From 13e6ace75baf7fae9aef12f6adec8fc2f06a09d0 Mon Sep 17 00:00:00 2001
From: Timo Kokkonen <kaapeli@itanic.dy.fi>
Date: Sat, 30 Oct 2010 21:56:59 +0300
Subject: [PATCH] Move quadtree comparison code inside quadtree.c

The .compare function can also be removed now from the quadtree_ops
structure.

Signed-off-by: Timo Kokkonen <kaapeli@itanic.dy.fi>
---
 planet.c   | 20 --------------------
 quadtree.c | 29 ++++++++++++++++++-----------
 quadtree.h |  6 ------
 3 files changed, 18 insertions(+), 37 deletions(-)

diff --git a/planet.c b/planet.c
index 39f8c35..24b2d21 100644
--- a/planet.c
+++ b/planet.c
@@ -374,25 +374,6 @@ void print_planet(const struct planet *p)
 	       p->tree.pos.x, p->tree.pos.y, p->speed.x, p->speed.y, p->mass, p->radius);
 }
 
-int planet_spatial_compare(struct quadtree *ta, struct quadtree *tb)
-{
-	struct planet *a, *b;
-	int up, left;
-	a = tree_to_planet(ta);
-	b = tree_to_planet(tb);
-
-	up = b->tree.pos.y < a->tree.pos.y;
-	left = b->tree.pos.x < a->tree.pos.x;
-
-	if (up && left)
-		return 0;
-	if (up && !left)
-		return 1;
-	if (left)
-		return 2;
-	return 3;
-}
-
 int planet_search_rectangular(struct quadtree *node,
 			      struct quadtree_iterator *itr)
 {
@@ -460,7 +441,6 @@ static void planet_recalculate_stats(struct quadtree *node)
 }
 
 struct quadtree_ops planet_ops = {
-	.compare = planet_spatial_compare,
 	.recalculate_stats = planet_recalculate_stats,
 };
 
diff --git a/quadtree.c b/quadtree.c
index 61a2699..10c4ec8 100644
--- a/quadtree.c
+++ b/quadtree.c
@@ -99,22 +99,29 @@ 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
  * @new: the new node to be added
- * @compare: pointer to a comparison function
  *
  * Add a node to a quadtree. The tree is kept in order, the new node
- * is placed in the end of appropriate branch. The compare function is
- * used to compare the new node against a branch in the tree. The
- * comparison function must have following return value depending on
- * the position of node a compared to the position of node b:
- *
- * 0: upper left
- * 1: upper right
- * 2: lower left
- * 3: lower right
+ * is placed in the end of appropriate branch.
  *
  * The case of nodes sharing identical coordinates is not taken into
  * account at all.
@@ -129,7 +136,7 @@ struct quadtree *quadtree_add(struct quadtree *parent, struct quadtree *new,
 
 	validate_tree(parent);
 
-	ret = ops->compare(parent, new);
+	ret = quadtree_compare(parent, new);
 
 	if (ret < 0 || ret >= 4) {
 		printf("Invalid comparison result of %d\n", ret);
diff --git a/quadtree.h b/quadtree.h
index 87f3b8c..619a675 100644
--- a/quadtree.h
+++ b/quadtree.h
@@ -17,12 +17,6 @@ struct quadtree {
 };
 
 struct quadtree_ops {
-	/*
-	 * Comparison function that is needed to find out the correct
-	 * location for a node in the tree
-	 */
-	int (*compare)(struct quadtree *a, struct quadtree *b);
-
 	/*
 	 * Calculates required statistical information for a node
 	 */
-- 
2.45.0