1<HTML> 2 3<TITLE>Environment Variables</TITLE> 4 5<link rel="stylesheet" type="text/css" href="mesa.css"></head> 6 7<BODY> 8 9<H1>Environment Variables</H1> 10 11<p> 12Mesa supports the following environment variables: 13</p> 14<ul> 15<li>MESA_NO_ASM - if set, disables all assembly language optimizations 16<li>MESA_NO_MMX - if set, disables Intel MMX optimizations 17<li>MESA_NO_3DNOW - if set, disables AMD 3DNow! optimizations 18<li>MESA_NO_SSE - if set, disables Intel SSE optimizations 19<li>MESA_DEBUG - if set, error messages are printed to stderr. 20If the value of MESA_DEBUG is "FP" floating point arithmetic errors will 21generate exceptions. 22<li>MESA_NO_DITHER - if set, disables dithering, overriding glEnable(GL_DITHER) 23<li>MESA_TEX_PROG - if set, implement conventional texture env modes with 24fragment programs (intended for developers only) 25<li>MESA_TNL_PROG - if set, implement conventional vertex transformation 26operations with vertex programs (intended for developers only). 27Setting this variable automatically sets the MESA_TEX_PROG variable as well. 28<li>MESA_EXTENSION_OVERRIDE - can be used to enable/disable extensions. 29A value such as "GL_EXT_foo -GL_EXT_bar" will enable the GL_EXT_foo extension 30and disable the GL_EXT_bar extension. 31<li>MESA_GLSL - <a href="shading.html#envvars">shading language options</a> 32</ul> 33 34<p> 35The following are only applicable to the Xlib software driver. 36See the <A HREF="xlibdriver.html">Xlib software driver page</A> for details. 37</p> 38<ul> 39<li>MESA_RGB_VISUAL - specifies the X visual and depth for RGB mode 40<li>MESA_CI_VISUAL - specifies the X visual and depth for CI mode 41<li>MESA_BACK_BUFFER - specifies how to implement the back color buffer, 42 either "pixmap" or "ximage" 43<li>MESA_GAMMA - gamma correction coefficients for red, green, blue channels 44<li>MESA_XSYNC - enable synchronous X behavior (for debugging only) 45<li>MESA_GLX_FORCE_CI - if set, force GLX to treat 8bpp visuals as CI visuals 46<li>MESA_GLX_FX - set to either "fullscreen" for full-screen rendering, 47 "window" to render into a window, or "disable" to disable the Glide driver. 48<li>MESA_GLX_FORCE_ALPHA - if set, forces RGB windows to have an alpha channel. 49<li>MESA_GLX_DEPTH_BITS - specifies default number of bits for depth buffer. 50<li>MESA_GLX_ALPHA_BITS - specifies default number of bits for alpha channel. 51</ul> 52 53 54<p> 55These environment variables are for the Intel i945/i965 drivers: 56</p> 57<ul> 58<li>INTEL_STRICT_CONFORMANCE - if set to 1, enable sw fallbacks to improve 59 OpenGL conformance. If set to 2, always use software rendering. 60<li>INTEL_NO_BLIT - if set, disable hardware-accelerated glBitmap, 61 glCopyPixels, glDrawPixels. 62</ul> 63 64 65<p> 66These environment variables are for the Radeon R300 driver: 67</p> 68<ul> 69<li>R300_NO_TCL - if set, disable hardware-accelerated Transform/Clip/Lighting. 70</ul> 71 72<p> 73Mesa EGL supports different sets of environment variables. See the 74<a href="egl.html">Mesa EGL</a> page for the details. 75</p> 76 77</BODY> 78</HTML> 79