testing generic transformed shapes

generics
Evan Hemsley 2020-01-04 23:24:36 -08:00
parent 9777429d07
commit 4106a76ac9
11 changed files with 275 additions and 167 deletions

View File

@ -14,7 +14,7 @@ namespace MoonTools.Core.Bonk
private readonly int cellSize; private readonly int cellSize;
private readonly Dictionary<long, HashSet<T>> hashDictionary = new Dictionary<long, HashSet<T>>(); private readonly Dictionary<long, HashSet<T>> hashDictionary = new Dictionary<long, HashSet<T>>();
private readonly Dictionary<T, (IHasAABB2D, Transform2D)> IDLookup = new Dictionary<T, (IHasAABB2D, Transform2D)>(); private readonly Dictionary<T, IHasAABB2D> IDLookup = new Dictionary<T, IHasAABB2D>();
public SpatialHash(int cellSize) public SpatialHash(int cellSize)
{ {
@ -31,10 +31,9 @@ namespace MoonTools.Core.Bonk
/// </summary> /// </summary>
/// <param name="id">A unique ID for the shape-transform pair.</param> /// <param name="id">A unique ID for the shape-transform pair.</param>
/// <param name="shape"></param> /// <param name="shape"></param>
/// <param name="transform2D"></param> public void Insert(T id, IHasAABB2D shape)
public void Insert(T id, IHasAABB2D shape, Transform2D transform2D)
{ {
var box = shape.TransformedAABB(transform2D); var box = shape.AABB;
var minHash = Hash(box.Min); var minHash = Hash(box.Min);
var maxHash = Hash(box.Max); var maxHash = Hash(box.Max);
@ -57,9 +56,9 @@ namespace MoonTools.Core.Bonk
/// <summary> /// <summary>
/// Retrieves all the potential collisions of a shape-transform pair. Excludes any shape-transforms with the given ID. /// Retrieves all the potential collisions of a shape-transform pair. Excludes any shape-transforms with the given ID.
/// </summary> /// </summary>
public IEnumerable<(T, IHasAABB2D, Transform2D)> Retrieve(T id, IHasAABB2D shape, Transform2D transform2D) public IEnumerable<(T, IHasAABB2D)> Retrieve(T id, IHasAABB2D shape)
{ {
var box = shape.TransformedAABB(transform2D); var box = shape.AABB;
var minHash = Hash(box.Min); var minHash = Hash(box.Min);
var maxHash = Hash(box.Max); var maxHash = Hash(box.Max);
@ -72,10 +71,40 @@ namespace MoonTools.Core.Bonk
{ {
foreach (var t in hashDictionary[key]) foreach (var t in hashDictionary[key])
{ {
var (otherShape, otherTransform) = IDLookup[t]; var otherShape = IDLookup[t];
if (!id.Equals(t) && AABB.TestOverlap(shape.TransformedAABB(transform2D), otherShape.TransformedAABB(otherTransform))) if (!id.Equals(t) && AABB.TestOverlap(shape.AABB, otherShape.AABB))
{ {
yield return (t, otherShape, otherTransform); yield return (t, otherShape);
}
}
}
}
}
}
/// <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)
{
var minHash = Hash(aabb.Min);
var maxHash = Hash(aabb.Max);
for (var i = minHash.Item1; i <= maxHash.Item1; i++)
{
for (var j = minHash.Item2; j <= maxHash.Item2; 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))
{
yield return (t, otherShape);
} }
} }
} }

View File

@ -0,0 +1,15 @@
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; }
}
}

View File

@ -1,17 +1,7 @@
using System; namespace MoonTools.Core.Bonk
using MoonTools.Core.Structs;
namespace MoonTools.Core.Bonk
{ {
public interface IHasAABB2D public interface IHasAABB2D
{ {
AABB AABB { get; } 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);
} }
} }

View File

@ -13,5 +13,7 @@ namespace MoonTools.Core.Bonk
/// <param name="transform">A Transform for transforming the shape vertices.</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> /// <returns>The farthest point on the edge of the shape along the given direction.</returns>
Vector2 Support(Vector2 direction, Transform2D transform); Vector2 Support(Vector2 direction, Transform2D transform);
AABB TransformedAABB(Transform2D transform);
} }
} }

View File

@ -1,57 +1,50 @@
using System; using System;
using System.Numerics; using System.Numerics;
using MoonTools.Core.Structs;
namespace MoonTools.Core.Bonk namespace MoonTools.Core.Bonk
{ {
/// <summary> /// <summary>
/// A Minkowski difference between two shapes. /// A Minkowski difference between two shapes.
/// </summary> /// </summary>
public struct MinkowskiDifference : IEquatable<MinkowskiDifference> public struct MinkowskiDifference<T, U> : IEquatable<MinkowskiDifference<T, U>> where T : struct, IShape2D where U : struct, IShape2D
{ {
private IShape2D ShapeA { get; } private TransformedShape2D<T> ShapeA { get; }
private Transform2D TransformA { get; } private TransformedShape2D<U> ShapeB { get; }
private IShape2D ShapeB { get; }
private Transform2D TransformB { get; }
public MinkowskiDifference(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB) public MinkowskiDifference(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB)
{ {
ShapeA = shapeA; ShapeA = shapeA;
TransformA = transformA;
ShapeB = shapeB; ShapeB = shapeB;
TransformB = transformB;
} }
public Vector2 Support(Vector2 direction) public Vector2 Support(Vector2 direction)
{ {
return ShapeA.Support(direction, TransformA) - ShapeB.Support(-direction, TransformB); return ShapeA.Support(direction) - ShapeB.Support(-direction);
} }
public override bool Equals(object other) public override bool Equals(object other)
{ {
return other is MinkowskiDifference minkowskiDifference && Equals(minkowskiDifference); return other is MinkowskiDifference<T, U> minkowskiDifference && Equals(minkowskiDifference);
} }
public bool Equals(MinkowskiDifference other) public bool Equals(MinkowskiDifference<T, U> other)
{ {
return return
ShapeA == other.ShapeA && ShapeA == other.ShapeA &&
TransformA == other.TransformA && ShapeB == other.ShapeB;
ShapeB == other.ShapeB &&
TransformB == other.TransformB;
} }
public override int GetHashCode() public override int GetHashCode()
{ {
return HashCode.Combine(ShapeA, TransformA, ShapeB, TransformB); return HashCode.Combine(ShapeA, ShapeB);
} }
public static bool operator ==(MinkowskiDifference a, MinkowskiDifference b) public static bool operator ==(MinkowskiDifference<T, U> a, MinkowskiDifference<T, U> b)
{ {
return a.Equals(b); return a.Equals(b);
} }
public static bool operator !=(MinkowskiDifference a, MinkowskiDifference b) public static bool operator !=(MinkowskiDifference<T, U> a, MinkowskiDifference<T, U> b)
{ {
return !(a == b); return !(a == b);
} }

View File

@ -4,17 +4,30 @@ using MoonTools.Core.Structs;
namespace MoonTools.Core.Bonk namespace MoonTools.Core.Bonk
{ {
public struct MultiShape : IHasAABB2D public struct MultiShape<TShape2D> : IHasAABB2D, ICollisionTestable<TShape2D> where TShape2D : struct, IShape2D
{ {
public ImmutableArray<(IShape2D, Transform2D)> ShapeTransformPairs { get; } 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 AABB AABB { get; } public AABB AABB { get; }
public MultiShape(ImmutableArray<(IShape2D, Transform2D)> shapeTransformPairs) public MultiShape(ImmutableArray<(TShape2D, Transform2D)> shapeTransformPairs)
{ {
ShapeTransformPairs = shapeTransformPairs; _builder.Clear();
foreach (var (shape, transform) in shapeTransformPairs)
{
_builder.Add(new TransformedShape2D<TShape2D>(shape, transform));
}
AABB = AABBFromShapes(shapeTransformPairs); _transformedShapes = _builder.ToImmutable();
AABB = AABBFromShapes(_transformedShapes);
}
public MultiShape(ImmutableArray<TransformedShape2D<TShape2D>> transformedShapes)
{
_transformedShapes = transformedShapes;
AABB = AABBFromShapes(transformedShapes);
} }
public AABB TransformedAABB(Transform2D transform) public AABB TransformedAABB(Transform2D transform)
@ -22,24 +35,24 @@ namespace MoonTools.Core.Bonk
return AABB.Transformed(AABB, transform); return AABB.Transformed(AABB, transform);
} }
public IEnumerable<(IShape2D, Transform2D)> TransformedShapeTransforms(Transform2D transform) public IEnumerable<TransformedShape2D<TShape2D>> Compose(Transform2D transform)
{ {
foreach (var (shape, shapeTransform) in ShapeTransformPairs) foreach (var transformedShape in TransformedShapes)
{ {
yield return (shape, transform.Compose(shapeTransform)); yield return transformedShape.Compose(transform);
} }
} }
private static AABB AABBFromShapes(IEnumerable<(IShape2D, Transform2D)> shapeTransforms) private static AABB AABBFromShapes(IEnumerable<TransformedShape2D<TShape2D>> transformedShapes)
{ {
var minX = float.MaxValue; var minX = float.MaxValue;
var minY = float.MaxValue; var minY = float.MaxValue;
var maxX = float.MinValue; var maxX = float.MinValue;
var maxY = float.MinValue; var maxY = float.MinValue;
foreach (var (shape, transform) in shapeTransforms) foreach (var transformedShape in transformedShapes)
{ {
var aabb = shape.TransformedAABB(transform); var aabb = transformedShape.AABB;
if (aabb.Min.X < minX) if (aabb.Min.X < minX)
{ {

View File

@ -1,4 +1,6 @@
using MoonTools.Core.Structs; using MoonTools.Core.Structs;
using System;
using System.Collections.Generic;
using System.Numerics; using System.Numerics;
namespace MoonTools.Core.Bonk namespace MoonTools.Core.Bonk
@ -11,52 +13,37 @@ namespace MoonTools.Core.Bonk
CounterClockwise CounterClockwise
} }
/// <summary> public static bool TestCollision<T, U>(ICollisionTestable<T> a, ICollisionTestable<U> b) where T : struct, IShape2D where U : struct, IShape2D
/// 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)
{ {
if (hasBoundingBoxA is MultiShape && hasBoundingBoxB is MultiShape) foreach (var shape in a.TransformedShapes)
{ {
return TestCollision((MultiShape)hasBoundingBoxA, transformA, (MultiShape)hasBoundingBoxB, transformB); foreach (var shapeB in b.TransformedShapes)
{
return TestCollision(shape, shapeB);
} }
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;
} }
public static bool TestCollision(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB) /// <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
{ {
if (shapeA is Rectangle rectangleA && shapeB is Rectangle rectangleB && transformA.Rotation == 0 && transformB.Rotation == 0) return TestCollision(new TransformedShape2D<T>(shape, transform), new TransformedShape2D<U>(shapeB, transformB));
{
return TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB);
} }
else if (shapeA is Point && shapeB is Rectangle && transformB.Rotation == 0)
/// <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
{ {
return TestPointRectangleOverlap((Point)shapeA, transformA, (Rectangle)shapeB, transformB); return FindCollisionSimplex(transformedShapeA, transformedShapeB).Item1;
}
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> /// <summary>
@ -66,13 +53,21 @@ namespace MoonTools.Core.Bonk
/// <param name="multiShape"></param> /// <param name="multiShape"></param>
/// <param name="multiShapeTransform"></param> /// <param name="multiShapeTransform"></param>
/// <param name="shape"></param> /// <param name="shape"></param>
/// <param name="shapeTransform"></param>
/// <returns></returns> /// <returns></returns>
public static bool TestCollision(MultiShape multiShape, Transform2D multiShapeTransform, IShape2D shape, Transform2D shapeTransform) public static bool TestCollision<T, U>(MultiShape<T> multiShape, Transform2D multiShapeTransform, TransformedShape2D<U> shape) where T : struct, IShape2D where U : struct, IShape2D
{ {
foreach (var (otherShape, otherTransform) in multiShape.ShapeTransformPairs) foreach (var transformedShape in multiShape.Compose(multiShapeTransform))
{ {
if (TestCollision(shape, shapeTransform, otherShape, multiShapeTransform.Compose(otherTransform))) { return true; } 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; }
} }
return false; return false;
} }
@ -84,15 +79,10 @@ namespace MoonTools.Core.Bonk
/// <param name="multiShape"></param> /// <param name="multiShape"></param>
/// <param name="multiShapeTransform"></param> /// <param name="multiShapeTransform"></param>
/// <param name="shape"></param> /// <param name="shape"></param>
/// <param name="shapeTransform"></param>
/// <returns></returns> /// <returns></returns>
public static bool TestCollision(IShape2D shape, Transform2D shapeTransform, MultiShape multiShape, Transform2D multiShapeTransform) public static bool TestCollision<T, U>(TransformedShape2D<T> shape, MultiShape<U> multiShape, Transform2D multiShapeTransform) where T : struct, IShape2D where U : struct, IShape2D
{ {
foreach (var (otherShape, otherTransform) in multiShape.ShapeTransformPairs) return TestCollision(multiShape, multiShapeTransform, shape);
{
if (TestCollision(shape, shapeTransform, otherShape, multiShapeTransform.Compose(otherTransform))) { return true; }
}
return false;
} }
/// <summary> /// <summary>
@ -104,13 +94,13 @@ namespace MoonTools.Core.Bonk
/// <param name="multiShapeB"></param> /// <param name="multiShapeB"></param>
/// <param name="transformB"></param> /// <param name="transformB"></param>
/// <returns></returns> /// <returns></returns>
public static bool TestCollision(MultiShape multiShapeA, Transform2D transformA, MultiShape multiShapeB, Transform2D transformB) public static bool TestCollision<T, U>(MultiShape<T> multiShapeA, Transform2D transformA, MultiShape<U> multiShapeB, Transform2D transformB) where T : struct, IShape2D where U : struct, IShape2D
{ {
foreach (var (shapeA, shapeTransformA) in multiShapeA.ShapeTransformPairs) foreach (var transformedShapeA in multiShapeA.Compose(transformA))
{ {
foreach (var (shapeB, shapeTransformB) in multiShapeB.ShapeTransformPairs) foreach (var transformedShapeB in multiShapeB.Compose(transformB))
{ {
if (TestCollision(shapeA, transformA.Compose(shapeTransformA), shapeB, transformB.Compose(shapeTransformB))) { return true; } if (TestCollision(transformedShapeA, transformedShapeB)) { return true; }
} }
} }
return false; return false;
@ -120,14 +110,12 @@ namespace MoonTools.Core.Bonk
/// Fast path for axis-aligned rectangles. If the transforms have non-zero rotation this will be inaccurate. /// Fast path for axis-aligned rectangles. If the transforms have non-zero rotation this will be inaccurate.
/// </summary> /// </summary>
/// <param name="rectangleA"></param> /// <param name="rectangleA"></param>
/// <param name="transformA"></param>
/// <param name="rectangleB"></param> /// <param name="rectangleB"></param>
/// <param name="transformB"></param>
/// <returns></returns> /// <returns></returns>
public static bool TestRectangleOverlap(Rectangle rectangleA, Transform2D transformA, Rectangle rectangleB, Transform2D transformB) public static bool TestCollision(TransformedShape2D<Rectangle> rectangleA, TransformedShape2D<Rectangle> rectangleB)
{ {
var firstAABB = rectangleA.TransformedAABB(transformA); var firstAABB = rectangleA.AABB;
var secondAABB = rectangleB.TransformedAABB(transformB); var secondAABB = rectangleB.AABB;
return firstAABB.Left <= secondAABB.Right && firstAABB.Right >= secondAABB.Left && firstAABB.Top <= secondAABB.Bottom && firstAABB.Bottom >= secondAABB.Top; return firstAABB.Left <= secondAABB.Right && firstAABB.Right >= secondAABB.Left && firstAABB.Top <= secondAABB.Bottom && firstAABB.Bottom >= secondAABB.Top;
} }
@ -136,33 +124,34 @@ namespace MoonTools.Core.Bonk
/// Fast path for overlapping point and axis-aligned rectangle. The rectangle transform must have non-zero rotation. /// Fast path for overlapping point and axis-aligned rectangle. The rectangle transform must have non-zero rotation.
/// </summary> /// </summary>
/// <param name="point"></param> /// <param name="point"></param>
/// <param name="pointTransform"></param>
/// <param name="rectangle"></param> /// <param name="rectangle"></param>
/// <param name="rectangleTransform"></param>
/// <returns></returns> /// <returns></returns>
public static bool TestPointRectangleOverlap(Point point, Transform2D pointTransform, Rectangle rectangle, Transform2D rectangleTransform) public static bool TestCollision(TransformedShape2D<Point> point, TransformedShape2D<Rectangle> rectangle)
{ {
var transformedPoint = pointTransform.Position; var transformedPoint = point.Transform.Position;
var AABB = rectangle.TransformedAABB(rectangleTransform); var AABB = rectangle.AABB;
return transformedPoint.X >= AABB.Left && transformedPoint.X <= AABB.Right && transformedPoint.Y <= AABB.Bottom && transformedPoint.Y >= AABB.Top; 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> /// <summary>
/// Fast path for overlapping circles. The circles must have uniform scaling. /// Fast path for overlapping circles. The circles must have uniform scaling.
/// </summary> /// </summary>
/// <param name="circleA"></param> /// <param name="circleA"></param>
/// <param name="transformA"></param>
/// <param name="circleB"></param> /// <param name="circleB"></param>
/// <param name="transformB"></param>
/// <returns></returns> /// <returns></returns>
public static bool TestCircleOverlap(Circle circleA, Transform2D transformA, Circle circleB, Transform2D transformB) public static bool TestCollision(TransformedShape2D<Circle> circleA, TransformedShape2D<Circle> circleB)
{ {
var radiusA = circleA.Radius * transformA.Scale.X; var radiusA = circleA.Shape.Radius * circleA.Transform.Scale.X;
var radiusB = circleB.Radius * transformB.Scale.Y; var radiusB = circleB.Shape.Radius * circleB.Transform.Scale.Y;
var centerA = transformA.Position; var centerA = circleA.Transform.Position;
var centerB = transformB.Position; var centerB = circleB.Transform.Position;
var distanceSquared = (centerA - centerB).LengthSquared(); var distanceSquared = (centerA - centerB).LengthSquared();
var radiusSumSquared = (radiusA + radiusB) * (radiusA + radiusB); var radiusSumSquared = (radiusA + radiusB) * (radiusA + radiusB);
@ -173,9 +162,9 @@ namespace MoonTools.Core.Bonk
/// <summary> /// <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. /// 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> /// </summary>
public static (bool, Simplex2D) FindCollisionSimplex(IShape2D shapeA, Transform2D transformA, IShape2D shapeB, Transform2D transformB) public static (bool, Simplex2D) FindCollisionSimplex<T, U>(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB) where T : struct, IShape2D where U : struct, IShape2D
{ {
var minkowskiDifference = new MinkowskiDifference(shapeA, transformA, shapeB, transformB); var minkowskiDifference = new MinkowskiDifference<T, U>(shapeA, shapeB);
var c = minkowskiDifference.Support(Vector2.UnitX); var c = minkowskiDifference.Support(Vector2.UnitX);
var b = minkowskiDifference.Support(-Vector2.UnitX); var b = minkowskiDifference.Support(-Vector2.UnitX);
return Check(minkowskiDifference, c, b); return Check(minkowskiDifference, c, b);
@ -185,7 +174,7 @@ namespace MoonTools.Core.Bonk
/// Returns a minimum separating vector in the direction from A to B. /// Returns a minimum separating vector in the direction from A to B.
/// </summary> /// </summary>
/// <param name="simplex">A simplex returned by the GJK algorithm.</param> /// <param name="simplex">A simplex returned by the GJK algorithm.</param>
public unsafe static Vector2 Intersect(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Simplex2D simplex) public unsafe static Vector2 Intersect<T, U>(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB, Simplex2D simplex) where T : struct, IShape2D where U : struct, IShape2D
{ {
if (shapeA == null) { throw new System.ArgumentNullException(nameof(shapeA)); } if (shapeA == null) { throw new System.ArgumentNullException(nameof(shapeA)); }
if (shapeB == null) { throw new System.ArgumentNullException(nameof(shapeB)); } if (shapeB == null) { throw new System.ArgumentNullException(nameof(shapeB)); }
@ -207,7 +196,7 @@ namespace MoonTools.Core.Bonk
for (var i = 0; i < 32; i++) for (var i = 0; i < 32; i++)
{ {
var edge = FindClosestEdge(winding, simplexVertices); var edge = FindClosestEdge(winding, simplexVertices);
var support = CalculateSupport(shapeA, Transform2DA, shapeB, Transform2DB, edge.normal); var support = CalculateSupport(shapeA, shapeB, edge.normal);
var distance = Vector2.Dot(support, edge.normal); var distance = Vector2.Dot(support, edge.normal);
intersection = edge.normal; intersection = edge.normal;
@ -261,12 +250,12 @@ namespace MoonTools.Core.Bonk
return new Edge(closestDistance, closestNormal, closestIndex); return new Edge(closestDistance, closestNormal, closestIndex);
} }
private static Vector2 CalculateSupport(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Vector2 direction) private static Vector2 CalculateSupport<T, U>(TransformedShape2D<T> shapeA, TransformedShape2D<U> shapeB, Vector2 direction) where T : struct, IShape2D where U : struct, IShape2D
{ {
return shapeA.Support(direction, Transform2DA) - shapeB.Support(-direction, Transform2DB); return shapeA.Support(direction) - shapeB.Support(-direction);
} }
private static (bool, Simplex2D) Check(MinkowskiDifference minkowskiDifference, Vector2 c, Vector2 b) private static (bool, Simplex2D) Check<T, U>(MinkowskiDifference<T, U> minkowskiDifference, Vector2 c, Vector2 b) where T : struct, IShape2D where U : struct, IShape2D
{ {
var cb = c - b; var cb = c - b;
var c0 = -c; var c0 = -c;
@ -274,7 +263,7 @@ namespace MoonTools.Core.Bonk
return DoSimplex(minkowskiDifference, new Simplex2D(b, c), d); return DoSimplex(minkowskiDifference, new Simplex2D(b, c), d);
} }
private static (bool, Simplex2D) DoSimplex(MinkowskiDifference minkowskiDifference, Simplex2D simplex, Vector2 direction) private static (bool, Simplex2D) DoSimplex<T, U>(MinkowskiDifference<T, U> minkowskiDifference, Simplex2D simplex, Vector2 direction) where T : struct, IShape2D where U : struct, IShape2D
{ {
var a = minkowskiDifference.Support(direction); var a = minkowskiDifference.Support(direction);
var notPastOrigin = Vector2.Dot(a, direction) < 0; var notPastOrigin = Vector2.Dot(a, direction) < 0;

View File

@ -0,0 +1,78 @@
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);
}
}
}

View File

@ -13,67 +13,61 @@ namespace Tests
[Test] [Test]
public void RectangleOverlap() public void RectangleOverlap()
{ {
var squareA = new Rectangle(2, 2); var squareA = new TransformedShape2D<Rectangle>(new Rectangle(2, 2), Transform2D.DefaultTransform);
var transformA = Transform2D.DefaultTransform; var squareB = new TransformedShape2D<Rectangle>(new Rectangle(2, 2), new Transform2D(new Vector2(1.5f, 0)));
var squareB = new Rectangle(2, 2);
var transformB = new Transform2D(new Vector2(1.5f, 0));
var (result, simplex) = NarrowPhase.FindCollisionSimplex(squareA, transformA, squareB, transformB); var (result, simplex) = NarrowPhase.FindCollisionSimplex(squareA, squareB);
result.Should().BeTrue(); result.Should().BeTrue();
var intersection = NarrowPhase.Intersect(squareA, transformA, squareB, transformB, simplex); var intersection = NarrowPhase.Intersect(squareA, squareB, simplex);
intersection.X.Should().Be(1f); intersection.X.Should().Be(1f);
intersection.Y.Should().Be(0); intersection.Y.Should().Be(0);
var movedTransform = new Transform2D(transformA.Position - (intersection * 1.01f)); // move a tiny bit past var movedTransform = new Transform2D(-(intersection * 1.01f)); // move a tiny bit past
NarrowPhase.TestCollision(squareA, movedTransform, squareB, transformB).Should().BeFalse(); NarrowPhase.TestCollision(squareA.Compose(movedTransform), squareB).Should().BeFalse();
} }
[Test] [Test]
public void CircleOverlap() public void CircleOverlap()
{ {
var circleA = new Circle(2); var circleA = new TransformedShape2D<Circle>(new Circle(2), Transform2D.DefaultTransform);
var transformA = Transform2D.DefaultTransform; var circleB = new TransformedShape2D<Circle>(new Circle(1), new Transform2D(new Vector2(1, 1)));
var circleB = new Circle(1);
var transformB = new Transform2D(new Vector2(1, 1));
var (result, simplex) = NarrowPhase.FindCollisionSimplex(circleA, transformA, circleB, transformB); var (result, simplex) = NarrowPhase.FindCollisionSimplex(circleA, circleB);
result.Should().BeTrue(); result.Should().BeTrue();
var intersection = NarrowPhase.Intersect(circleA, transformA, circleB, transformB, simplex); var intersection = NarrowPhase.Intersect(circleA, circleB, simplex);
var ix = (circleA.Radius * (float)Math.Cos(Math.PI / 4)) - ((circleB.Radius * (float)Math.Cos(5 * Math.PI / 4)) + transformB.Position.X); var ix = (2 * (float)Math.Cos(Math.PI / 4)) - ((1 * (float)Math.Cos(5 * Math.PI / 4)) + 1);
var iy = (circleA.Radius * (float)Math.Sin(Math.PI / 4)) - ((circleB.Radius * (float)Math.Sin(5 * Math.PI / 4)) + transformB.Position.Y); var iy = (2 * (float)Math.Sin(Math.PI / 4)) - ((1 * (float)Math.Sin(5 * Math.PI / 4)) + 1);
intersection.X.Should().BeApproximately(ix, 0.01f); intersection.X.Should().BeApproximately(ix, 0.01f);
intersection.Y.Should().BeApproximately(iy, 0.01f); intersection.Y.Should().BeApproximately(iy, 0.01f);
var movedTransform = new Transform2D(transformA.Position - (intersection * 1.01f)); // move a tiny bit past var movedTransform = new Transform2D(-(intersection * 1.01f)); // move a tiny bit past
NarrowPhase.TestCollision(circleA, movedTransform, circleB, transformB).Should().BeFalse(); NarrowPhase.TestCollision(circleA.Compose(movedTransform), circleB).Should().BeFalse();
} }
[Test] [Test]
public void LineRectangleOverlap() public void LineRectangleOverlap()
{ {
var line = new Line(new Position2D(-4, -4), new Position2D(4, 4)); var line = new TransformedShape2D<Line>(new Line(new Position2D(-4, -4), new Position2D(4, 4)), Transform2D.DefaultTransform);
var transformA = Transform2D.DefaultTransform; var square = new TransformedShape2D<Rectangle>(new Rectangle(2, 2), Transform2D.DefaultTransform);
var square = new Rectangle(2, 2);
var transformB = Transform2D.DefaultTransform;
var (result, simplex) = NarrowPhase.FindCollisionSimplex(line, transformA, square, transformB); var (result, simplex) = NarrowPhase.FindCollisionSimplex(line, square);
result.Should().BeTrue(); result.Should().BeTrue();
var intersection = NarrowPhase.Intersect(line, transformA, square, transformB, simplex); var intersection = NarrowPhase.Intersect(line, square, simplex);
var movedTransform = new Transform2D(transformA.Position - (intersection * 1.01f)); // move a tiny bit past var movedTransform = new Transform2D(-(intersection * 1.01f)); // move a tiny bit past
NarrowPhase.TestCollision(line, movedTransform, square, transformB).Should().BeFalse(); NarrowPhase.TestCollision(line.Compose(movedTransform), square).Should().BeFalse();
} }
} }
} }

View File

@ -408,7 +408,7 @@ namespace Tests
var rectangleB = new Rectangle(2, 2); var rectangleB = new Rectangle(2, 2);
var transformB = new Transform2D(new Vector2(1, 0)); var transformB = new Transform2D(new Vector2(1, 0));
NarrowPhase.TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB).Should().BeTrue(); NarrowPhase.TestCollision(new TransformedShape2D<Rectangle>(rectangleA, transformA), new TransformedShape2D<Rectangle>(rectangleB, transformB)).Should().BeTrue();
} }
[Test] [Test]
@ -420,14 +420,14 @@ namespace Tests
var rectangleB = new Rectangle(2, 2); var rectangleB = new Rectangle(2, 2);
var transformB = new Transform2D(new Vector2(1, 0)); var transformB = new Transform2D(new Vector2(1, 0));
NarrowPhase.TestRectangleOverlap(rectangleA, transformA, rectangleB, transformB).Should().BeTrue(); NarrowPhase.TestCollision(new TransformedShape2D<Rectangle>(rectangleA, transformA), new TransformedShape2D<Rectangle>(rectangleB, transformB)).Should().BeTrue();
} }
[Test] [Test]
public void MultiRectanglesOverlapping() public void MultiRectanglesOverlapping()
{ {
var multiRectangleA = new MultiShape( var multiRectangleA = new MultiShape<Rectangle>(
ImmutableArray.Create<(IShape2D, Transform2D)>( ImmutableArray.Create(
(new Rectangle(4, 1), new Transform2D(new Position2D(-5, 0))), (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, 1))),
(new Rectangle(4, 1), new Transform2D(new Position2D(-5, 2))) (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 2)))
@ -435,8 +435,8 @@ namespace Tests
); );
var transformA = new Transform2D(new Position2D(5, 0)); var transformA = new Transform2D(new Position2D(5, 0));
var multiRectangleB = new MultiShape( var multiRectangleB = new MultiShape<Rectangle>(
ImmutableArray.Create<(IShape2D, Transform2D)>( ImmutableArray.Create(
(new Rectangle(4, 1), new Transform2D(new Position2D(4, -1))), (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, 0))),
(new Rectangle(4, 1), new Transform2D(new Position2D(4, 1))) (new Rectangle(4, 1), new Transform2D(new Position2D(4, 1)))
@ -450,8 +450,8 @@ namespace Tests
[Test] [Test]
public void MultiRectanglesNotOverlapping() public void MultiRectanglesNotOverlapping()
{ {
var multiRectangleA = new MultiShape( var multiRectangleA = new MultiShape<Rectangle>(
ImmutableArray.Create<(IShape2D, Transform2D)>( ImmutableArray.Create(
(new Rectangle(4, 1), new Transform2D(new Position2D(-5, 0))), (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, 1))),
(new Rectangle(4, 1), new Transform2D(new Position2D(-5, 2))) (new Rectangle(4, 1), new Transform2D(new Position2D(-5, 2)))
@ -459,8 +459,8 @@ namespace Tests
); );
var transformA = new Transform2D(new Position2D(5, 0)); var transformA = new Transform2D(new Position2D(5, 0));
var multiRectangleB = new MultiShape( var multiRectangleB = new MultiShape<Rectangle>(
ImmutableArray.Create<(IShape2D, Transform2D)>( ImmutableArray.Create(
(new Rectangle(4, 1), new Transform2D(new Position2D(4, -1))), (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, 0))),
(new Rectangle(4, 1), new Transform2D(new Position2D(4, 1))) (new Rectangle(4, 1), new Transform2D(new Position2D(4, 1)))
@ -470,5 +470,10 @@ namespace Tests
NarrowPhase.TestCollision(multiRectangleA, transformA, multiRectangleB, transformB).Should().BeFalse(); NarrowPhase.TestCollision(multiRectangleA, transformA, multiRectangleB, transformB).Should().BeFalse();
} }
public class SweepTest
{
}
} }
} }

View File

@ -38,8 +38,8 @@ namespace Tests
var point = new Point(); var point = new Point();
var pointTransform = new Transform2D(new Position2D(8, 8)); var pointTransform = new Transform2D(new Position2D(8, 8));
var multiRectangle = new MultiShape( var multiRectangle = new MultiShape<Rectangle>(
ImmutableArray.Create<(IShape2D, Transform2D)>( ImmutableArray.Create(
(new Rectangle(4, 1), new Transform2D(new Position2D(-2, -2))), (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, -1))),
(new Rectangle(4, 1), new Transform2D(new Position2D(-2, 0))) (new Rectangle(4, 1), new Transform2D(new Position2D(-2, 0)))