// Polygon versus 2-sided edge.
public static void CollidePolyAndEdge(ref Manifold manifold, PolygonShape polygon, Transform TransformA, EdgeShape edge, Transform TransformB)
{
PolygonShape polygonB = new PolygonShape();
polygonB.SetAsEdge(edge._v1, edge._v2);
CollidePolygons(ref manifold, polygon, TransformA, polygonB, TransformB);
}
// This implements 2-sided edge vs circle collision.
public static void CollideEdgeAndCircle(ref Manifold manifold, EdgeShape edge, Transform transformA, CircleShape circle, Transform transformB)
{
manifold.PointCount = 0;
Vector2 cLocal = Common.Math.MulT(transformA, Common.Math.Mul(transformB, circle._position));
Vector2 normal = edge._normal;
Vector2 v1 = edge._v1;
Vector2 v2 = edge._v2;
float radius = edge._radius + circle._radius;
// Barycentric coordinates
float u1 = Vector2.Dot(cLocal - v1, v2 - v1);
float u2 = Vector2.Dot(cLocal - v2, v1 - v2);
if (u1 <= 0.0f)
{
// Behind v1
if ((cLocal- v1).sqrMagnitude > radius * radius)
{
return;
}
manifold.PointCount = 1;
manifold.Type = ManifoldType.FaceA;
manifold.LocalPlaneNormal = cLocal - v1;
manifold.LocalPlaneNormal.Normalize();
manifold.LocalPoint = v1;
manifold.Points[0].LocalPoint = circle._position;
manifold.Points[0].ID.Key = 0;
}
else if (u2 <= 0.0f)
{
// Ahead of v2
if ((cLocal- v2).sqrMagnitude > radius * radius)
{
return;
}
manifold.PointCount = 1;
manifold.Type = ManifoldType.FaceA;
manifold.LocalPlaneNormal = cLocal - v2;
manifold.LocalPlaneNormal.Normalize();
manifold.LocalPoint = v2;
manifold.Points[0].LocalPoint = circle._position;
manifold.Points[0].ID.Key = 0;
}
else
{
float separation = Vector2.Dot(cLocal - v1, normal);
if (separation < -radius || radius < separation)
{
return;
}
manifold.PointCount = 1;
manifold.Type = ManifoldType.FaceA;
manifold.LocalPlaneNormal = separation < 0.0f ? -normal : normal;
manifold.LocalPoint = 0.5f * (v1 + v2);
manifold.Points[0].LocalPoint = circle._position;
manifold.Points[0].ID.Key = 0;
}
}
public void SetPrevEdge(EdgeShape edge, Vector2 cornerDir, bool convex)
{
_prevEdge = edge;
_cornerDir1 = cornerDir;
_cornerConvex1 = convex;
}
public void SetNextEdge(EdgeShape edge, Vector2 cornerDir, bool convex)
{
_nextEdge = edge;
_cornerDir2 = cornerDir;
_cornerConvex2 = convex;
}
public void SetNextEdge(EdgeShape edge, Vec2 cornerDir, bool convex)
{
_nextEdge = edge;
_cornerDir2 = cornerDir;
_cornerConvex2 = convex;
}
public void SetPrevEdge(EdgeShape edge, Vec2 cornerDir, bool convex)
{
_prevEdge = edge;
_cornerDir1 = cornerDir;
_cornerConvex1 = convex;
}
public void Create(BroadPhase broadPhase, Body body, XForm xf, FixtureDef def)
{
UserData = def.UserData;
Friction = def.Friction;
Restitution = def.Restitution;
Density = def.Density;
_body = body;
_next = null;
Filter = def.Filter;
_isSensor = def.IsSensor;
_type = def.Type;
// Allocate and initialize the child shape.
switch (_type)
{
case ShapeType.CircleShape:
{
CircleShape circle = new CircleShape();
CircleDef circleDef = (CircleDef)def;
circle._position = circleDef.LocalPosition;
circle._radius = circleDef.Radius;
_shape = circle;
}
break;
case ShapeType.PolygonShape:
{
PolygonShape polygon = new PolygonShape();
PolygonDef polygonDef = (PolygonDef)def;
polygon.Set(polygonDef.Vertices, polygonDef.VertexCount);
_shape = polygon;
}
break;
case ShapeType.EdgeShape:
{
EdgeShape edge = new EdgeShape();
EdgeDef edgeDef = (EdgeDef)def;
edge.Set(edgeDef.Vertex1, edgeDef.Vertex2);
_shape = edge;
}
break;
default:
Box2DXDebug.Assert(false);
break;
}
// Create proxy in the broad-phase.
AABB aabb;
_shape.ComputeAABB(out aabb, xf);
bool inRange = broadPhase.InRange(aabb);
// You are creating a shape outside the world box.
Box2DXDebug.Assert(inRange);
if (inRange)
{
_proxyId = broadPhase.CreateProxy(aabb, this);
}
else
{
_proxyId = PairManager.NullProxy;
}
}
// Polygon versus 2-sided edge.
public static void CollidePolyAndEdge(ref Manifold manifold, PolygonShape polygon, Transform TransformA, EdgeShape edge, Transform TransformB)
{
PolygonShape polygonB = new PolygonShape();
polygonB.SetAsEdge(edge._v1, edge._v2);
CollidePolygons(ref manifold, polygon, TransformA, polygonB, TransformB);
}
// This implements 2-sided edge vs circle collision.
public static void CollideEdgeAndCircle(ref Manifold manifold, EdgeShape edge, Transform transformA, CircleShape circle, Transform transformB)
{
manifold.PointCount = 0;
Vector2 cLocal = Common.Math.MulT(transformA, Common.Math.Mul(transformB, circle._position));
Vector2 normal = edge._normal;
Vector2 v1 = edge._v1;
Vector2 v2 = edge._v2;
float radius = edge._radius + circle._radius;
// Barycentric coordinates
float u1 = Vector2.Dot(cLocal - v1, v2 - v1);
float u2 = Vector2.Dot(cLocal - v2, v1 - v2);
if (u1 <= 0.0f)
{
// Behind v1
if ((cLocal - v1).sqrMagnitude > radius * radius)
{
return;
}
manifold.PointCount = 1;
manifold.Type = ManifoldType.FaceA;
manifold.LocalPlaneNormal = cLocal - v1;
manifold.LocalPlaneNormal.Normalize();
manifold.LocalPoint = v1;
manifold.Points[0].LocalPoint = circle._position;
manifold.Points[0].ID.Key = 0;
}
else if (u2 <= 0.0f)
{
// Ahead of v2
if ((cLocal - v2).sqrMagnitude > radius * radius)
{
return;
}
manifold.PointCount = 1;
manifold.Type = ManifoldType.FaceA;
manifold.LocalPlaneNormal = cLocal - v2;
manifold.LocalPlaneNormal.Normalize();
manifold.LocalPoint = v2;
manifold.Points[0].LocalPoint = circle._position;
manifold.Points[0].ID.Key = 0;
}
else
{
float separation = Vector2.Dot(cLocal - v1, normal);
if (separation < -radius || radius < separation)
{
return;
}
manifold.PointCount = 1;
manifold.Type = ManifoldType.FaceA;
manifold.LocalPlaneNormal = separation < 0.0f ? -normal : normal;
manifold.LocalPoint = 0.5f * (v1 + v2);
manifold.Points[0].LocalPoint = circle._position;
manifold.Points[0].ID.Key = 0;
}
}
