private Rectangle CalculateBoundingBox(IHasTransform parent, IPerPixelCollisionComponent collisionComponent)
{
var transform =
Matrix.CreateTranslation(-new Vector3(collisionComponent.RotationAnchor ?? Vector2.Zero, 0)) *
Matrix.CreateFromQuaternion(parent.FinalTransform.AbsoluteRotation) *
//Matrix.CreateTranslation(new Vector3(collisionComponent.RotationAnchor ?? Vector2.Zero, 0)) *
Matrix.CreateTranslation(parent.FinalTransform.AbsolutePosition);
var width = collisionComponent.GetPixelWidth();
var height = collisionComponent.GetPixelHeight();
var tl = Vector2.Transform(Vector2.Zero, transform);
var tr = Vector2.Transform(new Vector2(width, 0), transform);
var bl = Vector2.Transform(new Vector2(0, height), transform);
var br = Vector2.Transform(new Vector2(width, height), transform);
var minX = Math.Min(Math.Min(tl.X, tr.X), Math.Min(bl.X, br.X));
var minY = Math.Min(Math.Min(tl.Y, tr.Y), Math.Min(bl.Y, br.Y));
var maxX = Math.Max(Math.Max(tl.X, tr.X), Math.Max(bl.X, br.X));
var maxY = Math.Max(Math.Max(tl.Y, tr.Y), Math.Max(bl.Y, br.Y));
return(new Rectangle(
(int)Math.Floor(minX),
(int)Math.Floor(minY),
(int)Math.Ceiling(maxX) - (int)Math.Floor(minX),
(int)Math.Ceiling(maxY) - (int)Math.Floor(minY)));
}
private bool IntersectPixels(
IHasTransform aParent,
IPerPixelCollisionComponent a,
IHasTransform bParent,
IPerPixelCollisionComponent b)
{
var transformA =
Matrix.CreateTranslation(-new Vector3(a.RotationAnchor ?? Vector2.Zero, 0)) *
Matrix.CreateFromQuaternion(aParent.FinalTransform.AbsoluteRotation) *
//Matrix.CreateTranslation(new Vector3(a.RotationAnchor ?? Vector2.Zero, 0)) *
Matrix.CreateTranslation(aParent.FinalTransform.AbsolutePosition);
var transformB =
Matrix.CreateTranslation(-new Vector3(b.RotationAnchor ?? Vector2.Zero, 0)) *
Matrix.CreateFromQuaternion(bParent.FinalTransform.AbsoluteRotation) *
//Matrix.CreateTranslation(new Vector3(b.RotationAnchor ?? Vector2.Zero, 0)) *
Matrix.CreateTranslation(bParent.FinalTransform.AbsolutePosition);
var widthA = a.GetPixelWidth();
var heightA = a.GetPixelHeight();
var widthB = b.GetPixelWidth();
var heightB = b.GetPixelHeight();
var dataA = a.GetPixelData();
var dataB = b.GetPixelData();
var transformAToB = transformA * Matrix.Invert(transformB);
var stepX = Vector2.TransformNormal(Vector2.UnitX, transformAToB);
var stepY = Vector2.TransformNormal(Vector2.UnitY, transformAToB);
var yPosInB = Vector2.Transform(Vector2.Zero, transformAToB);
for (var yA = 0; yA < heightA; yA++)
{
var posInB = yPosInB;
for (var xA = 0; xA < widthA; xA++)
{
var xB = (int)Math.Round(posInB.X);
var yB = (int)Math.Round(posInB.Y);
if (0 <= xB && xB < widthB &&
0 <= yB && yB < heightB)
{
var colorA = dataA[xA + yA * widthA];
var colorB = dataB[xB + yB * widthB];
if (colorA.A != 0 && colorB.A != 0)
{
return(true);
}
}
posInB += stepX;
}
yPosInB += stepY;
}
return(false);
}