bool Level::isCollisions(Entity * e)
{
if(e->getBoundingBox() == NULL)
return false;
// Note : optimizable
const AxisAlignedBB & box = *(e->getBoundingBox());
std::list<Collision> collisions;
getCollisions(collisions, box, e);
return !collisions.empty();
}
std::vector<Collision> OcTree::getCollisions(Node* n, std::vector<GameObject*> objects){
std::vector<Collision> collisions;
//create a vector that is a copy of the objects provided combined with the objects in this node
std::vector<GameObject*> colObjects;
colObjects = n->objects;
std::vector<GameObject*>::iterator it_end = colObjects.end();
colObjects.insert(colObjects.end(), objects.begin(), objects.end());
std::vector<GameObject*>::iterator ii, jj;
GameObject* a;
GameObject* b;
//do an O(n^2) collision check between all objects in colObjects
//TODO figure out how to properly do these nested loops without going out of bounds
for (ii = n->objects.begin(); ii != n->objects.end(); ++ii){
a = *ii;
//TODO only have dynamic objects check against other objects, but prevent double checks...
//Possible solution, if objects come from 'above' don't have them check each other.
//Compare n->objects against colObjects, and match the iterators.
for (jj = ii + 1; jj != n->objects.end(); ++jj){
b = *jj;
if(a == b || (!a->changedPosition && !b->changedPosition)) //don't compare objects against itself or if both objects haven't moved
continue;
if(a->getCollider()->collidesWith(b->getCollider(), a->cachedPosition, b->cachedPosition )){
Collision col;
col.a = a;
col.b = b;
collisions.push_back(col);
}
collisionChecks++;
}
for (jj = objects.begin(); jj != objects.end(); ++jj){
b = *jj;
if(a == b || (!a->changedPosition && !b->changedPosition)) //don't compare objects against itself or if both objects haven't moved
continue;
if(a->getCollider()->collidesWith(b->getCollider(), a->cachedPosition, b->cachedPosition )){
Collision col;
col.a = a;
col.b = b;
collisions.push_back(col);
}
collisionChecks++;
}
}
int kk;
std::vector<GameObject*> list;
for (kk = 0; kk < 8; kk++){
if(n->children[kk] == NULL)
continue;
for (ii = colObjects.begin(); ii != colObjects.end(); ++ii){
if (Bounding::intersects(&((*ii)->getCollider()->boundingBox), &(n->children[kk]->bounds))){
list.push_back(*ii);
}
}
std::vector<Collision> result = getCollisions(n->children[kk], list);
collisions.insert(collisions.end(), result.begin(), result.end());
list.clear();
}
return collisions;
}
std::vector<Collision> OcTree::getCollisions(std::vector<GameObject*> objects){
return getCollisions(root, objects);
}
std::vector<Collision> OcTree::getCollisions(){
return getCollisions(root, std::vector<GameObject*>());
}
