Index: src/video/quartz/SDL_QuartzGL.m
===================================================================
RCS file: /home/sdlweb/libsdl.org/cvs/SDL12/src/video/quartz/SDL_QuartzGL.m,v
retrieving revision 1.10
diff -u -r1.10 SDL_QuartzGL.m
--- src/video/quartz/SDL_QuartzGL.m	6 Dec 2005 14:36:39 -0000	1.10
+++ src/video/quartz/SDL_QuartzGL.m	30 Jan 2006 18:15:34 -0000
@@ -56,6 +56,7 @@
     NSOpenGLPixelFormat *fmt;
     int i = 0;
     int colorBits = bpp;
+    long value;
 
     /* if a GL library hasn't been loaded at this point, load the default. */
     if (!this->gl_config.driver_loaded) {
@@ -132,6 +133,14 @@
         return 0;
     }
 
+    /* Synchronize QZ_GL_SwapBuffers() to vertical retrace.
+     * (Apple's documentation is not completely clear about what this setting
+     * exactly does, IMHO - for a detailed explanation see
+     * http://lists.apple.com/archives/mac-opengl/2006/Jan/msg00080.html )
+     */
+    value = 1;
+    [ gl_context setValues: &value forParameter: NSOpenGLCPSwapInterval ];
+
     /*
      * Wisdom from Apple engineer in reference to UT2003's OpenGL performance:
      *  "You are blowing a couple of the internal OpenGL function caches. This