godot/core/math/bvh_refit.inc
2021-05-05 15:02:01 +02:00

142 lines
3.3 KiB
C++

void _debug_node_verify_bound(uint32_t p_node_id) {
TNode &node = _nodes[p_node_id];
BVHABB_CLASS abb_before = node.aabb;
node_update_aabb(node);
BVHABB_CLASS abb_after = node.aabb;
CRASH_COND(abb_before != abb_after);
}
void node_update_aabb(TNode &tnode) {
tnode.aabb.set_to_max_opposite_extents();
tnode.height = 0;
if (!tnode.is_leaf()) {
for (int n = 0; n < tnode.num_children; n++) {
uint32_t child_node_id = tnode.children[n];
// merge with child aabb
const TNode &tchild = _nodes[child_node_id];
tnode.aabb.merge(tchild.aabb);
// do heights at the same time
if (tchild.height > tnode.height) {
tnode.height = tchild.height;
}
}
// the height of a non leaf is always 1 bigger than the biggest child
tnode.height++;
#ifdef BVH_CHECKS
if (!tnode.num_children) {
// the 'blank' aabb will screw up parent aabbs
WARN_PRINT("BVH_Tree::TNode no children, AABB is undefined");
}
#endif
} else {
// leaf
const TLeaf &leaf = _node_get_leaf(tnode);
for (int n = 0; n < leaf.num_items; n++) {
tnode.aabb.merge(leaf.get_aabb(n));
}
// now the leaf items are unexpanded, we expand only in the node AABB
tnode.aabb.expand(_node_expansion);
#ifdef BVH_CHECKS
if (!leaf.num_items) {
// the 'blank' aabb will screw up parent aabbs
WARN_PRINT("BVH_Tree::TLeaf no items, AABB is undefined");
}
#endif
}
}
void refit_all(int p_tree_id) {
refit_downward(_root_node_id[p_tree_id]);
}
void refit_upward(uint32_t p_node_id) {
while (p_node_id != BVHCommon::INVALID) {
TNode &tnode = _nodes[p_node_id];
node_update_aabb(tnode);
p_node_id = tnode.parent_id;
}
}
void refit_upward_and_balance(uint32_t p_node_id) {
while (p_node_id != BVHCommon::INVALID) {
uint32_t before = p_node_id;
p_node_id = _logic_balance(p_node_id);
if (before != p_node_id) {
VERBOSE_PRINT("REBALANCED!");
}
TNode &tnode = _nodes[p_node_id];
// update overall aabb from the children
node_update_aabb(tnode);
p_node_id = tnode.parent_id;
}
}
void refit_downward(uint32_t p_node_id) {
TNode &tnode = _nodes[p_node_id];
// do children first
if (!tnode.is_leaf()) {
for (int n = 0; n < tnode.num_children; n++) {
refit_downward(tnode.children[n]);
}
}
node_update_aabb(tnode);
}
// go down to the leaves, then refit upward
void refit_branch(uint32_t p_node_id) {
// our function parameters to keep on a stack
struct RefitParams {
uint32_t node_id;
};
// most of the iterative functionality is contained in this helper class
BVH_IterativeInfo<RefitParams> ii;
// alloca must allocate the stack from this function, it cannot be allocated in the
// helper class
ii.stack = (RefitParams *)alloca(ii.get_alloca_stacksize());
// seed the stack
ii.get_first()->node_id = p_node_id;
RefitParams rp;
// while there are still more nodes on the stack
while (ii.pop(rp)) {
TNode &tnode = _nodes[rp.node_id];
// do children first
if (!tnode.is_leaf()) {
for (int n = 0; n < tnode.num_children; n++) {
uint32_t child_id = tnode.children[n];
// add to the stack
RefitParams *child = ii.request();
child->node_id = child_id;
}
} else {
// leaf .. only refit upward if dirty
TLeaf &leaf = _node_get_leaf(tnode);
if (leaf.is_dirty()) {
leaf.set_dirty(false);
refit_upward(p_node_id);
}
}
} // while more nodes to pop
}