This is an extraction of the Mesa 3-D library's software rasterizer and
offscreen rendering implementation of OpenGL 2.1 style APIs.  The 7.0.4 release
of Mesa is the original source of this code, although it has been scrubbed down
and modded a little for the purposes of minimalism.  (This fork is not
affiliated with the Mesa project - for the modern implementation see
https://mesa3d.org)

The goals of this particular fork are NOT speed, but rather a portable,
reliable, self contained, cross platform rendering method that does not require
ANY outside support from the OS or graphics hardware.  The idea is to guarantee
an application's ability to produce scene rasterizations as image data even
when the primary graphics stack of the machine is unavailable. It also aims to
be as trouble free as possible when it comes to things like API stability and
maintenance requirements.

The core libosmesa library deliberately does not have ANY external dependencies
on any libraries beyond the core C/C++ system libraries - this makes it as
insensitive as possible to changes in operating system environments.  Because
displaying the image data on screen is outside the scope of libosmesa, it is
also not tied to any operating system's window system API.  It just hands the
caller the rasterized image data - any subsequent display is up to higher
layers of the application's library stack.

The examples directory DOES have some external dependencies on graphical
toolkits, in order to provide some graphical application example.  The example
building may be disabled by setting -DOSMESA_BUILD_EXAMPLES=OFF.  The examples
directory itself may also be removed completely if a project bundling the
libosmesa sources doesn't wish to include it - the build system will adapt
appropriately.

Source code changes are (or at least are intended to be) relatively minor and
include things like static analyzer clean-ups and updating header includes to
avoid accidentally including system versions of gl.h.