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feat: added CollisionDetectionInformation.ContactPoint

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Syntriax
2026-04-04 00:13:30 +03:00
parent 4c13578125
commit 53b342da46
2 changed files with 64 additions and 8 deletions
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68
Engine.Physics2D/CollisionDetector2D.cs
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@@ -1,3 +1,5 @@
using System.Collections.Generic;
using Engine.Core;
using Engine.Physics2D;
@@ -41,12 +43,13 @@ public class CollisionDetector2D : ICollisionDetector2D
private static bool DetectShapeShapeOneWay(IShapeCollider2D left, IShapeCollider2D right, ref CollisionDetectionInformation collisionInformation)
{
System.Collections.Generic.IReadOnlyList<Vector2D> vertices = left.ShapeWorld.Vertices;
IReadOnlyList<Vector2D> vertices = left.ShapeWorld.Vertices;
int count = vertices.Count;
for (int indexProjection = 0; indexProjection < count; indexProjection++)
{
Vector2D projectionVector = vertices[indexProjection].FromTo(vertices[(indexProjection + 1) % count]).Perpendicular().Normalized;
Vector2D leftEdge = vertices[indexProjection].FromTo(vertices[(indexProjection + 1) % count]);
Vector2D projectionVector = leftEdge.Perpendicular().Normalized;
Projection1D leftProjection = left.ShapeWorld.ToProjection(projectionVector);
Projection1D rightProjection = right.ShapeWorld.ToProjection(projectionVector);
@@ -55,17 +58,61 @@ public class CollisionDetector2D : ICollisionDetector2D
return false;
if (collisionInformation.Detector is null || Math.Abs(collisionInformation.Penetration) > Math.Abs(depth))
collisionInformation = new(left, right, projectionVector, depth);
{
Vector2D contactPoint = FindShapeToShapeContactPoint(left, right, projectionVector);
collisionInformation = new(left, right, contactPoint, projectionVector, depth);
}
}
return true;
}
private static Vector2D FindShapeToShapeContactPoint(IShapeCollider2D left, IShapeCollider2D right, Vector2D contactProjectionVector)
{
IReadOnlyList<Vector2D> leftVertices = left.ShapeWorld.Vertices;
IReadOnlyList<Vector2D> rightVertices = right.ShapeWorld.Vertices;
Line2D leftSupportLine = GetSupportLine(leftVertices, contactProjectionVector);
Line2D rightSupportLine = GetSupportLine(rightVertices, -contactProjectionVector);
if (leftSupportLine.Direction.Dot(rightSupportLine.Direction).Abs() > .99f)
return (leftSupportLine.From + leftSupportLine.To + rightSupportLine.From + rightSupportLine.To) / 4f;
return leftSupportLine.IntersectionPoint(rightSupportLine);
}
private static Line2D GetSupportLine(IReadOnlyList<Vector2D> vertices, Vector2D contactProjectionVector)
{
System.Span<Vector2D> points = stackalloc Vector2D[2];
System.Span<float> distances = stackalloc float[2] { float.MaxValue, float.MaxValue };
for (int i = 0; i < vertices.Count; i++)
{
Vector2D point = vertices[i];
float distance = contactProjectionVector.Dot(point);
if (distance < distances[0])
{
points[1] = points[0];
distances[1] = distances[0];
points[0] = point;
distances[0] = distance;
}
else if (distance < distances[1])
{
points[1] = point;
distances[1] = distance;
}
}
return new(points[0], points[1]);
}
private static bool DetectShapeCircle(IShapeCollider2D shapeCollider, ICircleCollider2D circleCollider, out CollisionDetectionInformation collisionInformation)
{
collisionInformation = default;
System.Collections.Generic.IReadOnlyList<Vector2D> vertices = shapeCollider.ShapeWorld.Vertices;
IReadOnlyList<Vector2D> vertices = shapeCollider.ShapeWorld.Vertices;
int count = vertices.Count;
for (int indexProjection = 0; indexProjection < count; indexProjection++)
@@ -78,8 +125,10 @@ public class CollisionDetector2D : ICollisionDetector2D
if (!shapeProjection.Overlaps(circleProjection, out float depth))
return false;
Vector2D contactPoint = circleCollider.CircleWorld.Center + projectionVector * circleCollider.CircleWorld.Radius;
if (collisionInformation.Detector is null || Math.Abs(collisionInformation.Penetration) > Math.Abs(depth))
collisionInformation = new(shapeCollider, circleCollider, projectionVector, depth);
collisionInformation = new(shapeCollider, circleCollider, contactPoint, projectionVector, depth);
}
{
@@ -91,8 +140,10 @@ public class CollisionDetector2D : ICollisionDetector2D
if (!shapeProjection.Overlaps(circleProjection, out float depth))
return false;
Vector2D contactPoint = circleCollider.CircleWorld.Center + shapeToCircleProjectionVector * circleCollider.CircleWorld.Radius;
if (collisionInformation.Detector is null || Math.Abs(collisionInformation.Penetration) > Math.Abs(depth))
collisionInformation = new(shapeCollider, circleCollider, shapeToCircleProjectionVector, depth);
collisionInformation = new(shapeCollider, circleCollider, contactPoint, shapeToCircleProjectionVector, depth);
}
return true;
@@ -110,7 +161,10 @@ public class CollisionDetector2D : ICollisionDetector2D
bool collision = leftProjection.Overlaps(rightProjection, out float depth);
if (collision)
collisionInformation = new(left, right, leftToRightCenterProjectionVector, depth);
{
Vector2D contactPoint = left.CircleWorld.Center + leftToRightCenterProjectionVector * left.CircleWorld.Radius;
collisionInformation = new(left, right, contactPoint, leftToRightCenterProjectionVector, depth);
}
return collision;
}