public static bool detectCircleRectangle(scTransform circleTransform, scCircleShape circle, scTransform rectangleTransform, scRectangleShape rectangle)
{
var transformedRectangleVertices = new List<Vector2>();
foreach (var vertex in rectangle.vertices)
{
transformedRectangleVertices.Add(scTransformUtils.applyTransform(rectangleTransform, vertex));
}
var axes = new List<Vector2>();
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[0], transformedRectangleVertices[1]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[1], transformedRectangleVertices[2]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[2], transformedRectangleVertices[3]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[3], transformedRectangleVertices[0]));
var transformedCircleCenter = scTransformUtils.applyTransform(circleTransform, circle.localPosition);
//get nearest edge vertex to circle center
var distancesToVertices = new List<Vector2>();
distancesToVertices.Add(transformedRectangleVertices[0] - transformedCircleCenter);
distancesToVertices.Add(transformedRectangleVertices[1] - transformedCircleCenter);
distancesToVertices.Add(transformedRectangleVertices[2] - transformedCircleCenter);
distancesToVertices.Add(transformedRectangleVertices[3] - transformedCircleCenter);
var circleAxis = distancesToVertices[0];
foreach (var distance in distancesToVertices)
{
if (distance.Length() < circleAxis.Length())
{
circleAxis = distance;
}
}
circleAxis.Normalize();
axes.Add(circleAxis);
foreach (var axis in axes)
{
var lineSegmentRectangleA = scCollisionHelpers.projectCircleOnAxis(transformedCircleCenter, circle.radius, axis);
var lineSegmentRectangleB = scCollisionHelpers.projectShapeOnAxis(transformedRectangleVertices, axis);
if (!scCollisionHelpers.overlapsOnSameAxis(lineSegmentRectangleA, lineSegmentRectangleB))
{
return false;
}
}
return true;
}
public static scRectangleShape fromLocalPositionAndHalfExtents(Vector2 localPosition, Vector2 halfExtents)
{
var rectangleShape = new scRectangleShape();
rectangleShape.vertices[0].X = localPosition.X - halfExtents.X;
rectangleShape.vertices[0].Y = localPosition.Y - halfExtents.Y;
rectangleShape.vertices[1].X = localPosition.X + halfExtents.X;
rectangleShape.vertices[1].Y = localPosition.Y - halfExtents.Y;
rectangleShape.vertices[2].X = localPosition.X + halfExtents.X;
rectangleShape.vertices[2].Y = localPosition.Y + halfExtents.Y;
rectangleShape.vertices[3].X = localPosition.X - halfExtents.X;
rectangleShape.vertices[3].Y = localPosition.Y + halfExtents.Y;
return rectangleShape;
}
public static bool detectRectangleRectangle(scTransform aTransform, scRectangleShape aShape, scTransform bTransform, scRectangleShape bShape)
{
var transformedRectangleVerticesA = new List<Vector2>();
var transformedRectangleVerticesB = new List<Vector2>();
foreach (var vertex in aShape.vertices)
{
transformedRectangleVerticesA.Add(scTransformUtils.applyTransform(aTransform, vertex));
}
foreach (var vertex in bShape.vertices)
{
transformedRectangleVerticesB.Add(scTransformUtils.applyTransform(bTransform, vertex));
}
var axes = new List<Vector2>();
// add axes of aShape
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesA[0], transformedRectangleVerticesA[1]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesA[1], transformedRectangleVerticesA[2]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesA[2], transformedRectangleVerticesA[3]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesA[3], transformedRectangleVerticesA[0]));
// add axes of bShape
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesB[0], transformedRectangleVerticesB[1]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesB[1], transformedRectangleVerticesB[2]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesB[2], transformedRectangleVerticesB[3]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVerticesB[3], transformedRectangleVerticesB[0]));
foreach (var axis in axes)
{
var lineSegmentRectangleA = scCollisionHelpers.projectShapeOnAxis(transformedRectangleVerticesA, axis);
var lineSegmentRectangleB = scCollisionHelpers.projectShapeOnAxis(transformedRectangleVerticesB, axis);
if (!scCollisionHelpers.overlapsOnSameAxis(lineSegmentRectangleA, lineSegmentRectangleB))
{
return false;
}
}
return true;
}
public static bool detectRectangleEdge(scTransform rectangleTransform, scRectangleShape rectangle, scTransform edgeTransform, scEdgeShape edge)
{
var transformedRectangleVertices = new List<Vector2>();
foreach (var vertex in rectangle.vertices)
{
transformedRectangleVertices.Add(scTransformUtils.applyTransform(rectangleTransform, vertex));
}
var edgeStart = scTransformUtils.applyTransform(edgeTransform, edge.start);
var edgeEnd = scTransformUtils.applyTransform(edgeTransform, edge.end);
var transformedEdgeVertices = new List<Vector2>();
transformedEdgeVertices.Add(edgeStart);
transformedEdgeVertices.Add(edgeEnd);
var axes = new List<Vector2>();
axes.Add(scCollisionHelpers.getNormal(edgeStart, edgeEnd));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[0], transformedRectangleVertices[1]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[1], transformedRectangleVertices[2]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[2], transformedRectangleVertices[3]));
axes.Add(scCollisionHelpers.getNormal(transformedRectangleVertices[3], transformedRectangleVertices[0]));
foreach (var axis in axes)
{
var lineSegmentRectangle = scCollisionHelpers.projectShapeOnAxis(transformedRectangleVertices, axis);
var lineSegmentEdge = scCollisionHelpers.projectShapeOnAxis(transformedEdgeVertices, axis);
if (!scCollisionHelpers.overlapsOnSameAxis(lineSegmentRectangle, lineSegmentEdge))
{
return false;
}
}
return true;
}
