Support Sliced 3D for ASTC

[mehmetoguzderin]

Connections

Fixes #7576

Description

This PR aims to enable "texture-compression-astc-sliced-3d" for backends that support ASTC (such as excluding D3D12).

If any aspects could be improved to make it more suitable for the project, please let me know, and I will adjust it. Thank you very much in advance!

Testing

Mainly cargo xtask test.

Squash or Rebase?

Squash

Checklist

• Run cargo fmt.
• Run taplo format.
• Run cargo clippy --tests. If applicable, add:
  • --target wasm32-unknown-unknown
• Run cargo xtask test to run tests.
• If this contains user-facing changes, add a CHANGELOG.md entry.

[mehmetoguzderin]

Adjusted after running cargo clippy --tests --target wasm32-unknown-unknown locally. Thank you!

[Wumpf]

thanks! Looks mostly good to me, some changes proposed in comments.

Would be great to have a test for this that generates astc textures, but iirc we don't have that for other compressed formats either :/

[Wumpf]

I'm a bit confused about the extension zoo here tbh. So apparently [WEBGL_compressed_texture_astc])https://registry.khronos.org/webgl/extensions/WEBGL_compressed_texture_astc/) implies all of KHR_texture_compression_astc_hdr, which in turn says It includes support for 2D and slice-based 3D textures, with low and high dynamic range, at bitrates from below 1 bit/pixel up to 8 bits/pixel in fine steps.
Which kinda implies that for webgl, either profile should imply sliced 3d.

The else block (native gl) should then instead check for GL_KHR_texture_compression_astc_sliced_3d to activate the feature.

[mehmetoguzderin]

@Wumpf good one, I missed the native GL block. I tried to address in latest commit! PLMK if it helps sufficiently.

[Wumpf]

would be nice to mention on the above feature that volume textures aren't included unless TEXTURE_COMPRESSION_ASTC_SLICED_3D is enabled.

Wondering what to do with the non-webgpu _HDR variant, seems a bit underspeced 🤔. I'm fine with ignoring that for now.

[mehmetoguzderin]

@Wumpf makes sense, does the new commit look sufficient?

[mehmetoguzderin]

@Wumpf Thank you very much for the review. Besides accepting the suggestion, I made a commit to address the other ones. For testing in general for compression maybe a tracking issue can be created however webgpu-samples already include an astc-compressed example data (and CTS covers ASTC Sliced 3D), or I can try to help in a consecutive PR to have it generate directly inside repo. Appreciated. Hope the commits help.