1 <HTML> 2 3 <TITLE>Performance Tips</TITLE> 4 5 <link rel="stylesheet" type="text/css" href="mesa.css"></head> 6 7 <BODY> 8 9 <H1>Performance Tips</H1> 10 11 <p> 12 Performance tips for software rendering: 13 </P> 14 <ol> 15 16 <li> Turn off smooth shading when you don't need it (glShadeModel) 17 <li> Turn off depth buffering when you don't need it. 18 <li> Turn off dithering when not needed. 19 <li> Use double buffering as it's often faster than single buffering 20 <li> Compile in the X Shared Memory extension option if it's supported 21 on your system by adding -DSHM to CFLAGS and -lXext to XLIBS for 22 your system in the Make-config file. 23 <li> Recompile Mesa with more optimization if possible. 24 <li> Try to maximize the amount of drawing done between glBegin/glEnd pairs. 25 <li> Use the MESA_BACK_BUFFER variable to find best performance in double 26 buffered mode. (X users only) 27 <li> Optimized polygon rasterizers are employed when: 28 rendering into back buffer which is an XImage 29 RGB mode, not grayscale, not monochrome 30 depth buffering is GL_LESS, or disabled 31 flat or smooth shading 32 dithered or non-dithered 33 no other rasterization operations enabled (blending, stencil, etc) 34 <li> Optimized line drawing is employed when: 35 rendering into back buffer which is an XImage 36 RGB mode, not grayscale, not monochrome 37 depth buffering is GL_LESS or disabled 38 flat shading 39 dithered or non-dithered 40 no other rasterization operations enabled (blending, stencil, etc) 41 <li> Textured polygons are fastest when: 42 using a 3-component (RGB), 2-D texture 43 minification and magnification filters are GL_NEAREST 44 texture coordinate wrap modes for S and T are GL_REPEAT 45 GL_DECAL environment mode 46 glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST ) 47 depth buffering is GL_LESS or disabled 48 <li> Lighting is fastest when: 49 Two-sided lighting is disabled 50 GL_LIGHT_MODEL_LOCAL_VIEWER is false 51 GL_COLOR_MATERIAL is disabled 52 No spot lights are used (all GL_SPOT_CUTOFFs are 180.0) 53 No local lights are used (all position W's are 0.0) 54 All material and light coefficients are >= zero 55 <li> XFree86 users: if you want to use 24-bit color try starting your 56 X server in 32-bit per pixel mode for better performance. That is, 57 start your X server with 58 startx -- -bpp 32 59 instead of 60 startx -- -bpp 24 61 <li> Try disabling dithering with the MESA_NO_DITHER environment variable. 62 If this env var is defined Mesa will disable dithering and the 63 command glEnable(GL_DITHER) will be ignored. 64 </ol> 65 66 67 </BODY> 68 </HTML> 69
