[cairo] Antialiasing not working with glitz

[Charles Tuckey]

I am using the latest cairo (0.1.22), glitz (0.1.0) and libpixman 
(0.1.1) libraries to display an ellipse on a Linux OS. I noticed that 
pixman displays the ellipse with antialiasing but that the opengl 
version does not have antialiasing. My example program is based on the 
cairogears demo program.

We have tested this on three different graphics cards running with the 
latest available drivers:
   GeForce 2 MX
   GeForce 2 FX
   ATI Radeon 9800

Does anyone have an idea why this might be? I have screenshots if they 
would help.

Here is the code I use to create the glitz surface:

   GtkWidget *window = SWT.Shell.handle;   // pseudo code
   gtk_widget_set_double_buffered (window, FALSE);

   GdkDrawable *drawable;
   gint x_offset, y_offset;
   gdk_window_get_internal_paint_info (window->window,
				      &drawable, &x_offset, &y_offset);
   Display *dpy = GDK_WINDOW_XDISPLAY(drawable);

   glitz_format_t *format =
     glitz_glx_find_standard_format (dpy, DefaultScreen (dpy),
                                     GLITZ_FORMAT_OPTION_ONSCREEN_MASK,
                                     GLITZ_STANDARD_RGB24);

   Window win = GDK_WINDOW_XID(window->window);
   glitz_surface_t *glitz_surface =
       glitz_glx_surface_create_for_window (dpy, DefaultScreen (dpy),
                                            format, win);


thanks,
charlie