From d758359791fb5a8a6c083b96161170f512a7fdb9 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Sun, 13 Oct 2013 21:29:48 -0300
Subject: [PATCH] poly2d/p2d_hsort.c (p2d_hier_free): make freeing of polygons
 optional

---
 poly2d/f2d_tri.c   |  2 +-
 poly2d/p2d_area.c  |  6 +++---
 poly2d/p2d_hsort.c | 11 ++++++-----
 poly2d/p2d_hsort.h |  8 +++++---
 4 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/poly2d/f2d_tri.c b/poly2d/f2d_tri.c
index bab50f3..418ce88 100644
--- a/poly2d/f2d_tri.c
+++ b/poly2d/f2d_tri.c
@@ -37,6 +37,6 @@ struct f2d *f2d_tri(const struct p2d *p)
 
 	t = p2d_hsort(p);
 	recurse_area(t, &last);
-	p2d_hier_free(t);
+	p2d_hier_free(t, 0);
 	return res;
 }
diff --git a/poly2d/p2d_area.c b/poly2d/p2d_area.c
index bc45a66..b0ef6b1 100644
--- a/poly2d/p2d_area.c
+++ b/poly2d/p2d_area.c
@@ -1,8 +1,8 @@
 /*
  * p2d_area.c - Fill a set of nested polygons
  *
- * Written 2012 by Werner Almesberger
- * Copyright 2012 Werner Almesberger
+ * Written 2012, 2013 by Werner Almesberger
+ * Copyright 2012, 2013 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -39,6 +39,6 @@ struct p2d *p2d_area(const struct p2d *p, double first, double next)
 
 	t = p2d_hsort(p);
 	recurse_area(t, first, next, &last);
-	p2d_hier_free(t);
+	p2d_hier_free(t, 1);
 	return res;
 }
diff --git a/poly2d/p2d_hsort.c b/poly2d/p2d_hsort.c
index 07aa958..2570211 100644
--- a/poly2d/p2d_hsort.c
+++ b/poly2d/p2d_hsort.c
@@ -1,8 +1,8 @@
 /*
  * p2d_hsort.c - Hierarchical polygon sort
  *
- * Written 2012 by Werner Almesberger
- * Copyright 2012 Werner Almesberger
+ * Written 2012, 2013 by Werner Almesberger
+ * Copyright 2012, 2013 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -92,16 +92,17 @@ struct p2d_hier *p2d_hsort(const struct p2d *p)
 }
 
 
-void p2d_hier_free(struct p2d_hier *t)
+void p2d_hier_free(struct p2d_hier *t, bool free_poly)
 {
 	struct p2d_hier *next;
 	struct p2d *p;
 
 	while (t) {
-		p2d_hier_free(t->holes);
+		p2d_hier_free(t->holes, free_poly);
 		p = &t->p;
 		next = p2d_to_hier(p->next);
-		p2d_free(p);
+		if (free_poly)
+			p2d_free(p);
 		t = next;
 	}
 }
diff --git a/poly2d/p2d_hsort.h b/poly2d/p2d_hsort.h
index e789656..8f9b37c 100644
--- a/poly2d/p2d_hsort.h
+++ b/poly2d/p2d_hsort.h
@@ -1,8 +1,8 @@
 /*
  * p2d_hsort.h - Hierarchical polygon sort
  *
- * Written 2012 by Werner Almesberger
- * Copyright 2012 Werner Almesberger
+ * Written 2012, 2013 by Werner Almesberger
+ * Copyright 2012, 2013 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -14,6 +14,8 @@
 #ifndef P2D_HSORT_H
 #define P2D_HSORT_H
 
+#include <stdbool.h>
+
 #include "poly2d.h"
 
 
@@ -27,6 +29,6 @@ struct p2d_hier {
 
 
 struct p2d_hier *p2d_hsort(const struct p2d *p);
-void p2d_hier_free(struct p2d_hier *t);
+void p2d_hier_free(struct p2d_hier *t, bool free_poly);
 
 #endif /* !P2D_HSORT_H */