quadtree: Optimize distance calculation

[sdl-planets] / quadtree.c

diff --git a/quadtree.c b/quadtree.c
index cb4add658e44ed0d25a6968bf6a495c7595ec041..0e9b426a994de984388c1a962f1705e23b2af611 100644 (file)
--- a/quadtree.c
+++ b/quadtree.c
@@ -362,11 +362,11 @@ static struct quadtree *quadtree_find_nearest(struct quadtree *tree,
                nearest = tree;
 
        vector_sub(&nearest->pos, pos, &tmp);
-       distance = vector_abs(&tmp);
+       distance = vector_abs_squared(&tmp);
 
        if (tree != nearest) {
                vector_sub(&tree->pos, pos, &tmp);
-               dist = vector_abs(&tmp);
+               dist = vector_abs_squared(&tmp);
                if (dist < distance) {
                        nearest = tree;
                        distance = dist;
@@ -400,7 +400,7 @@ static struct quadtree *quadtree_find_nearest(struct quadtree *tree,
 
                if (node != nearest) {
                        vector_sub(&node->pos, pos, &tmp);
-                       dist = vector_abs(&tmp);
+                       dist = vector_abs_squared(&tmp);
                        if (dist < distance || !nearest) {
                                nearest = node;
                                distance = dist;
@@ -467,7 +467,7 @@ static struct quadtree *quadtree_find_nearest_noparent(struct quadtree *tree,
                                continue;
 
                        vector_sub(pos, &nearest->pos, &sub);
-                       dist = vector_abs(&sub);
+                       dist = vector_abs_squared(&sub);
                        continue;
                }
                node = quadtree_find_nearest(tree->child[i], pos, corner,
@@ -477,7 +477,7 @@ static struct quadtree *quadtree_find_nearest_noparent(struct quadtree *tree,
                        continue;
 
                vector_sub(pos, &node->pos, &sub);
-               dist2 = vector_abs(&sub);
+               dist2 = vector_abs_squared(&sub);
 
                if (dist2 < dist) {
                        nearest = node;