docs/osmesa.html - third_party/mesa - Git at Google

 <HTML>

 <TITLE>Off-screen Rendering</TITLE>

 <link rel="stylesheet" type="text/css" href="mesa.css"></head>

 <BODY>

 <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 RGBA pixels occupy 8 bytes.  When using 32-bit
    channels, channels are GLfloats and RGBA pixels occupy 16 bytes.
 </p>
 <p>
    To build Mesa/OSMesa with 16-bit color channels:
 <pre>
       make realclean
       make linux-osmesa16
 </pre>

    For 32-bit channels:
 <pre>
       make realclean
       make linux-osmesa32
 </pre>

 <p>
 You'll wind up with a library named libOSMesa16.so or libOSMesa32.so.
 </p>

 <p>
 If you need to compile on a non-Linux platform, copy Mesa/configs/linux-osmesa16
 to a new config file and edit it as needed.  Then, add the new config name to
 the top-level Makefile.  Send a patch to the Mesa developers too, if you're
 inclined.
 </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>
	<HTML>

	<TITLE>Off-screen Rendering</TITLE>

	<link rel="stylesheet" type="text/css" href="mesa.css"></head>

	<BODY>

	<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 RGBA pixels occupy 8 bytes. When using 32-bit
	channels, channels are GLfloats and RGBA pixels occupy 16 bytes.
	</p>
	<p>
	To build Mesa/OSMesa with 16-bit color channels:
	<pre>
	make realclean
	make linux-osmesa16
	</pre>

	For 32-bit channels:
	<pre>
	make realclean
	make linux-osmesa32
	</pre>

	<p>
	You'll wind up with a library named libOSMesa16.so or libOSMesa32.so.
	</p>

	<p>
	If you need to compile on a non-Linux platform, copy Mesa/configs/linux-osmesa16
	to a new config file and edit it as needed. Then, add the new config name to
	the top-level Makefile. Send a patch to the Mesa developers too, if you're
	inclined.
	</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>