A Soft Implementation Of ARB_gpu_shader_fp64 Is Slowly Being Tackled For Mesa

[phoronix]

Phoronix: A Soft Implementation Of ARB_gpu_shader_fp64 Is Slowly Being Tackled For Mesa

Last year there was a Google Summer of Code student working on a library to implement double-precision operations (FP64) in pure GLSL 1.30 as a benefit to older GPUs not having native FP64 capabilities. While that work didn't materialize as a solution in 2017 for those wanting "soft" ARB_gpu_shader_fp64 for being able to potentially expose OpenGL 4.0 on more R600g era GPUs, the work is ongoing...

http://www.phoronix.com/scan.php?page=news_item&px=FP64-libSoftFloat-February-Mesa

[davidbepo]

given that fp64 isnt used by games why not just fake the opengl version?

[Veerappan]

given that fp64 isnt used by games why not just fake the opengl version?

If you're going to go that route you might as well just override the GL version or extensions exposed on a per-application basis... We shouldn't get in the habit of lying about support for features that would cause an application to crash if the tried to use it after the driver said that feature was supported.

[TumultuousUnicorn]

given that fp64 isnt used by games why not just fake the opengl version?

I think it wouldn't pass the CTS. That is not because game doesn't use we can do that, what about software who really need that?
Just overwrite GL version with environment variable if you are sure what you do.

[davidbepo]

i mean that it should be overriden so r600 users can play opengl 4 games out of the box
for example hd 6870 is still a capable card, and some users wont be able to play games on it (not everybody knows how to override the GL version)
not perfect, but i think it's the best thing for end users

[Adarion]

I hope it'll be finished and coming soon. There is still enough old HW around that is still useful and would benefit from this. And some HW you can't easily replace with a modern GPU (e.g. laptops, thin clients and the like, basically anything soldered or with older slots or limited overall capacities).

Moreover it makes waiting for Vega easier.

[pal666]

i mean that it should be overriden so r600 users can play opengl 4 games out of the box

so what is stopping you from overriding it with environment variable?

[smitty3268]

r600 drivers still won't play most modern GL4 games out of the box with fp64, because they don't have a bunch of the GL 4.3 features like SSBO, compute shaders, etc.

[davidbepo]

so what is stopping you from overriding it with environment variable?

me, nothing.
newbie users, read the comment

[eydee]

The main problem with overriding the GL version number is that certain applications make multiple contexts, using different GL versions. If there is a global override in place, all of these contexts will end up being the forced version, and the application may consider it a failure. Examples: Talos (Serious Engine), Apitrace, Steam client etc. Having a working, but slow and never used, or even a faked implementation would allow these programs to work as expected.