computeAABB method
Given a transform, compute the associated axis aligned bounding box for a child shape.
Implementation
@override
void computeAABB(AABB aabb, Transform transform, int childIndex) {
final tq = transform.q;
final tp = transform.p;
final px = tq.cos * position.x - tq.sin * position.y + tp.x;
final py = tq.sin * position.x + tq.cos * position.y + tp.y;
aabb.lowerBound.x = px - radius;
aabb.lowerBound.y = py - radius;
aabb.upperBound.x = px + radius;
aabb.upperBound.y = py + radius;
}