
+                var b = new Rectangle(-1, -1, 3, 3);
 
                 (a == b).Should().BeTrue();
             }
@@ -158,8 +158,8 @@ namespace Tests
             [Test]
             public void RectangleNotEqual()
             {
-                var a = new Rectangle(3, 3);
-                var b = new Rectangle(6, 6);
+                var a = new Rectangle(-1, -1, 3, 3);
+                var b = new Rectangle(-3, -3, 6, 6);
 
                 a.Equals(b).Should().BeFalse();
             }
@@ -167,8 +167,8 @@ namespace Tests
             [Test]
             public void RectangleNotEqualOperator()
             {
-                var a = new Rectangle(3, 3);
-                var b = new Rectangle(6, 6);
+                var a = new Rectangle(-1, -1, 3, 3);
+                var b = new Rectangle(-3, -3, 6, 6);
 
                 (a != b).Should().BeTrue();
             }

Test/NarrowPhaseTest.cs

@@ -1,6 +1,6 @@
 using NUnit.Framework;
-using MoonTools.Core.Bonk;
-using MoonTools.Core.Structs;
+using MoonTools.Bonk;
+using MoonTools.Structs;
 using System.Numerics;
 using FluentAssertions;
 using System.Collections.Immutable;
@@ -55,7 +55,7 @@ namespace Tests
         public void PointRectangleOverlapping()
         {
             var point = new Point();
-            var rectangle = new Rectangle(4, 4);
+            var rectangle = new Rectangle(-2, -2, 4, 4);
 
             NarrowPhase.TestCollision(point, Transform2D.DefaultTransform, rectangle, Transform2D.DefaultTransform).Should().BeTrue();
         }
@@ -65,7 +65,7 @@ namespace Tests
         {
             var point = new Point();
             var pointTransform = new Transform2D(new Position2D(5, 5));
-            var rectangle = new Rectangle(4, 4);
+            var rectangle = new Rectangle(-2, -2, 4, 4);
 
             NarrowPhase.TestCollision(point, pointTransform, rectangle, Transform2D.DefaultTransform).Should().BeFalse();
         }
@@ -354,10 +354,10 @@ namespace Tests
         [Test]
         public void RectanglesNotOverlapping()
         {
-            var rectangleA = new Rectangle(12, 12);
+            var rectangleA = new Rectangle(-6, -6, 12, 12);
             var transformA = new Transform2D(new Position2D(39, 249));
 
-            var rectangleB = new Rectangle(16, 16);
+            var rectangleB = new Rectangle(-8, -8, 16, 16);
             var transformB = new Transform2D(new Position2D(16, 240));
 
             NarrowPhase.TestCollision(rectangleA, transformA, rectangleB, transformB).Should().BeFalse();
@@ -366,10 +366,10 @@ namespace Tests
         [Test]
         public void RotatedRectanglesOverlapping()
         {
-            var rectangleA = new Rectangle(3, 6);
+            var rectangleA = new Rectangle(-1, -3, 3, 6);
             var transformA = new Transform2D(new Vector2(4f, 0), (float)System.Math.PI / 2);
 
-            var rectangleB = new Rectangle(2, 2);
+            var rectangleB = new Rectangle(-1, -1, 2, 2);
             var transformB = new Transform2D(new Vector2(0, 0));
 
             NarrowPhase.TestCollision(rectangleA, transformA, rectangleB, transformB).Should().BeTrue();
@@ -378,10 +378,10 @@ namespace Tests
         [Test]
         public void RectanglesTouchingGJK2D()
         {
-            var rectangleA = new Rectangle(2, 2);
+            var rectangleA = new Rectangle(-1, -1, 2, 2);
             var transformA = new Transform2D(new Position2D(-1, 0));
 
-            var rectangleB = new Rectangle(2, 2);
+            var rectangleB = new Rectangle(-1, -1, 2, 2);
             var transformB = new Transform2D(new Vector2(1, 0));
 
             NarrowPhase.TestCollision(rectangleA, transformA, rectangleB, transformB).Should().BeTrue();
@@ -390,10 +390,10 @@ namespace Tests
         [Test]
         public void RectanglesOverlappingGJK2D()
         {
-            var rectangleA = new Rectangle(2, 2);
+            var rectangleA = new Rectangle(-1, -1, 2, 2);
             var transformA = new Transform2D(new Position2D(0, 0));
 
-            var rectangleB = new Rectangle(2, 2);
+            var rectangleB = new Rectangle(-1, -1, 2, 2);
             var transformB = new Transform2D(new Vector2(1, 0));
 
             NarrowPhase.TestCollision(rectangleA, transformA, rectangleB, transformB).Should().BeTrue();
@@ -402,44 +402,44 @@ namespace Tests
         [Test]
         public void RectanglesTouchingOverlap()
         {
-            var rectangleA = new Rectangle(2, 2);
+            var rectangleA = new Rectangle(-1, -1, 2, 2);
             var transformA = new Transform2D(new Position2D(-1, 0));
 
-            var rectangleB = new Rectangle(2, 2);
+            var rectangleB = new Rectangle(-1, -1, 2, 2);
             var transformB = new Transform2D(new Vector2(1, 0));
 
-            NarrowPhase.TestCollision(new TransformedShape2D<Rectangle>(rectangleA, transformA), new TransformedShape2D<Rectangle>(rectangleB, transformB)).Should().BeTrue();
+            NarrowPhase.TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB).Should().BeTrue();
         }
 
         [Test]
         public void RectanglesOverlappingOverlap()
         {
-            var rectangleA = new Rectangle(2, 2);
+            var rectangleA = new Rectangle(-1, -1, 2, 2);
             var transformA = new Transform2D(new Position2D(0, 0));
 
-            var rectangleB = new Rectangle(2, 2);
-            var transformB = new Transform2D(new Vector2(1, 0));
+            var rectangleB = new Rectangle(-1, -1, 2, 2);
+            var transformB = new Transform2D(new Vector2(1, 0), 0, new Vector2(-1, 1));
 
-            NarrowPhase.TestCollision(new TransformedShape2D<Rectangle>(rectangleA, transformA), new TransformedShape2D<Rectangle>(rectangleB, transformB)).Should().BeTrue();
+            NarrowPhase.TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB).Should().BeTrue();
         }
 
         [Test]
         public void MultiRectanglesOverlapping()
         {
-            var multiRectangleA = new MultiShape<Rectangle>(
-                ImmutableArray.Create(
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 0))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 1))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 2)))
+            var multiRectangleA = new MultiShape(
+                ImmutableArray.Create<(IShape2D, Transform2D)>(
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-5, 0))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-5, 1))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-5, 2)))
                 )
             );
             var transformA = new Transform2D(new Position2D(5, 0));
 
-            var multiRectangleB = new MultiShape<Rectangle>(
-                ImmutableArray.Create(
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(4, -1))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(4, 0))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(4, 1)))
+            var multiRectangleB = new MultiShape(
+                ImmutableArray.Create<(IShape2D, Transform2D)>(
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(4, -1))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(4, 0))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(4, 1)))
                 )
             );
             var transformB = new Transform2D(new Position2D(0, 3));
@@ -450,30 +450,25 @@ namespace Tests
         [Test]
         public void MultiRectanglesNotOverlapping()
         {
-            var multiRectangleA = new MultiShape<Rectangle>(
-                ImmutableArray.Create(
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 0))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 1))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 2)))
+            var multiRectangleA = new MultiShape(
+                ImmutableArray.Create<(IShape2D, Transform2D)>(
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-5, 0))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-5, 1))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-5, 2)))
                 )
             );
             var transformA = new Transform2D(new Position2D(5, 0));
 
-            var multiRectangleB = new MultiShape<Rectangle>(
-                ImmutableArray.Create(
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(4, -1))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(4, 0))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(4, 1)))
+            var multiRectangleB = new MultiShape(
+                ImmutableArray.Create<(IShape2D, Transform2D)>(
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(4, -1))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(4, 0))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(4, 1)))
                 )
             );
             var transformB = new Transform2D(new Position2D(0, -3));
 
             NarrowPhase.TestCollision(multiRectangleA, transformA, multiRectangleB, transformB).Should().BeFalse();
         }
-
-        public class SweepTest
-        {
-
-        }
     }
 }

Test/SpatialHashTest.cs

@@ -1,7 +1,7 @@
 using FluentAssertions;
 using NUnit.Framework;
-using MoonTools.Core.Structs;
-using MoonTools.Core.Bonk;
+using MoonTools.Structs;
+using MoonTools.Bonk;
 using System.Numerics;
 using System.Collections.Immutable;
 
@@ -14,16 +14,16 @@ namespace Tests
         {
             var spatialHash = new SpatialHash<int>(16);
 
-            var rectA = new Rectangle(4, 4);
+            var rectA = new Rectangle(-2, -2, 4, 4);
             var rectATransform = new Transform2D(new Vector2(-8, -8));
 
-            var rectB = new Rectangle(4, 4);
+            var rectB = new Rectangle(-2, -2, 4, 4);
             var rectBTransform = new Transform2D(new Vector2(8, 8));
 
-            var rectC = new Rectangle(4, 4);
+            var rectC = new Rectangle(-2, -2, 4, 4);
             var rectCTransform = new Transform2D(new Vector2(24, -4));
 
-            var rectD = new Rectangle(4, 4);
+            var rectD = new Rectangle(-2, -2, 4, 4);
             var rectDTransform = new Transform2D(new Vector2(24, 24));
 
             var circleA = new Circle(2);
@@ -38,11 +38,11 @@ namespace Tests
             var point = new Point();
             var pointTransform = new Transform2D(new Position2D(8, 8));
 
-            var multiRectangle = new MultiShape<Rectangle>(
-                ImmutableArray.Create(
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-2, -2))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-2, -1))),
-                    (new Rectangle(4, 1), new Transform2D(new Position2D(-2, 0)))
+            var multiRectangle = new MultiShape(
+                ImmutableArray.Create<(IShape2D, Transform2D)>(
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-2, -2))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-2, -1))),
+                    (new Rectangle(-2, 0, 4, 1), new Transform2D(new Position2D(-2, 0)))
                 )
             );
             var multiRectangleTransform = new Transform2D(new Position2D(8, 8));
@@ -78,13 +78,13 @@ namespace Tests
         {
             var spatialHash = new SpatialHash<int>(16);
 
-            var rectA = new Rectangle(4, 4);
+            var rectA = new Rectangle(-2, -2, 4, 4);
             var rectATransform = new Transform2D(new Vector2(-8, -8));
 
-            var rectB = new Rectangle(4, 4);
+            var rectB = new Rectangle(-2, -2, 4, 4);
             var rectBTransform = new Transform2D(new Vector2(-8, -8));
 
-            var rectC = new Rectangle(2, 2);
+            var rectC = new Rectangle(-2, -2, 2, 2);
             var rectCTransform = new Transform2D(new Vector2(-8, -8));
 
             spatialHash.Insert(0, rectA, rectATransform);
@@ -99,10 +99,10 @@ namespace Tests
         {
             var spatialHash = new SpatialHash<int>(16);
 
-            var rectA = new Rectangle(4, 4);
+            var rectA = new Rectangle(-2, -2, 4, 4);
             var rectATransform = new Transform2D(new Vector2(-8, -8));
 
-            var rectB = new Rectangle(4, 4);
+            var rectB = new Rectangle(-2, -2, 4, 4);
             var rectBTransform = new Transform2D(new Vector2(8, 8));
 
             spatialHash.Insert(0, rectA, rectATransform);

Test/SweepTestTest.cs

@@ -1,7 +1,7 @@
 using System.Numerics;
 using FluentAssertions;
-using MoonTools.Core.Bonk;
-using MoonTools.Core.Structs;
+using MoonTools.Bonk;
+using MoonTools.Structs;
 using NUnit.Framework;
 
 namespace Tests
@@ -11,24 +11,32 @@ namespace Tests
         [Test]
         public void SweepsThrough()
         {
-            var rectangle = new Rectangle(4, 4);
+            var rectangle = new Rectangle(-2, -2, 4, 4);
             var transform = new Transform2D(new Position2D(-6, 0));
 
-            var otherRectangle = new Rectangle(4, 4);
+            var otherRectangle = new Rectangle(-2, -2, 4, 4);
             var otherTransform = new Transform2D(new Position2D(6, 0));
 
-            var farthestRectangle = new Rectangle(4, 4);
+            var farthestRectangle = new Rectangle(-2, -2, 4, 4);
             var farthestTransform = new Transform2D(new Position2D(12, 0));
 
+            var downRectangle = new Rectangle(-6, -2, 12, 4);
+            var downTransform = new Transform2D(new Position2D(-6, 20));
+
             var spatialHash = new SpatialHash<int>(16);
             spatialHash.Insert(1, otherRectangle, otherTransform);
             spatialHash.Insert(2, farthestRectangle, farthestTransform);
+            spatialHash.Insert(3, downRectangle, downTransform);
 
-            SweepTest.Rectangle(spatialHash, rectangle, transform, new Vector2(12, 0)).Should().Be(
-                new SweepResult<int, Rectangle>(true, new Vector2(8, 0), 1, otherRectangle, otherTransform)
+            SweepTest.Test(spatialHash, rectangle, transform, new Vector2(12, 0)).Should().Be(
+                new SweepResult<int>(true, new Vector2(7, 0), 1)
             );
 
-            SweepTest.Rectangle(spatialHash, rectangle, transform, new Vector2(-12, 0)).Hit.Should().BeFalse();
+            SweepTest.Test(spatialHash, rectangle, transform, new Vector2(-12, 0)).Hit.Should().BeFalse();
+
+            SweepTest.Test(spatialHash, rectangle, transform, new Vector2(0, 20)).Should().Be(
+                new SweepResult<int>(true, new Vector2(0, 15), 3)
+            );
         }
     }
 }