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> 12Performance 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