| Brian Paul | 0b27ace | 2003-03-08 17:38:57 +0000 | [diff] [blame] | 1 | <HTML> |
| 2 | |
| 3 | <TITLE>Performance Tips</TITLE> |
| 4 | |
| 5 | <BODY text="#000000" bgcolor="#55bbff" link="#111188"> |
| 6 | |
| 7 | <H1>Performance Tips</H1> |
| 8 | |
| 9 | <p> |
| 10 | Performance tips for software rendering: |
| 11 | </P> |
| 12 | <ol> |
| 13 | |
| 14 | <li> Turn off smooth shading when you don't need it (glShadeModel) |
| 15 | <li> Turn off depth buffering when you don't need it. |
| 16 | <li> Turn off dithering when not needed. |
| 17 | <li> Use double buffering as it's often faster than single buffering |
| 18 | <li> Compile in the X Shared Memory extension option if it's supported |
| 19 | on your system by adding -DSHM to CFLAGS and -lXext to XLIBS for |
| 20 | your system in the Make-config file. |
| 21 | <li> Recompile Mesa with more optimization if possible. |
| 22 | <li> Try to maximize the amount of drawing done between glBegin/glEnd pairs. |
| 23 | <li> Use the MESA_BACK_BUFFER variable to find best performance in double |
| 24 | buffered mode. (X users only) |
| 25 | <li> Optimized polygon rasterizers are employed when: |
| 26 | rendering into back buffer which is an XImage |
| 27 | RGB mode, not grayscale, not monochrome |
| 28 | depth buffering is GL_LESS, or disabled |
| 29 | flat or smooth shading |
| 30 | dithered or non-dithered |
| 31 | no other rasterization operations enabled (blending, stencil, etc) |
| 32 | <li> Optimized line drawing is employed when: |
| 33 | rendering into back buffer which is an XImage |
| 34 | RGB mode, not grayscale, not monochrome |
| 35 | depth buffering is GL_LESS or disabled |
| 36 | flat shading |
| 37 | dithered or non-dithered |
| 38 | no other rasterization operations enabled (blending, stencil, etc) |
| 39 | <li> Textured polygons are fastest when: |
| 40 | using a 3-component (RGB), 2-D texture |
| 41 | minification and magnification filters are GL_NEAREST |
| 42 | texture coordinate wrap modes for S and T are GL_REPEAT |
| 43 | GL_DECAL environment mode |
| 44 | glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST ) |
| 45 | depth buffering is GL_LESS or disabled |
| 46 | <li> Lighting is fastest when: |
| 47 | Two-sided lighting is disabled |
| 48 | GL_LIGHT_MODEL_LOCAL_VIEWER is false |
| 49 | GL_COLOR_MATERIAL is disabled |
| 50 | No spot lights are used (all GL_SPOT_CUTOFFs are 180.0) |
| 51 | No local lights are used (all position W's are 0.0) |
| 52 | All material and light coefficients are >= zero |
| 53 | <li> XFree86 users: if you want to use 24-bit color try starting your |
| 54 | X server in 32-bit per pixel mode for better performance. That is, |
| 55 | start your X server with |
| 56 | startx -- -bpp 32 |
| 57 | instead of |
| 58 | startx -- -bpp 24 |
| 59 | <li> Try disabling dithering with the MESA_NO_DITHER environment variable. |
| 60 | If this env var is defined Mesa will disable dithering and the |
| 61 | command glEnable(GL_DITHER) will be ignored. |
| 62 | </ol> |
| 63 | |
| 64 | |
| 65 | </BODY> |
| 66 | </HTML> |