1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2 <html lang="en"> 3 <head> 4 <meta http-equiv="content-type" content="text/html; charset=utf-8"> 5 <title>Environment Variables</title> 6 <link rel="stylesheet" type="text/css" href="mesa.css"> 7 </head> 8 <body> 9 10 <h1>Environment Variables</h1> 11 12 <p> 13 Normally, no environment variables need to be set. Most of the environment 14 variables used by Mesa/Gallium are for debugging purposes, but they can 15 sometimes be useful for debugging end-user issues. 16 </p> 17 18 19 <h2>LibGL environment variables</h2> 20 21 <ul> 22 <li>LIBGL_DEBUG - If defined debug information will be printed to stderr. 23 If set to 'verbose' additional information will be printed. 24 <li>LIBGL_DRIVERS_PATH - colon-separated list of paths to search for DRI drivers 25 <li>LIBGL_ALWAYS_INDIRECT - forces an indirect rendering context/connection. 26 <li>LIBGL_ALWAYS_SOFTWARE - if set, always use software rendering 27 <li>LIBGL_NO_DRAWARRAYS - if set do not use DrawArrays GLX protocol (for debugging) 28 </ul> 29 30 31 32 <h2>Core Mesa environment variables</h2> 33 34 <ul> 35 <li>MESA_NO_ASM - if set, disables all assembly language optimizations 36 <li>MESA_NO_MMX - if set, disables Intel MMX optimizations 37 <li>MESA_NO_3DNOW - if set, disables AMD 3DNow! optimizations 38 <li>MESA_NO_SSE - if set, disables Intel SSE optimizations 39 <li>MESA_DEBUG - if set, error messages are printed to stderr. For example, 40 if the application generates a GL_INVALID_ENUM error, a corresponding error 41 message indicating where the error occured, and possibly why, will be 42 printed to stderr.<br> 43 If the value of MESA_DEBUG is 'FP' floating point arithmetic errors will 44 generate exceptions. 45 <li>MESA_LOG_FILE - specifies a file name for logging all errors, warnings, 46 etc., rather than stderr 47 <li>MESA_TEX_PROG - if set, implement conventional texture env modes with 48 fragment programs (intended for developers only) 49 <li>MESA_TNL_PROG - if set, implement conventional vertex transformation 50 operations with vertex programs (intended for developers only). 51 Setting this variable automatically sets the MESA_TEX_PROG variable as well. 52 <li>MESA_EXTENSION_OVERRIDE - can be used to enable/disable extensions. 53 A value such as "GL_EXT_foo -GL_EXT_bar" will enable the GL_EXT_foo extension 54 and disable the GL_EXT_bar extension. 55 <li>MESA_EXTENSION_MAX_YEAR - The GL_EXTENSIONS string returned by Mesa is sorted 56 by extension year. 57 If this variable is set to year X, only extensions defined on or before year 58 X will be reported. 59 This is to work-around a bug in some games where the extension string is 60 copied into a fixed-size buffer without truncating. 61 If the extension string is too long, the buffer overrun can cause the game 62 to crash. 63 This is a work-around for that. 64 <li>MESA_GL_VERSION_OVERRIDE - changes the value returned by 65 glGetString(GL_VERSION). Valid values are point-separated version numbers, 66 such as "3.0". Mesa will not really implement all the features of the given 67 version if it's higher than what's normally reported. 68 <li>MESA_GLSL_VERSION_OVERRIDE - changes the value returned by 69 glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as 70 "130". Mesa will not really implement all the features of the given language version 71 if it's higher than what's normally reported. (for developers only) 72 <li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a> 73 </ul> 74 75 76 <h2>Mesa Xlib driver environment variables</h2> 77 78 <p> 79 The following are only applicable to the Mesa Xlib software driver. 80 See the <a href="xlibdriver.html">Xlib software driver page</a> for details. 81 </p> 82 <ul> 83 <li>MESA_RGB_VISUAL - specifies the X visual and depth for RGB mode 84 <li>MESA_CI_VISUAL - specifies the X visual and depth for CI mode 85 <li>MESA_BACK_BUFFER - specifies how to implement the back color buffer, 86 either "pixmap" or "ximage" 87 <li>MESA_GAMMA - gamma correction coefficients for red, green, blue channels 88 <li>MESA_XSYNC - enable synchronous X behavior (for debugging only) 89 <li>MESA_GLX_FORCE_CI - if set, force GLX to treat 8bpp visuals as CI visuals 90 <li>MESA_GLX_FORCE_ALPHA - if set, forces RGB windows to have an alpha channel. 91 <li>MESA_GLX_DEPTH_BITS - specifies default number of bits for depth buffer. 92 <li>MESA_GLX_ALPHA_BITS - specifies default number of bits for alpha channel. 93 </ul> 94 95 96 <h2>i945/i965 driver environment variables (non-Gallium)</h2> 97 98 <ul> 99 <li>INTEL_STRICT_CONFORMANCE - if set to 1, enable sw fallbacks to improve 100 OpenGL conformance. If set to 2, always use software rendering. 101 <li>INTEL_NO_BLIT - if set, disable hardware-accelerated glBitmap, 102 glCopyPixels, glDrawPixels. 103 </ul> 104 105 106 <h2>Radeon driver environment variables (radeon, r200, and r300g)</h2> 107 108 <ul> 109 <li>RADEON_NO_TCL - if set, disable hardware-accelerated Transform/Clip/Lighting. 110 </ul> 111 112 113 <h2>EGL environment variables</h2> 114 115 <p> 116 Mesa EGL supports different sets of environment variables. See the 117 <a href="egl.html">Mesa EGL</a> page for the details. 118 </p> 119 120 121 <h2>Gallium environment variables</h2> 122 123 <ul> 124 <li>GALLIUM_LOG_FILE - specifies a file for logging all errors, warnings, etc. 125 rather than stderr. 126 <li>GALLIUM_PRINT_OPTIONS - if non-zero, print all the Gallium environment 127 variables which are used, and their current values. 128 <li>GALLIUM_NOSSE - if non-zero, do not use SSE runtime code generation for 129 shader execution 130 <li>GALLIUM_NOPPC - if non-zero, do not use PPC runtime code generation for 131 shader execution 132 <li>GALLIUM_DUMP_CPU - if non-zero, print information about the CPU on start-up 133 <li>TGSI_PRINT_SANITY - if set, do extra sanity checking on TGSI shaders and 134 print any errors to stderr. 135 <LI>DRAW_FSE - ??? 136 <LI>DRAW_NO_FSE - ??? 137 <li>DRAW_USE_LLVM - if set to zero, the draw module will not use LLVM to execute 138 shaders, vertex fetch, etc. 139 </ul> 140 141 <h3>Softpipe driver environment variables</h3> 142 <ul> 143 <li>SOFTPIPE_DUMP_FS - if set, the softpipe driver will print fragment shaders 144 to stderr 145 <li>SOFTPIPE_DUMP_GS - if set, the softpipe driver will print geometry shaders 146 to stderr 147 <li>SOFTPIPE_NO_RAST - if set, rasterization is no-op'd. For profiling purposes. 148 <li>SOFTPIPE_USE_LLVM - if set, the softpipe driver will try to use LLVM JIT for 149 vertex shading procesing. 150 </ul> 151 152 153 <h3>LLVMpipe driver environment variables</h3> 154 <ul> 155 <li>LP_NO_RAST - if set LLVMpipe will no-op rasterization 156 <li>LP_DEBUG - a comma-separated list of debug options is acceptec. See the 157 source code for details. 158 <li>LP_PERF - a comma-separated list of options to selectively no-op various 159 parts of the driver. See the source code for details. 160 <li>LP_NUM_THREADS - an integer indicating how many threads to use for rendering. 161 Zero turns of threading completely. The default value is the number of CPU 162 cores present. 163 </ul> 164 165 166 <p> 167 Other Gallium drivers have their own environment variables. These may change 168 frequently so the source code should be consulted for details. 169 </p> 170 171 </body> 172 </html> 173
