[gtk+/gestures: 130/173] rotate: Ensure delta is betwee n [0..2π]

[Carlos Garnacho <carlosg src gnome org>]

commit cf0d7ad4cfb24d79f9619a8ed66fdccb418f6831
Author: Carlos Garnacho <carlosg gnome org>
Date:   Tue May 6 11:43:31 2014 +0200

    rotate: Ensure delta is between [0..2π]

 gtk/gtkgesturerotate.c |    9 ++++++---
 1 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkgesturerotate.c b/gtk/gtkgesturerotate.c
index 9521298..ec8b12a 100644
--- a/gtk/gtkgesturerotate.c
+++ b/gtk/gtkgesturerotate.c
@@ -110,15 +110,18 @@ static gboolean
 _gtk_gesture_rotate_check_emit (GtkGestureRotate *gesture)
 {
   GtkGestureRotatePrivate *priv;
-  gdouble angle;
+  gdouble angle, delta;
 
   if (!_gtk_gesture_rotate_get_angle (gesture, &angle))
     return FALSE;
 
   priv = gtk_gesture_rotate_get_instance_private (gesture);
+  delta = angle - priv->initial_angle;
+
+  if (delta < 0)
+    delta += 2 * G_PI;
 
-  g_signal_emit (gesture, signals[ANGLE_CHANGED], 0,
-                 angle, angle - priv->initial_angle);
+  g_signal_emit (gesture, signals[ANGLE_CHANGED], 0, angle, delta);
   return TRUE;
 }