private bool OOBvsCircle(OrientedBoxBody box, CircleBody circle)
{
FixedPointVector3 rotated = MathExt.RotatePoint(circle.position, box.position, 0);
FixedPointVector3 relative = rotated - box.position;
FixedPoint halfW = box.width * FixedPoint.Float05;
FixedPoint halfH = box.height * FixedPoint.Float05;
FixedPointVector3 clamped = new FixedPointVector3(
relative.X.Clamp(-halfW, halfW),
relative.Y.Clamp(-halfH, halfH),
0);
//rotate back
FixedPointVector3 transformedBack = MathExt.RotatePoint(clamped, box.position, 0);
transformedBack += box.position;
return((circle.position - transformedBack).Magnitude <= circle.radius);
}
//lets imagine lib provides FixedPointVector2
private bool CircleVsCircle(CircleBody first, CircleBody second)
{
FixedPoint rSum = (first.radius + second.radius);
return((first.position - second.position).Magnitude <= rSum * rSum);
}