MSAA For Mesa Finally Moves Closer

[anbog]

Support for evergreen/cayman and WIP support for 6xx/7xx is available here:

http://cgit.freedesktop.org/~airlied/mesa/log/?h=r600g-ms

Support for r3xx-r5xx shouldn't be too hard to add. See section 10.8 of the r5xx acceleration programming documentation:
http://www.x.org/docs/AMD/R5xx_Acceleration_v1.5.pdf

I'm not a programmer, though I'm slowly starting to build some basic skills, so I don't really understand how the documentation is translated to code. Do you know of walk-through example of this? Like a blog post detailing how a specific feature was implemented (in some level of detail)? It could be an interesting read!

[bug77]

I did read somewhere that MSAA is actually required in GL 3.0 and later? If this is true? I mean Intel has been advertising GL 3 for a while now and the only add MSAA now?

Idk about "required", but it has been around since like OpenGL 1.5

[calim]

Nouveau.

Excuse me, but nouveau/nv50,nvc0 have been supporting MSAA for a year now (http://cgit.freedesktop.org/mesa/mes...2820b00a9ce667).

[curaga]

Michael, this is wrong:

MLAA in Mesa though is done on the CPU

It runs entirely on the GPU.

Of course Mesa as a whole may be cpu-limited, but please don't confuse the two

[curaga]

I'm not a programmer, though I'm slowly starting to build some basic skills, so I don't really understand how the documentation is translated to code. Do you know of walk-through example of this? Like a blog post detailing how a specific feature was implemented (in some level of detail)? It could be an interesting read!

For an extremely simple feature (ROUND support), it went something like
- read the docs to pick a suitable opcode, if it exists
- check the right file on how the other opcodes around it are implemented, copy-paste a suitable function / add an argument to the handler
- bind it to that function in the tables for the hw

And the result:

http://cgit.freedesktop.org/mesa/mesa/commit/?id=df7859be6b6b6c227e7a4e0b7fbfafcd0800f4f8

[bridgman]

I did read somewhere that MSAA is actually required in GL 3.0 and later? If this is true? I mean Intel has been advertising GL 3 for a while now and the only add MSAA now?

My understanding is that MSAA *is* required for GL 3.0 but this was only realized *after* drivers started advertising 3.0 support.

I don't think it was just a simple oversight -- IIRC there was some nuance with earlier GL versions where the extension had to be supported but only 1x support was required (which meant that real MSAA support was *not* really needed at that point).

[Hirager]

My understanding is that MSAA *is* required for GL 3.0 but this was only realized *after* drivers started advertising 3.0 support.

I don't think it was just a simple oversight -- IIRC there was some nuance with earlier GL versions where the extension had to be supported but only 1x support was required (which meant that real MSAA support was *not* really needed at that point).

Not sure what changed -- if 3.0 required more than 1x and that was missed, or if there was a realization that the "1x only" interpretation was wrong... or completely unrelated

Something like undiscovered dependency in package management?

[bridgman]

More likely a missed nuance in a 200-page specification...

[russofris]

More likely a missed nuance in a 200-page specification...

At least it wasn't one of those nuances filled with double negatives that you have to re-read two dozen times and draw a UML diagram of in order to offer a hypothesis about what the spec is trying to tell you, all while you do your best to suppress a psychotic episode where you fantasize about the authors' demise.

Just thinking about it fills me with feelings and emotions that no man should be encumbered with in a professional or academic setting.

F

[DavidC]

BTW, there's no support for MSAA pre-Gen 6 because only Sandy Bridge onwards have hardware for it.