void QuadTree::BuildRecursive(QuadTreeNode * node, List<MeshInstanceNode*> & meshNodes)
{
cache.Reset();
//meshNodes
AABBox3 bbox = node->GetBoundingBox();
AABBox3 childBoxes[4];
Vector3 halfSize = (bbox.max - bbox.min) / 2.0f;
childBoxes[0] = AABBox3(Vector3(bbox.min.x, bbox.min.y, bbox.min.z), Vector3(bbox.min.x + halfSize.x, bbox.min.y + halfSize.y, bbox.max.z));
childBoxes[1] = AABBox3(Vector3(bbox.min.x + halfSize.x, bbox.min.y, bbox.min.z), Vector3(bbox.max.x, bbox.min.y + halfSize.y, bbox.max.z));
childBoxes[2] = AABBox3(Vector3(bbox.min.x, bbox.min.y + halfSize.y, bbox.min.z), Vector3(bbox.min.x + halfSize.x, bbox.max.y, bbox.max.z));
childBoxes[3] = AABBox3(Vector3(bbox.min.x + halfSize.x, bbox.min.y + halfSize.y, bbox.min.z), Vector3(bbox.max.x, bbox.max.y, bbox.max.z));
AABBox3 realChildBox[4];
int32 childCount[4] = {0, 0, 0, 0};
List<MeshInstanceNode*> childLists[4];
for (List<MeshInstanceNode*>::iterator it = meshNodes.begin(); it != meshNodes.end();)
{
MeshInstanceNode * mesh = *it;
bool nodeIn = false;
for (int k = 0; k < 4; ++k)
{
const AABBox3 & bbox = mesh->GetWTMaximumBoundingBox();
if (childBoxes[k].IsInside(bbox))
{
childCount[k]++;
childLists[k].push_back(mesh);
realChildBox[k].AddAABBox(bbox);
nodeIn = true;
break;
}
}
if (nodeIn)
{
it = meshNodes.erase(it);
}else
{
it++;
}
}
//for (each new node where number of nodes inside is not 0 build recursively)
for (int k = 0; k < 4; ++k)
{
if (childCount[k] > 0)
{
nodeCount++;
node->children[k] = cache.New();
node->children[k]->SetBoundingBox(realChildBox[k]);
BuildRecursive(node->children[k], childLists[k]);
}
}
// all objects that are not in childs remains in this node
for (List<MeshInstanceNode*>::iterator it = meshNodes.begin(); it != meshNodes.end(); ++it)
{
node->objectsInside.push_back(SafeRetain(*it));
}
}
