This patch enables multisample antialiasing in the OpenSWR software renderer.
MSAA is a proof-of-concept/work-in-progress with bug fixes and performance
on the way. We wanted to get the changes out now to allow several customers
to begin experimenting with MSAA in a software renderer. So as not to
impact current customers, MSAA is turned off by default - previous
functionality and performance remain intact. It is easily enabled via
environment variables, as described below.
It has only been tested with the glx-lib winsys. The intention is to
enable other state-trackers, both Windows and Linux and more fully support
FBOs.
There are 2 environment variables that affect behavior:
* SWR_MSAA_FORCE_ENABLE - force MSAA on, for apps that are not designed
for MSAA... Beware, results will vary. This is mainly for testing.
* SWR_MSAA_MAX_SAMPLE_COUNT - sets maximum supported number of
samples (1,2,4,8,16), or 0 to disable MSAA altogether.
(The default is currently 0.)
Reviewed-by: George Kyriazis <george.kyriazis@intel.com>
Bruce Cherniak
1832ef6cd9