HP Workstation zx6000 HP OpenGL Implementation Guide for HP-UX 11.X (IPF versi - Page 24

overview of OpenGL environment variables Here is a list of environment variables used by HP's implementation of OpenGL. HPOGL_FORCE_VGL This variable can be set to force HP's Virtual GL (VGL) rendering mode using VMD. This differs from HPOGL_FORCE_VMD in that the GLX Visual list and other GLX extension information is not retrieved from the GLX Server extension, but is rather synthesized from standard X Visual information and the capabilities known to exist in VMD. HPOGL_FORCE_VMD This variable forces clients to render through the VMD. This variable can be used as a temporary fix and/or a diagnostic. You should set this variable when a rendering defect in the hardware device driver is suspected. When this variable is set, rendering speed will slow down. If rendering is identical in both hardware and software, then this may indicate a problem in the application code. HPOGL_PROMOTE_INDIRECT_CONTEXTS This variable may be set to force the OpenGL contexts to be direct, if possible, even if the application specifies indirect contexts. This behavior is similar to some previous HP graphics devices. Direct contexts generally provide better performance than indirect ones. HPOGL_LOG_FRAME_RATE This variable may be set to print the frame rate once every second for double-buffered applications. HPOGL_DISABLE_TRANSPARENT_VISUALS This variable may be set to turn off transparent visuals. 1-20 OpenGL implementation guide