+/**
+ * Test if we pixel buffers are available for a particular X screen.
+ * Input: dpy - the X display
+ * screen - screen number
+ * Return: 0 = pixel buffers not available.
+ * 1 = pixel buffers are available via GLX 1.3.
+ * 2 = pixel buffers are available via GLX_SGIX_fbconfig/pbuffer.
+ */
+int
+QueryPbuffers(Display *dpy, int screen)
+{
+ int ret;