Event emitted for each physics collision pair.
Normal components are flattened (normalX/normalY) rather than nested in a Vector2D to avoid a per-event allocation in the physics hot path.
normalX
normalY
Vector2D
Penetration depth (positive)
Unit normal X, pointing from A toward B
Unit normal Y, pointing from A toward B
Event emitted for each physics collision pair.
Normal components are flattened (
normalX/normalY) rather than nested in aVector2Dto avoid a per-event allocation in the physics hot path.