1Application Issues 2================== 3 4This page documents known issues with some OpenGL applications. 5 6Topogun 7------- 8 9`Topogun <http://www.topogun.com/>`__ for Linux (version 2, at least) 10creates a GLX visual without requesting a depth buffer. This causes bad 11rendering if the OpenGL driver happens to choose a visual without a 12depth buffer. 13 14Mesa 9.1.2 and later (will) support a DRI configuration option to work 15around this issue. Using the 16`driconf <https://dri.freedesktop.org/wiki/DriConf>`__ tool, set the 17"Create all visuals with a depth buffer" option before running Topogun. 18Then, all GLX visuals will be created with a depth buffer. 19 20Old OpenGL games 21---------------- 22 23Some old OpenGL games (approx. ten years or older) may crash during 24start-up because of an extension string buffer-overflow problem. 25 26The problem is a modern OpenGL driver will return a very long string for 27the ``glGetString(GL_EXTENSIONS)`` query and if the application naively 28copies the string into a fixed-size buffer it can overflow the buffer 29and crash the application. 30 31The work-around is to set the ``MESA_EXTENSION_MAX_YEAR`` environment 32variable to the approximate release year of the game. This will cause 33the ``glGetString(GL_EXTENSIONS)`` query to only report extensions older 34than the given year. 35 36For example, if the game was released in 2001, do 37 38.. code-block:: console 39 40 export MESA_EXTENSION_MAX_YEAR=2001 41 42before running the game. 43 44Viewperf 45-------- 46 47See the :doc:`Viewperf issues <viewperf>` page for a detailed list of 48Viewperf issues. 49