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+<div class="header">
+ <h1>The Mesa 3D Graphics Library</h1>
+</div>
+
+<iframe src="contents.html"></iframe>
+<div class="content">
+
<h1>Environment Variables</h1>
<p>
<li>LIBGL_ALWAYS_INDIRECT - forces an indirect rendering context/connection.
<li>LIBGL_ALWAYS_SOFTWARE - if set, always use software rendering
<li>LIBGL_NO_DRAWARRAYS - if set do not use DrawArrays GLX protocol (for debugging)
+<li>LIBGL_SHOW_FPS - print framerate to stdout based on the number of glXSwapBuffers
+ calls per second.
+<li>LIBGL_DRI3_DISABLE - disable DRI3 if set (the value does not matter)
</ul>
<li>MESA_NO_SSE - if set, disables Intel SSE optimizations
<li>MESA_DEBUG - if set, error messages are printed to stderr. For example,
if the application generates a GL_INVALID_ENUM error, a corresponding error
- message indicating where the error occured, and possibly why, will be
+ message indicating where the error occurred, and possibly why, will be
printed to stderr.<br>
If the value of MESA_DEBUG is 'FP' floating point arithmetic errors will
generate exceptions.
+<li>MESA_LOG_FILE - specifies a file name for logging all errors, warnings,
+etc., rather than stderr
<li>MESA_TEX_PROG - if set, implement conventional texture env modes with
fragment programs (intended for developers only)
<li>MESA_TNL_PROG - if set, implement conventional vertex transformation
to crash.
This is a work-around for that.
<li>MESA_GL_VERSION_OVERRIDE - changes the value returned by
-glGetString(GL_VERSION). Valid values are point-separated version numbers,
-such as "3.0". Mesa will not really implement all the features of the given
-version if it's higher than what's normally reported.
+glGetString(GL_VERSION) and possibly the GL API type.
+<ul>
+<li> The format should be MAJOR.MINOR[FC]
+<li> FC is an optional suffix that indicates a forward compatible context.
+This is only valid for versions >= 3.0.
+<li> GL versions < 3.0 are set to a compatibility (non-Core) profile
+<li> GL versions = 3.0, see below
+<li> GL versions > 3.0 are set to a Core profile
+<li> Examples: 2.1, 3.0, 3.0FC, 3.1, 3.1FC
+<ul>
+<li> 2.1 - select a compatibility (non-Core) profile with GL version 2.1
+<li> 3.0 - select a compatibility (non-Core) profile with GL version 3.0
+<li> 3.0FC - select a Core+Forward Compatible profile with GL version 3.0
+<li> 3.1 - select a Core profile with GL version 3.1
+<li> 3.1FC - select a Core+Forward Compatible profile with GL version 3.1
+</ul>
+<li> Mesa may not really implement all the features of the given version.
+(for developers only)
+</ul>
<li>MESA_GLSL_VERSION_OVERRIDE - changes the value returned by
glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as
"130". Mesa will not really implement all the features of the given language version
<h2>i945/i965 driver environment variables (non-Gallium)</h2>
<ul>
-<li>INTEL_STRICT_CONFORMANCE - if set to 1, enable sw fallbacks to improve
- OpenGL conformance. If set to 2, always use software rendering.
-<li>INTEL_NO_BLIT - if set, disable hardware-accelerated glBitmap,
- glCopyPixels, glDrawPixels.
+<li>INTEL_NO_HW - if set to 1, prevents batches from being submitted to the hardware.
+ This is useful for debugging hangs, etc.</li>
+<li>INTEL_DEBUG - a comma-separated list of named flags, which do various things:
+<ul>
+ <li>tex - emit messages about textures.</li>
+ <li>state - emit messages about state flag tracking</li>
+ <li>blit - emit messages about blit operations</li>
+ <li>miptree - emit messages about miptrees</li>
+ <li>perf - emit messages about performance issues</li>
+ <li>perfmon - emit messages about AMD_performance_monitor</li>
+ <li>bat - emit batch information</li>
+ <li>pix - emit messages about pixel operations</li>
+ <li>buf - emit messages about buffer objects</li>
+ <li>reg - emit messages about regions</li>
+ <li>fbo - emit messages about framebuffers</li>
+ <li>fs - dump shader assembly for fragment shaders</li>
+ <li>gs - dump shader assembly for geometry shaders</li>
+ <li>sync - emit messages about synchronization</li>
+ <li>prim - emit messages about drawing primitives</li>
+ <li>vert - emit messages about vertex assembly</li>
+ <li>dri - emit messages about the DRI interface</li>
+ <li>sf - emit messages about the strips & fans unit (for old gens, includes the SF program)</li>
+ <li>stats - enable statistics counters. you probably actually want perfmon or intel_gpu_top instead.</li>
+ <li>urb - emit messages about URB setup</li>
+ <li>vs - dump shader assembly for vertex shaders</li>
+ <li>clip - emit messages about the clip unit (for old gens, includes the CLIP program)</li>
+ <li>aub - dump batches into an AUB trace for use with simulation tools</li>
+ <li>shader_time - record how much GPU time is spent in each shader</li>
+ <li>no16 - suppress generation of 16-wide fragment shaders. useful for debugging broken shaders</li>
+ <li>blorp - emit messages about the blorp operations (blits & clears)</li>
+ <li>nodualobj - suppress generation of dual-object geometry shader code</li>
+ <li>optimizer - dump shader assembly to files at each optimization pass and iteration that make progress</li>
+</ul>
</ul>
<h2>Gallium environment variables</h2>
<ul>
+<li>GALLIUM_HUD - draws various information on the screen, like framerate,
+ cpu load, driver statistics, performance counters, etc.
+ Set GALLIUM_HUD=help and run e.g. glxgears for more info.
+<li>GALLIUM_HUD_PERIOD - sets the hud update rate in seconds (float). Use zero
+ to update every frame. The default period is 1/2 second.
+<li>GALLIUM_HUD_VISIBLE - control default visibility, defaults to true.
+<li>GALLIUM_HUD_TOGGLE_SIGNAL - toggle visibility via user specified signal.
+ Especially useful to toggle hud at specific points of application and
+ disable for unencumbered viewing the rest of the time. For example, set
+ GALLIUM_HUD_VISIBLE to false and GALLIUM_HUD_SIGNAL_TOGGLE to 10 (SIGUSR1).
+ Use kill -10 <pid> to toggle the hud as desired.
+<li>GALLIUM_LOG_FILE - specifies a file for logging all errors, warnings, etc.
+ rather than stderr.
<li>GALLIUM_PRINT_OPTIONS - if non-zero, print all the Gallium environment
variables which are used, and their current values.
-<li>GALLIUM_NOSSE - if non-zero, do not use SSE runtime code generation for
- shader execution
-<li>GALLIUM_NOPPC - if non-zero, do not use PPC runtime code generation for
- shader execution
<li>GALLIUM_DUMP_CPU - if non-zero, print information about the CPU on start-up
<li>TGSI_PRINT_SANITY - if set, do extra sanity checking on TGSI shaders and
print any errors to stderr.
<LI>DRAW_NO_FSE - ???
<li>DRAW_USE_LLVM - if set to zero, the draw module will not use LLVM to execute
shaders, vertex fetch, etc.
+<li>ST_DEBUG - controls debug output from the Mesa/Gallium state tracker.
+Setting to "tgsi", for example, will print all the TGSI shaders.
+See src/mesa/state_tracker/st_debug.c for other options.
</ul>
<h3>Softpipe driver environment variables</h3>
to stderr
<li>SOFTPIPE_NO_RAST - if set, rasterization is no-op'd. For profiling purposes.
<li>SOFTPIPE_USE_LLVM - if set, the softpipe driver will try to use LLVM JIT for
- vertex shading procesing.
+ vertex shading processing.
</ul>
<h3>LLVMpipe driver environment variables</h3>
<ul>
<li>LP_NO_RAST - if set LLVMpipe will no-op rasterization
-<li>LP_DEBUG - a comma-separated list of debug options is acceptec. See the
+<li>LP_DEBUG - a comma-separated list of debug options is accepted. See the
source code for details.
<li>LP_PERF - a comma-separated list of options to selectively no-op various
parts of the driver. See the source code for details.
cores present.
</ul>
+<h3>VMware SVGA driver environment variables</h3>
+<ul>
+<li>SVGA_FORCE_SWTNL - force use of software vertex transformation
+<li>SVGA_NO_SWTNL - don't allow software vertex transformation fallbacks
+(will often result in incorrect rendering).
+<li>SVGA_DEBUG - for dumping shaders, constant buffers, etc. See the code
+for details.
+<li>See the driver code for other, lesser-used variables.
+</ul>
+
+
+<h3>VA-API state tracker environment variables</h3>
+<ul>
+<li>VAAPI_MPEG4_ENABLED - enable MPEG4 for VA-API, disabled by default.
+</ul>
+
<p>
Other Gallium drivers have their own environment variables. These may change
frequently so the source code should be consulted for details.
</p>
+</div>
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