Drop ASTC requirement in compatibility mode.

[SenorBlanco]

OpenGL ES 3.1 does not require support for ASTC texture formats.

See #4266 (comment)

[github-actions]

Previews, as seen when this build job started (a0d8117):
WebGPU _{webgpu.idl | Explainer | Correspondence Reference}
WGSL _{grammar.js | wgsl.lalr.txt}

[kainino0x]

This was discussed but doesn't seem like we wrote down a resolution:
https://github.com/gpuweb/gpuweb/wiki/GPU-Web-2024-01-24#astc-textures-arent-required-until-es-32-cant-require-them-in-compat-todo

Guess we should raise it tomorrow (I'm certain it will be quick).

[teoxoy]

Do we have to drop this requirement?

Looking at https://opengles.gpuinfo.org/listreports.php?extension=GL_KHR_texture_compression_astc_ldr&option=not and filtering for OpenGL ES 3.1 I could find the following noteworthy chips:

• Mali-T604 on android 5¹
• Mali-T830 on android 7²
• PowerVR Rogue G6200 on android 5-7¹
• PowerVR Rogue G6430 on android 5-7¹
• A few Adreno devices on android 4-7 and one on 9²

Footnotes

1. already dropped in https://github.com/gpuweb/gpuweb/issues/4417 ↩ ↩² ↩³

2. there are a lot more reports that support the extension ↩ ↩²

[SenorBlanco]

Thanks for doing the legwork, Teo! I think we discussed this issue before in the group, but we couldn't find a consensus in the notes. Agreed that Android looks ok for ASTC support. I'll hold off on merging this for now. We're going to do some investigation on the ChromeOS side, and if support looks good there as well, I'll drop this issue.

[Kangz]

GPU Web CG 2024-04-10 Atlantic-time

• SW: ASTC isn't core until GLES 3.2. Propose we validate this out. In Compat, required only to have BC or ETC2.
• CW: Teo says on Android, essentially all devices support ASTC in GL. Other devices we care about for Compat that don't support BC?
• KG: it's unfortunate to have ETC2 as the only available option.
• KR: Android graphics dashboards still have a lot of GLES 3.1 devices. Do they have the ASTC extension?
• KN: yes, Teo looked at widespread extension support of the ASTC extension.
• CW: Need to look at the data on ChromeOS but at least for Android we don't need to remove ASTC.
• CW: Action: check with ChromeOS folks. If there's widespread ASTC support, we'll close this issue.