updated docs for off-screen rendering

1 files changed, 39 insertions, 28 deletions

diff --git a/docs/osmesa.html b/docs/osmesa.html
index 6feb8df..629d054 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>
-
-
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