Shaders & disabling shaders

[robn]

I was thinking of helping the official Intel drivers.
I don't expect good performance from the open source ones, there's just too little information for them to exploit the architecture and too little experience and resources to compete with the manufacturers in those terms. So I'm happy that they're/we're able to run comfortably on them.

On Linux the official drivers are the open source drivers - they released all the docs and hired many of the core X & Mesa devs to get it done. I was under the impression for some reason that they were the Windows drivers as well.

[robn]

I have glsl-optimizer building (build wasn't quite right for Linux). I'll run them over our shaders and test, and post a mod for others to try.

(edit: ...later. Not quite as fire-and-forget as I'd hoped, the compiler doesn't seem to have a way to pass defines and includes, which is pretty necessary. I'm at work now so can't really play too much right now).

[FluffyFreak]

My plan for that was to dump a shader to file, then pass that file into glsl-optimizer and save out the result.
Mostly just to test what it was doing and what we might be able to do up-front for optimisation :)

[FluffyFreak]

I was under the impression for some reason that they were the Windows drivers as well.

That wouldn't make sense for the older drivers since there's a disparity between the versions that are supported, 1.5 Win vs 2.0 Linux for the older ones which I imagine some people are using if they're legacy ex-work laptops. Even some of the newer ones are still 2.0 Win vs 2.1 Linux which wouldn't make sense if they were the same underlying driver code.

[robn]

So I did a hackish test with glsl-optimizer. Its on robn/glsl-optimizer-hack. Its not integrated, it actually calls out to the glslopt command and does some horrible tempfile hacks. It was just to see if there was any particular advantage.

On Linux, grab glsl-optimizer, and apply this patch to make it build. The compile Pioneer with robn/glsl-optimizer-hack, and run it as:

Code: Select all

GLSLOPT=/path/to/glslopt ./pioneer

It'll create a bunch of crud in /tmp to boot!

I didn't test extensively, but I didn't notice any appreciable difference on Intel on Linux. To be expected probably, since as noted, Intel uses Mesa for its drivers on Linux, and that's where the optimizer came from!

Using it properly is actually tough for us right now, because we actually compose shaders at run time with library files and different defines in place. So we would either have to link with glsl-optimizer directly (icky, there's quite a bit of code there) or we'd have to change our shader structure so we can compose them at compile time. Not to mention having a compiler that will work on all the platforms we use.

So this is almost certainly not useful for anyone, but there it is. Do what you will with it :)

[FluffyFreak]

Cheers robn :)

[robn]

This thread derailed rather quickly. The original question still stands though - if we killed shaderless, could anyone not run Pioneer (as opposed to merely inconvenient)?

It comes up again because of #2525. As we get more and more nice things its going to be harder to maintain both codepaths.

[Tichy]

I always played with shaders enabled except when I was trying to guess the cause of the ati linux free drivers issue,

[FluffyFreak]

I keep forgetting that we have a non-shader build, even my old PowerMac G4 has a gpu that can run this with shaders.

[jpab]

Debugging SDL2/OpenGL initialisation issue reported by forum user 'Core' has been moved to SDL2 crahes / startup issues.