quadtree: Optimize recalculate_parent_area_stats()

[sdl-planets] / quadtree.c

diff --git a/quadtree.c b/quadtree.c
index 72973c8bba7ae35049f087057790db577719edb6..cb4add658e44ed0d25a6968bf6a495c7595ec041 100644 (file)
--- a/quadtree.c
+++ b/quadtree.c
@@ -213,10 +213,21 @@ static void _recalculate_node_area_stats(struct quadtree *node)
 
 static void recalculate_parent_area_stats(struct quadtree *node)
 {
+       struct vector old_corner[2];
+
        while (node) {
+               memcpy(&old_corner, &node->corner, sizeof(old_corner));
+
                _recalculate_node_area_stats(node);
 
-               node = node->parent;
+               /*
+                * Stop propagating the changes up in the tree if
+                * nothing has changed
+                */
+               if (memcmp(&old_corner, &node->corner, sizeof(old_corner)))
+                       node = node->parent;
+               else
+                       node = NULL;
        }
 }