From: Timo Kokkonen <kaapeli@itanic.dy.fi>
Date: Tue, 7 Dec 2010 18:20:57 +0000 (+0200)
Subject: quadtree.c: Compare vectors, not quadtrees
X-Git-Url: http://git.itanic.dy.fi/?p=sdl-planets;a=commitdiff_plain;h=b909a1a7d710bf473ff33f8c369ae130c6bd7020

quadtree.c: Compare vectors, not quadtrees

Factor out the vector comparison into a separate function. That way it
is more useful if plain vector comparison is needed.

Signed-off-by: Timo Kokkonen <kaapeli@itanic.dy.fi>
---

diff --git a/quadtree.c b/quadtree.c
index 10c4ec8..80b285a 100644
--- a/quadtree.c
+++ b/quadtree.c
@@ -15,6 +15,28 @@ static void trap(void)
 		exit(1);
 }
 
+static int quadtree_compare_coord(const struct vector *a,
+				const struct vector *b)
+{
+	int up, left;
+
+	up = b->y < a->y;
+	left = b->x < a->x;
+
+	if (up && left)
+		return 0;
+	if (up && !left)
+		return 1;
+	if (left)
+		return 2;
+	return 3;
+}
+
+static int quadtree_compare(const struct quadtree *a, const struct quadtree *b)
+{
+	return quadtree_compare_coord(&a->pos, &b->pos);
+}
+
 static void validate_subtree(const struct quadtree *node)
 {
 	int i;
@@ -99,22 +121,6 @@ static void validate_tree(const struct quadtree *node)
 		validate_subtree(quadtree_find_parent(node));
 }
 
-static int quadtree_compare(struct quadtree *a, struct quadtree *b)
-{
-	int up, left;
-
-	up = b->pos.y < a->pos.y;
-	left = b->pos.x < a->pos.x;
-
-	if (up && left)
-		return 0;
-	if (up && !left)
-		return 1;
-	if (left)
-		return 2;
-	return 3;
-}
-
 /**
  * quadtree_add - add a node to a quadtree
  * @parent: parent node