[Mesa-dev] The GL3.txt format

[Roland Scheidegger]

Yeah I guess so. I think we were lazy updating GL3.txt for these
drivers, I'll whip up a patch.

Roland

Am 25.08.2014 16:41, schrieb Romain Failliot:
> Could it be possible to add these drivers in the lists instead of me
> adding some more exceptions in my code?
> 
> (I ask that mainly because I might have bug reports saying that softpipe
> is green but it's never mentioned in the original file)
> 
> 
> 2014-08-25 10:28 GMT-04:00 Roland Scheidegger <sroland at vmware.com
> <mailto:sroland at vmware.com>>:
> 
> 
>     Am 25.08.2014 07 <tel:25.08.2014%2007>:56, schrieb Kenneth Graunke:
>     > On Monday, August 25, 2014 12:05:07 AM Romain Failliot wrote:
>     >> Some folks helped me and a lot of detection bug have been fixed!
>     >>
>     >> I have a question though (for my own culture): what's with the
>     swrast, the
>     >> softpipe and the llvmpipe? Aren't they all software drivers?
>     What's the
>     >> difference between all of them?
>     >>
>     >> Thanks you!
>     >
>     > swrast is Mesa's original software rasterizer - the oldest of the
>     three.  In addition to being a standalone software driver, it's also
>     used for software fallbacks in the classic drivers (i915, i965,
>     r100, r200, nouveau_vieux).
>     >
>     > softpipe is newer - a Gallium based software rasterizer.  It has a
>     lot more features than the old swrast.  It's not particularly fast,
>     but is pretty simple in comparison to llvmpipe.
>     >
>     > llvmpipe uses LLVM to compile shaders to native assembly, rather
>     than using an interpreter.  As such, it's much faster than the other
>     two.
>     >
>     > At least, that's my understanding of the situation.
>     >
>     > --Ken
> 
>     In addition to that, softpipe is more meant as a development tool - way
>     easier to debug if something goes wrong than llvmpipe. It is lagging a
>     bit behind llvmpipe though in some areas.
>     llvmpipe, while not listed in GL3.txt, actually can do all up to and
>     including GL 3.3, with the exception of real MSAA (the implementation is
>     fake and not conformant). Similar story with softpipe (though it has
>     more non-compliant behavior wrt texturing especially, like explicit
>     derivatives not working, no offsets etc.).
> 
>