docs/perf.html

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   3 <TITLE>Performance Tips</TITLE>
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   7 <H1>Performance Tips</H1>
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   9 <p>
  10 Performance tips for software rendering:
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  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>
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