From: Dan Winship <danw@src.gnome.org>
Date: Tue, 13 Jan 2009 20:49:31 +0000 (+0000)
Subject: Make sure the animation always starts from the first frame, even if the
X-Git-Tag: archive/raspbian/50.5-1+rpi1~1^2~1013^2^2~11495
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=ca724920a3daa3bf83a298cf49a60bdc7265f4c7;p=gnome-shell.git

Make sure the animation always starts from the first frame, even if the
system is really busy and ClutterTimeline doesn't get a chance to call
us until it thinks several frames have passed

svn path=/trunk/; revision=147
---

diff --git a/js/ui/main.js b/js/ui/main.js
index af535e314..b4e1fab62 100644
--- a/js/ui/main.js
+++ b/js/ui/main.js
@@ -64,8 +64,18 @@ ClutterFrameTicker.prototype = {
         // So by dynamically adjusting the value of FRAME_RATE we can trick
         // it into dealing with dropped frames.
 
-        let delta = frame - this._frame;
-        if (delta == 0)
+        // If there is a lot of setup to start the animation, then
+        // first frame number we get from clutter might be a long ways
+        // into the animation (or the animation might even be done).
+        // That looks bad, so we always start one frame into the
+        // animation then only do frame dropping from there.
+        let delta;
+        if (this._frame == 0)
+            delta = 1;
+        else
+            delta = frame - this._frame;
+
+        if (delta == 0) // protect against divide-by-0 if we get a frame twice
             this.FRAME_RATE = this.TARGET_FRAME_RATE;
         else
             this.FRAME_RATE = this.TARGET_FRAME_RATE / delta;