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+<HTML>
+
+<TITLE>Off-screen Rendering</TITLE>
+
+<BODY text="#000000" bgcolor="#55bbff" link="#111188">
+
+<H1>Off-screen Rendering</H1>
+
+
+<p>
+Mesa 1.2.4 introduced off-screen rendering, a facility for generating
+3-D imagery without having to open a window on your display. Mesa's
+simple off-screen rendering interface is completely operating system
+and window system independent so programs which use off-screen
+rendering should be very portable. This feature effectively
+enables you to use Mesa as an off-line, batch-oriented renderer.
+</p>
+<p>
+The "OSMesa" API provides 3 functions for making off-screen
+renderings: OSMesaCreateContext(), OSMesaMakeCurrent(), and
+OSMesaDestroyContext(). See the Mesa/include/GL/osmesa.h header for
+more information. See the demos/osdemo.c file for an example program.
+There is no facility for writing images to files. That's up to you.
+</p>
+<p>
+If you want to generate large images (larger than 1280x1024) you'll
+have to edit the src/config.h file to change MAX_WIDTH and MAX_HEIGHT
+then recompile Mesa. Image size should only be limited by available
+memory.
+</p>
+
+
+<H2>Deep color channels</H2>
+
+<p>
+ For some applications 8-bit color channels don't have sufficient
+ accuracy (film and IBR, for example). If you're in this situation
+ you'll be happy to know that Mesa supports 16-bit and 32-bit color
+ channels through the OSMesa interface. When using 16-bit channels,
+ channels are GLushorts and pixels occupy 8 bytes. When using 32-bit
+ channels, channels are GLfloats and pixels occupy 16 bytes.
+</p>
+<p>
+ To build Mesa/OSMesa with 16-bit color channels:
+<pre>
+ cd Mesa-4.x/src
+ make -f Makefile.X11 clean
+ make -f Makefile.OSMesa16 linux-osmesa16
+</pre>
+
+ For 32-bit channels:
+<pre>
+ cd Mesa-4.x/src
+ make -f Makefile.X11 clean
+ make -f Makefile.OSMesa16 linux-osmesa32
+</pre>
+
+<p>
+If you're not using Linux, you can easily edit Make-config and add
+an appropriate configuration.
+</p>
+<p>
+The Mesa/tests/osdemo16.c file (available via CVS) demonstrates how
+to use this feature.
+</p>
+<p>
+BE WARNED: 16 and 32-bit channel support has not been exhaustively
+tested and there may be some bugs. However, a number of people have
+been using this feature successfully so it can't be too broken.
+</p>
+
+
+</BODY>
+</HTML>