glfw/glfw — pull request #184 by andrewcorrigan (2013-12-04 03:21:27+00:00)
Title: disable Xkb, workaround ChooseFBConfigSGIX failure

These commits enable the use of GLFW applications running across TurboVNC+VirtualGL, whereas GLFW previously failed entirely. Two issues are addressed, one of which was previously reported as https://github.com/glfw/glfw/issues/130

1. Xkb is made optional. The Xkb extension is missing on a platform I have to support (RHEL6 running over TurboVNC and VirtualGL). The deprecated function XKeycodeToKeysym is used as a fallback for when Xkb is not available. Since this function is deprecated, to avoid compiler warnings, the call is only enabled at compile-time by disabling GLFW_USE_XKB.
2. The call to ChooseFBConfigSGIX often fails, and now, rather than stopping with an error, an attempt is made to call glXGetFBConfigs as a fallback.