polygon with immutable array

generics
Evan Hemsley 2019-12-01 21:51:52 -08:00
parent b1a3e37a9d
commit 1430047327
6 changed files with 109 additions and 30 deletions

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@ -17,6 +17,6 @@
<ItemGroup> <ItemGroup>
<PackageReference Include="MoonTools.Core.Structs" Version="2.0.0"/> <PackageReference Include="MoonTools.Core.Structs" Version="2.0.0"/>
<PackageReference Include="morelinq" Version="3.2.0"/> <PackageReference Include="morelinq" Version="3.2.0"/>
<PackageReference Include="Collections.Pooled" Version="1.0.82"/> <PackageReference Include="System.Collections.Immutable" Version="1.6.0"/>
</ItemGroup> </ItemGroup>
</Project> </Project>

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@ -4,9 +4,10 @@
* https://blog.hamaluik.ca/posts/building-a-collision-engine-part-2-2d-penetration-vectors/ * https://blog.hamaluik.ca/posts/building-a-collision-engine-part-2-2d-penetration-vectors/
*/ */
using Collections.Pooled;
using MoonTools.Core.Structs; using MoonTools.Core.Structs;
using System; using System;
using System.Collections.Immutable;
using System.Linq;
using System.Numerics; using System.Numerics;
namespace MoonTools.Core.Bonk namespace MoonTools.Core.Bonk
@ -26,12 +27,7 @@ namespace MoonTools.Core.Bonk
/// <returns></returns> /// <returns></returns>
public static Vector2 Intersect(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Simplex2D simplex) public static Vector2 Intersect(IShape2D shapeA, Transform2D Transform2DA, IShape2D shapeB, Transform2D Transform2DB, Simplex2D simplex)
{ {
var simplexVertices = new PooledList<Vector2>(36, ClearMode.Always); var simplexVertices = simplex.Vertices.Select(vertex => vertex.ToVector2()).ToImmutableArray();
foreach (var vertex in simplex.Vertices)
{
simplexVertices.Add(vertex);
}
var e0 = (simplexVertices[1].X - simplexVertices[0].X) * (simplexVertices[1].Y + simplexVertices[0].Y); var e0 = (simplexVertices[1].X - simplexVertices[0].X) * (simplexVertices[1].Y + simplexVertices[0].Y);
var e1 = (simplexVertices[2].X - simplexVertices[1].X) * (simplexVertices[2].Y + simplexVertices[1].Y); var e1 = (simplexVertices[2].X - simplexVertices[1].X) * (simplexVertices[2].Y + simplexVertices[1].Y);
@ -55,25 +51,23 @@ namespace MoonTools.Core.Bonk
} }
else else
{ {
simplexVertices.Insert(edge.index, support); simplexVertices = simplexVertices.Insert(edge.index, support);
} }
} }
simplexVertices.Dispose();
return intersection; return intersection;
} }
private static Edge FindClosestEdge(PolygonWinding winding, PooledList<Vector2> simplexVertices) private static Edge FindClosestEdge(PolygonWinding winding, ImmutableArray<Vector2> simplexVertices)
{ {
var closestDistance = float.PositiveInfinity; var closestDistance = float.PositiveInfinity;
var closestNormal = Vector2.Zero; var closestNormal = Vector2.Zero;
var closestIndex = 0; var closestIndex = 0;
for (int i = 0; i < simplexVertices.Count; i++) for (int i = 0; i < simplexVertices.Length; i++)
{ {
var j = i + 1; var j = i + 1;
if (j >= simplexVertices.Count) { j = 0; } if (j >= simplexVertices.Length) { j = 0; }
Vector2 edge = simplexVertices[j] - simplexVertices[i]; Vector2 edge = simplexVertices[j] - simplexVertices[i];
Vector2 norm; Vector2 norm;

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@ -13,7 +13,7 @@ namespace MoonTools.Core.Bonk
private Position2D v0; private Position2D v0;
private Position2D v1; private Position2D v1;
private IEnumerable<Position2D> vertices private IEnumerable<Position2D> Vertices
{ {
get get
{ {
@ -39,7 +39,7 @@ namespace MoonTools.Core.Bonk
public AABB AABB(Transform2D Transform2D) public AABB AABB(Transform2D Transform2D)
{ {
return Bonk.AABB.FromTransformedVertices(vertices, Transform2D); return Bonk.AABB.FromTransformedVertices(Vertices, Transform2D);
} }
public override bool Equals(object obj) public override bool Equals(object obj)
@ -67,7 +67,7 @@ namespace MoonTools.Core.Bonk
var hashCode = -851829407; var hashCode = -851829407;
hashCode = hashCode * -1521134295 + EqualityComparer<Position2D>.Default.GetHashCode(v0); hashCode = hashCode * -1521134295 + EqualityComparer<Position2D>.Default.GetHashCode(v0);
hashCode = hashCode * -1521134295 + EqualityComparer<Position2D>.Default.GetHashCode(v1); hashCode = hashCode * -1521134295 + EqualityComparer<Position2D>.Default.GetHashCode(v1);
hashCode = hashCode * -1521134295 + EqualityComparer<IEnumerable<Position2D>>.Default.GetHashCode(vertices); hashCode = hashCode * -1521134295 + EqualityComparer<IEnumerable<Position2D>>.Default.GetHashCode(Vertices);
return hashCode; return hashCode;
} }

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@ -1,26 +1,32 @@
using System.Linq; using System.Linq;
using System; using System;
using System.Collections.Generic; using System.Collections.Generic;
using System.Collections.Immutable;
using System.Numerics; using System.Numerics;
using Collections.Pooled;
using MoonTools.Core.Structs; using MoonTools.Core.Structs;
using MoreLinq; using MoreLinq;
namespace MoonTools.Core.Bonk namespace MoonTools.Core.Bonk
{ {
/// <summary> /// <summary>
/// A Shape defined by an arbitrary collection of vertices. WARNING: Polygon must use an Array internally and therefore will create GC pressure. /// A Shape defined by an arbitrary collection of vertices.
/// NOTE: A Polygon must have more than 2 vertices and should not have duplicate vertices.
/// </summary> /// </summary>
public struct Polygon : IShape2D, IEquatable<IShape2D> public struct Polygon : IShape2D, IEquatable<IShape2D>
{ {
private PooledSet<Position2D> vertices; private ImmutableArray<Position2D> vertices;
public IEnumerable<Position2D> Vertices { get { return vertices == null ? Enumerable.Empty<Position2D>() : vertices; } } public IEnumerable<Position2D> Vertices { get { return vertices == null ? Enumerable.Empty<Position2D>() : vertices; } }
// vertices are local to the origin // vertices are local to the origin
public Polygon(params Position2D[] vertices) public Polygon(params Position2D[] vertices)
{ {
this.vertices = new PooledSet<Position2D>(vertices, ClearMode.Always); this.vertices = ImmutableArray.Create<Position2D>(vertices);
}
public Polygon(ImmutableArray<Position2D> vertices)
{
this.vertices = vertices;
} }
public Vector2 Support(Vector2 direction, Transform2D transform) public Vector2 Support(Vector2 direction, Transform2D transform)
@ -47,7 +53,19 @@ namespace MoonTools.Core.Bonk
{ {
if (other is Polygon otherPolygon) if (other is Polygon otherPolygon)
{ {
return vertices.SetEquals(otherPolygon.vertices); var q = from a in vertices
join b in otherPolygon.vertices on a equals b
select a;
return vertices.Length == otherPolygon.vertices.Length && q.Count() == vertices.Length;
}
else if (other is Rectangle rectangle)
{
var q = from a in vertices
join b in rectangle.Vertices on a equals b
select a;
return vertices.Length == 4 && q.Count() == vertices.Length;
} }
return false; return false;
@ -55,10 +73,7 @@ namespace MoonTools.Core.Bonk
public override int GetHashCode() public override int GetHashCode()
{ {
var hashCode = -1404792980; return HashCode.Combine(vertices, Vertices);
hashCode = hashCode * -1521134295 + EqualityComparer<PooledSet<Position2D>>.Default.GetHashCode(vertices);
hashCode = hashCode * -1521134295 + EqualityComparer<IEnumerable<Position2D>>.Default.GetHashCode(Vertices);
return hashCode;
} }
public static bool operator ==(Polygon a, Polygon b) public static bool operator ==(Polygon a, Polygon b)
@ -70,5 +85,15 @@ namespace MoonTools.Core.Bonk
{ {
return !(a == b); return !(a == b);
} }
public static bool operator ==(Polygon a, Rectangle b)
{
return a.Equals(b);
}
public static bool operator !=(Polygon a, Rectangle b)
{
return !(a == b);
}
} }
} }

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@ -17,7 +17,7 @@ namespace MoonTools.Core.Bonk
public int MaxX { get; } public int MaxX { get; }
public int MaxY { get; } public int MaxY { get; }
private IEnumerable<Position2D> vertices public IEnumerable<Position2D> Vertices
{ {
get get
{ {
@ -38,12 +38,12 @@ namespace MoonTools.Core.Bonk
public Vector2 Support(Vector2 direction, Transform2D transform) public Vector2 Support(Vector2 direction, Transform2D transform)
{ {
return vertices.Select(vertex => Vector2.Transform(vertex, transform.TransformMatrix)).MaxBy(transformed => Vector2.Dot(transformed, direction)).First(); return Vertices.Select(vertex => Vector2.Transform(vertex, transform.TransformMatrix)).MaxBy(transformed => Vector2.Dot(transformed, direction)).First();
} }
public AABB AABB(Transform2D Transform2D) public AABB AABB(Transform2D Transform2D)
{ {
return Bonk.AABB.FromTransformedVertices(vertices, Transform2D); return Bonk.AABB.FromTransformedVertices(Vertices, Transform2D);
} }
public override bool Equals(object obj) public override bool Equals(object obj)
@ -76,7 +76,7 @@ namespace MoonTools.Core.Bonk
hashCode = hashCode * -1521134295 + MinY.GetHashCode(); hashCode = hashCode * -1521134295 + MinY.GetHashCode();
hashCode = hashCode * -1521134295 + MaxX.GetHashCode(); hashCode = hashCode * -1521134295 + MaxX.GetHashCode();
hashCode = hashCode * -1521134295 + MaxY.GetHashCode(); hashCode = hashCode * -1521134295 + MaxY.GetHashCode();
hashCode = hashCode * -1521134295 + EqualityComparer<IEnumerable<Position2D>>.Default.GetHashCode(vertices); hashCode = hashCode * -1521134295 + EqualityComparer<IEnumerable<Position2D>>.Default.GetHashCode(Vertices);
return hashCode; return hashCode;
} }

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@ -253,6 +253,66 @@ namespace Tests
(a != b).Should().BeTrue(); (a != b).Should().BeTrue();
} }
[Test]
public void PolygonRectangleEqual()
{
var a = new Polygon(
new Position2D(1, 1),
new Position2D(1, -1),
new Position2D(-1, -1),
new Position2D(-1, 1)
);
var b = new Rectangle(-1, -1, 1, 1);
a.Should().BeEquivalentTo(b);
}
[Test]
public void PolygonRectangleNotEqual()
{
var a = new Polygon(
new Position2D(2, 1),
new Position2D(1, -1),
new Position2D(-1, -1),
new Position2D(-2, 1)
);
var b = new Rectangle(-1, -1, 1, 1);
a.Should().NotBeEquivalentTo(b);
}
[Test]
public void PolygonRectangleEqualOperator()
{
var a = new Polygon(
new Position2D(1, 1),
new Position2D(1, -1),
new Position2D(-1, -1),
new Position2D(-1, 1)
);
var b = new Rectangle(-1, -1, 1, 1);
(a == b).Should().BeTrue();
}
[Test]
public void PolygonRectangleNotEqualOperator()
{
var a = new Polygon(
new Position2D(2, 1),
new Position2D(1, -1),
new Position2D(-1, -1),
new Position2D(-2, 1)
);
var b = new Rectangle(-1, -1, 1, 1);
(a != b).Should().BeTrue();
}
} }
public class SimplexTests public class SimplexTests