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diff --git a/docs/osmesa.html b/docs/osmesa.html index 6feb8df52a0..629d054f419 100644 --- a/docs/osmesa.html +++ b/docs/osmesa.html @@ -10,46 +10,57 @@ <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. +Mesa's off-screen rendering interface is used for rendering into +user-allocated blocks of memory. +That is, the GL_FRONT colorbuffer is actually a buffer in main memory, +rather than a window on your display. +There are no window system or operating system dependencies. +One potential application is to use Mesa as an off-line, batch-style renderer. </p> + <p> -The "OSMesa" API provides 3 functions for making off-screen +The <B>OSMesa</B> API provides three basic 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. +more information about the API functions. </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. +There are several examples of OSMesa in the <code>progs/osdemo/</code> +directory. </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. +For some applications 8-bit color channels don't have sufficient +precision. +OSMesa 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: +Before version 6.5.1, Mesa had to be recompiled to support exactly +one of 8, 16 or 32-bit channels. +With Mesa 6.5.1, Mesa can be compiled for either 8, 16 or 32-bit channels +and render into any of the smaller size channels. +For example, if Mesa's compiled for 32-bit channels, you can also render +16 and 8-bit channel images. +</p> + +<p> +To build Mesa/OSMesa for 16 and 8-bit color channel support: <pre> make realclean make linux-osmesa16 </pre> - For 32-bit channels: +<p> +To build Mesa/OSMesa for 32, 16 and 8-bit color channel support: <pre> make realclean make linux-osmesa32 @@ -57,6 +68,13 @@ memory. <p> You'll wind up with a library named libOSMesa16.so or libOSMesa32.so. +Otherwise, most Mesa configurations build an 8-bit/channel libOSMesa.so library +by default. +</p> + +<p> +If performance is important, compile Mesa for the channel size you're +most interested in. </p> <p> @@ -66,12 +84,5 @@ 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> |