+typedef struct bh_iter bh_iter;
+struct bh_iter{
+ struct {
+ i32 id, depth;
+ }
+ stack[64];
+
+ enum bh_query_type{
+ k_bh_query_box,
+ k_bh_query_ray
+ }
+ query;
+
+ union{
+ struct{
+ boxf box;
+ }
+ box;
+
+ struct{
+ v3f co, inv_dir;
+ f32 max_dist;
+ }
+ ray;
+ };
+
+ i32 depth, i;
+};
+
+VG_STATIC void bh_iter_init_box( i32 root, bh_iter *it, boxf box ){
+ it->query = k_bh_query_box;
+ it->stack[0].id = root;
+ it->stack[0].depth = 0;
+ it->depth = 0;
+ it->i = 0;
+
+ box_copy( box, it->box.box );
+}
+
+VG_STATIC void bh_iter_init_ray( i32 root, bh_iter *it, v3f co,
+ v3f dir, f32 max_dist ){
+ it->query = k_bh_query_ray;
+ it->stack[0].id = root;
+ it->stack[0].depth = 0;
+ it->depth = 0;
+ it->i = 0;
+
+ v3_div( (v3f){1.0f,1.0f,1.0f}, dir, it->ray.inv_dir );
+ v3_copy( co, it->ray.co );
+ it->ray.max_dist = max_dist;
+}
+
+VG_STATIC i32 bh_next( bh_tree *bh, bh_iter *it, i32 *em ){
+ while( it->depth >= 0 ){
+ bh_node *inode = &bh->nodes[ it->stack[it->depth].id ];
+
+ /* Only process overlapping nodes */
+ i32 q = 0;
+
+ if( it->query == k_bh_query_box )
+ q = box_overlap( inode->bbx, it->box.box );
+ else
+ q = ray_aabb1( inode->bbx, it->ray.co,
+ it->ray.inv_dir, it->ray.max_dist );
+
+ if( !q ){
+ it->depth --;
+ continue;
+ }
+
+ if( inode->count ){
+ if( it->i < inode->count ){
+ *em = inode->start+it->i;
+ it->i ++;
+ return 1;
+ }
+ else{
+ it->depth --;
+ it->i = 0;
+ }
+ }
+ else{
+ if( it->depth+1 >= vg_list_size(it->stack) ){
+ vg_error( "Maximum stack reached!\n" );
+ return 0;
+ }
+
+ it->stack[it->depth ].id = inode->il;
+ it->stack[it->depth+1].id = inode->ir;
+ it->depth ++;
+ it->i = 0;
+ }
+ }
+
+ return 0;
+}
+
+VG_STATIC int bh_closest_point( bh_tree *bh, v3f pos,
+ v3f closest, float max_dist )