// Create a new collision shape in the world.
/// First, this methods checks that the new collision shape does not exist yet in the
/// world. If it already exists, we do not allocate memory for a new one but instead
/// we reuse the existing one. The goal is to only allocate memory for a single
/// collision shape if this one is used for several bodies in the world. To allocate
/// memory for a new collision shape, we use the memory allocator.
CollisionShape* CollisionWorld::createCollisionShape(const CollisionShape& collisionShape) {
// Check if there is already a similar collision shape in the world
std::list<CollisionShape*>::iterator it;
for (it = mCollisionShapes.begin(); it != mCollisionShapes.end(); ++it) {
if (collisionShape == (*(*it))) {
// Increment the number of similar created shapes
(*it)->incrementNbSimilarCreatedShapes();
// A similar collision shape already exists in the world, so we do not
// create a new one but we simply return a pointer to the existing one
return (*it);
}
}
// A similar collision shape does not already exist in the world, so we create a
// new one and add it to the world
void* allocatedMemory = mMemoryAllocator.allocate(collisionShape.getSizeInBytes());
CollisionShape* newCollisionShape = collisionShape.clone(allocatedMemory);
mCollisionShapes.push_back(newCollisionShape);
newCollisionShape->incrementNbSimilarCreatedShapes();
// Return a pointer to the new collision shape
return newCollisionShape;
}
