private Collision2D(PhysicsBody2D A, PhysicsBody2D B)
{
// For ease of computing around static dynamic collisions I have decided the static body should always be BodyA
if (A.flagBodyType.HasFlag(PhysicsEngine.BodyType.STATIC) || A.flagBodyType.HasFlag(PhysicsEngine.BodyType.KINEMATIC) || B.flagBodyType.HasFlag(PhysicsEngine.BodyType.STATIC) || B.flagBodyType.HasFlag(PhysicsEngine.BodyType.KINEMATIC))
{
if (A.flagBodyType.HasFlag(PhysicsEngine.BodyType.STATIC) || A.flagBodyType.HasFlag(PhysicsEngine.BodyType.KINEMATIC))
{
BodyA = A;
BodyB = B;
}
else
{
BodyA = B;
BodyB = A;
}
}
else
{
BodyA = A;
BodyB = B;
}
type = PhysicsEngine.CollisionType.NONE;
}
/// <summary>
/// Evaluates whether the collision is occuring or not
/// </summary>
/// <returns>Whether a collision is occuring or not</returns>
public bool Evaluate()
{
bool test = BodyA.shape.OverlapTest(BodyB.shape, BodyA.transform, BodyB.transform);
// If the test returns true, collision is occuring
// If this type is start and test is true, collision is continuing
if (type == PhysicsEngine.CollisionType.START && test)
{
type = PhysicsEngine.CollisionType.STAY;
//BodyA.Broadcast(this, "OnCollision2DStay");
//BodyB.Broadcast(this, "OnCollision2DStay");
BodyA.PhysicsBody2DCallStay(this);
BodyB.PhysicsBody2DCallStay(this);
}
// If this type is none and test is true, collision is starting
if (type == PhysicsEngine.CollisionType.NONE && test)
{
type = PhysicsEngine.CollisionType.START;
//BodyA.Broadcast(this, "OnCollision2DStart");
//BodyB.Broadcast(this, "OnCollision2DStart");
BodyA.PhysicsBody2DCallStart(this);
BodyB.PhysicsBody2DCallStart(this);
}
// If this type is stop and test is false, collision is none
if (type == PhysicsEngine.CollisionType.STOP && !test)
{
type = PhysicsEngine.CollisionType.NONE;
}
// If this type is start or stay and test is false, collision is ending
if ((type == PhysicsEngine.CollisionType.START || type == PhysicsEngine.CollisionType.STAY) && !test)
{
type = PhysicsEngine.CollisionType.STOP;
//BodyA.Broadcast(this, "OnCollision2DStop");
//BodyB.Broadcast(this, "OnCollision2DStop");
BodyA.PhysicsBody2DCallStop(this);
BodyB.PhysicsBody2DCallStop(this);
}
// If this type is stop and test is true, collision is starting, again
if (type == PhysicsEngine.CollisionType.STOP && test)
{
type = PhysicsEngine.CollisionType.START;
//BodyA.Broadcast(this, "OnCollision2DStart");
//BodyB.Broadcast(this, "OnCollision2DStart");
BodyA.PhysicsBody2DCallStart(this);
BodyB.PhysicsBody2DCallStart(this);
}
if (test)
{
foreach (Collision2D.OnCollision callback in BodyA.collisionCallbacks)
{
callback.Invoke(this);
}
foreach (Collision2D.OnCollision callback in BodyB.collisionCallbacks)
{
callback.Invoke(this);
}
}
return(test);
}