workbench/libs/mesa/docs/perf.html

   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>