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11 <h1>The Mesa
3D Graphics Library
</h1>
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17 <h1>Off-screen Rendering
</h1>
21 Mesa's off-screen rendering interface is used for rendering into
22 user-allocated blocks of memory.
23 That is, the GL_FRONT colorbuffer is actually a buffer in main memory,
24 rather than a window on your display.
25 There are no window system or operating system dependencies.
26 One potential application is to use Mesa as an off-line, batch-style renderer.
30 The
<b>OSMesa
</b> API provides three basic functions for making off-screen
31 renderings: OSMesaCreateContext(), OSMesaMakeCurrent(), and
32 OSMesaDestroyContext(). See the Mesa/include/GL/osmesa.h header for
33 more information about the API functions.
37 There are several examples of OSMesa in the mesa/demos repository.
41 <h2>Deep color channels
</h2>
44 For some applications
8-bit color channels don't have sufficient
46 OSMesa supports
16-bit and
32-bit color channels through the OSMesa interface.
47 When using
16-bit channels, channels are GLushorts and RGBA pixels occupy
49 When using
32-bit channels, channels are GLfloats and RGBA pixels occupy
54 Before version
6.5.1, Mesa had to be recompiled to support exactly
55 one of
8,
16 or
32-bit channels.
56 With Mesa
6.5.1, Mesa can be compiled for either
8,
16 or
32-bit channels
57 and render into any of the smaller size channels.
58 For example, if Mesa's compiled for
32-bit channels, you can also render
59 16 and
8-bit channel images.
63 To build Mesa/OSMesa for
16 and
8-bit color channel support:
70 To build Mesa/OSMesa for
32,
16 and
8-bit color channel support:
77 You'll wind up with a library named libOSMesa16.so or libOSMesa32.so.
78 Otherwise, most Mesa configurations build an
8-bit/channel libOSMesa.so library
83 If performance is important, compile Mesa for the channel size you're
88 If you need to compile on a non-Linux platform, copy Mesa/configs/linux-osmesa16
89 to a new config file and edit it as needed. Then, add the new config name to
90 the top-level Makefile. Send a patch to the Mesa developers too, if you're