Environment Variables - HP Workstation zx2000 Implementation Manual

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.
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