simple collision detection

[mirat]

I want only to know if two btCollisionObjects are in collision, no information about contact points is needed. I check if broadphase pair exists for given objects, and then get number of manifolds. Does existing of one or more manifolds means colliding of two objects? Can manifold exist when it doesn't contain any contact points (I mean if checking of manifolds count is not enought)?

Code: Select all

bool check_collision (const btCollisionObject * body0, const btCollisionObject * body1) const
{
	btCollisionWorld * world = get_bt_world();       // my function returning active btCollisionWorld
	const btBroadphaseProxy * prox0 = body0->getBroadphaseHandle();
	const btBroadphaseProxy * prox1 = body1->getBroadphaseHandle();
	btBroadphasePair * pair = world->getBroadphase()->getOverlappingPairCache()->findPair(prox0, prox1);

	if (pair)
	{
		btManifoldArray manifoldArray;

		if (pair->m_algorithm) pair->m_algorithm->getAllContactManifolds(manifoldArray);
		if (manifoldArray.size() > 0)
		{
			return true;
		}
	}

	return false;
}

[mirat]

Answering myself: no, not enough. Final code below, I hope it will be useful to somebody

Code: Select all

bool check_collision (const btCollisionObject * body0, const btCollisionObject * body1) const
{
   btCollisionWorld * world = get_bt_world();       // my function returning active btCollisionWorld
   const btBroadphaseProxy * prox0 = body0->getBroadphaseHandle();
   const btBroadphaseProxy * prox1 = body1->getBroadphaseHandle();
   btBroadphasePair * pair = world->getBroadphase()->getOverlappingPairCache()->findPair(prox0, prox1);

   if (pair)
   {
      btManifoldArray manifoldArray;

      if (pair->m_algorithm) pair->m_algorithm->getAllContactManifolds(manifoldArray);
      for (unsigned int i = 0, s = manifoldArray.size(); i < s; ++i )
      {
         if ( manifoldArray[i]->getNumContacts() > 0 ) return true;
      }  
   }

   return false;
}