Part III. Running Clutter

Emmanuele Bassi


          
        

Environment Variables

Clutter automatically checks environment variables during its initialization. These environment variables are meant as debug tools, overrides for default behaviours or to address known hardware issues:

CLUTTER_TEXT_DIRECTION

Forces the text direction of every Pango layout inside Clutter. Valid values are: ltr or rtl

CLUTTER_SHOW_FPS

Prints out the frames per second achieved by Clutter.

CLUTTER_DEFAULT_FPS

Sets the default framerate.

CLUTTER_DISABLE_MIPMAPPED_TEXT

Disables mipmapping when rendering text.

CLUTTER_FUZZY_PICK

Enables "fuzzy picking".

CLUTTER_DEBUG

Enables debugging modes for Clutter.

COGL_DEBUG

Enables debugging modes for COGL.

On the GLX backend there is also:

CLUTTER_VBLANK

Selects the sync-to-vblank mode to be used. Valid values are: none, dri or glx

Command Line Arguments

Similarly to the environment variables, Clutter also installs command line switches that are parsed during initialization:

--clutter-show-fps

Equivalent of CLUTTER_SHOW_FPS. Prints the current rendering speed in frames per second.

--clutter-default-fps=FPS

Equivalent of CLUTTER_DEFAULT_FPS. Sets the default framerate.

--clutter-text-direction=DIRECTION

Equivalent of CLUTTER_TEXT_DIRECTION. Sets the direction for the text.

--clutter-disable-mipmapped-text

Equivalent of CLUTTER_DISABLE_MIPMAPPED_TEXT. Disables mipmapping when rendering text.

--clutter-use-fuzzy-picking

Equivalent of CLUTTER_FUZZY_PICK. Enables "fuzzy" picking.

--clutter-debug=FLAGS

Equivalent of CLUTTER_DEBUG. Sets FLAGS as the Clutter debugging flags.

--clutter-no-debug=FLAGS

Unsets FLAGS from the Clutter debugging flags.

--cogl-debug=FLAGS

Equivalent of COGL_DEBUG. Sets FLAGS as the COGL debugging flags.

--cogl-no-debug=FLAGS

Unsets FLAGS from the COGL debugging flags.

The X11 backends also have the following command line options:

--display=DISPLAY

Sets the X11 display to use.

--screen=SCREEN

Sets the X11 screen number to use.

--synch

Make X11 calls synchronous.

The GLX backend also has the following command line option:

--vblank=METHOD

Equivalent of CLUTTER_VBLANK. Sets the sync-to-vblank method to be used.