Bug#1116031: nexuiz: Does not start on Vivante GC7000 GPU: GLXBadFBConfig

[Ælla Chiana Arson Bobbie Moskopp]

Simon McVittie <smcv at debian.org> writes:

> Control: tags -1 + wontfix
>
> On Tue, 23 Sep 2025 at 21:52:53 +0200, Ælla Chiana Arson Bobbie Moskopp wrote:
>>    Max core profile version: 0.0
>>    Max compat profile version: 2.1
>
> Sorry, this is just not an OpenGL functionality level that is supported 
> by this game engine. Since 2019, it requires OpenGL 3.2. This was an 
> upstream change that was made intentionally, so it is unlikely to be 
> reverted in future versions of the engine.

I have seen this several times already. IMO the reason is that 3D game
developers often have much better hardware than (casual) players, thus
skewing their perception of requirements upwards. It's a losing battle
to try to convince people with gaming GPUs that not everyone has them,
and a few years after games drop the renderers that make games go fast
on older and weaker hardware, affected users stop playing those games.

> If Mesa's Vivante driver is providing misleading version information and 
> the driver actually has better functionality than what it advertises, 
> that would be something to take up with the driver's developers (but 
> bear in mind that this is a reverse-engineered driver for a 10+ year old 
> GPU design, so don't expect miracles).
>
>      smcv

I have asked in #etnaviv on the OFTC IRC network and austriancoder gave
me the following explanation for underreporting driver OpenGL versions:

> there are reason why we do not expose higher opengl versions - some
> required features like 128 bit formats are not supported by the gpus
> and need to be emulated. a fancy feature from a higher opengl version
> works per se, but the spec requires support for 128 bit
> formats. that's why you might see a perf boost.

To me this seems similar to the situation in which the Mesa drivers for
older Intel integrated GPUs intentionally report to support only OpenGL
1.x instead of 2.x; because otherwise applications (like Chrome) choose
a rendering path that uses newer OpenGL, but is slower on the hardware.

Given that evidently darkplaces works with the GPU in my MNT Reform 2
(and possibly other GPUs that report lower OpenGL version numbers for
similar reasons), I wonder though if setting the environment variable
could be added to a launch wrapper … would that create other issues?
The worst I would assume is a crash or seeing a very slow main menu.

I vaguely remember that there used to be some configuration to adjust
graphics options for specific applications … I do not recall details.