Allow forcing off the texture_for_pixmap extension by environment
variable, since it is apparently buggy on old Intel cards with
certain driver versions
Based on patch from RainCT (Siegfried Gevatter)
svn path=/trunk/; revision=92
"""Starts gnome-shell. Returns a subprocess.Popen object"""
use_tfp = self.use_tfp
+
+ # Allow disabling usage of the EXT_texture_for_pixmap extension.
+ # FIXME: Move this to ClutterGlxPixmap like
+ # CLUTTER_PIXMAP_TEXTURE_RECTANGLE=disable.
+ if 'GNOME_SHELL_DISABLE_DISABLE_TFP' in os.environ and
+ os.environ['GNOME_SHELL_DISABLE_DISABLE_TFP'] != '':
+ use_tfp = False
+
if use_tfp:
# Check if GLX supports GL_ARB_texture_non_power_of_two; currently clutter
# can only use GLX_EXT_texture_for_pixmap if we have that extension.