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