From db518c8736f09215fbb31dfb1f6b2464c0c31332 Mon Sep 17 00:00:00 2001
From: Chris Lord <chris@openedhand.com>
Date: Tue, 10 Jun 2008 10:05:12 +0000
Subject: [PATCH]         * clutter/cogl/common/cogl-primitives.c:
 (_cogl_path_arc):         Draw as expected when end angle is lower than start
 angle (i.e. do not         swap the angles). This aligns with cairo
 behaviour.

---
 ChangeLog                             |  6 +++++
 clutter/cogl/common/cogl-primitives.c | 34 ++++++++++++++++++++-------
 2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f6836719c..bb070995f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2008-06-10  Chris Lord  <chris@openedhand.com>
+
+	* clutter/cogl/common/cogl-primitives.c: (_cogl_path_arc):
+	Draw as expected when end angle is lower than start angle (i.e. do not
+	swap the angles). This aligns with cairo behaviour.
+
 2008-06-10  Tommi Komulainen  <tommi.komulainen@iki.fi>
 
 	Bug#959 - Multiple minor improvements
diff --git a/clutter/cogl/common/cogl-primitives.c b/clutter/cogl/common/cogl-primitives.c
index 2018c4444..43d78b85f 100644
--- a/clutter/cogl/common/cogl-primitives.c
+++ b/clutter/cogl/common/cogl-primitives.c
@@ -207,7 +207,6 @@ _cogl_path_arc (ClutterFixed center_x,
                 guint        move_first)
 {
   ClutterAngle a     = 0x0;
-  ClutterAngle temp  = 0x0;
   ClutterFixed cosa  = 0x0;
   ClutterFixed sina  = 0x0;
   ClutterFixed px    = 0x0;
@@ -221,16 +220,10 @@ _cogl_path_arc (ClutterFixed center_x,
   if (angle_step < 0x0)
     angle_step = -angle_step;
   
-  if (angle_2 < angle_1)
-    {
-      temp = angle_1;
-      angle_1 = angle_2;
-      angle_2 = temp;
-    }
-  
   /* Walk the arc by given step */
   
-  for (a = angle_1; a < angle_2; a += angle_step)
+  a = angle_1;
+  while (a != angle_2)
     {
       cosa = clutter_cosi (a);
       sina = clutter_sini (a);
@@ -242,7 +235,30 @@ _cogl_path_arc (ClutterFixed center_x,
 	cogl_path_move_to (px, py);
       else
 	cogl_path_line_to (px, py);
+      
+      if (G_LIKELY (angle_2 > angle_1))
+        {
+          a += angle_step;
+          if (a > angle_2)
+            a = angle_2;
+        }
+      else
+        {
+          a -= angle_step;
+          if (a < angle_2)
+            a = angle_2;
+        }
     }
+
+  /* Make sure the final point is drawn */
+  
+  cosa = clutter_cosi (angle_2);
+  sina = clutter_sini (angle_2);
+
+  px = center_x + CFX_MUL (cosa, radius_x);
+  py = center_y + CFX_MUL (sina, radius_y);
+
+  cogl_path_line_to (px, py);
 }
 
 void