[meta] Feature Testing Checklist

[kvark]

Now that we got #786, we should start taking advantage of it by introducing local "playtests".
We can take wgpu-rs example matrix as a baseline:

• vertex attributes
• instancing
• lines and points
• sampled color textures
• storage textures
• binding array
• comparison samplers
• subresource views
• cubemaps
• multisampling
• off-screen rendering
• stencil testing
• depth testing
• depth biasing
• read-only depth
• blending
• render bundles
• compute passes
• optional extensions
• - binding indexing
• - push constants
• WGSL shaders

Note-1: we don't have to be super detailed in testing all the features in the world. It's just one of the testing layers in "defence in depth" onion of layers, above gfx-rs running on Warden and Vulkan CTS, and below wgpu-rs and WebGPU CTS. Common sense should be applied to weight the maintenance overhead versus the test coverage. I think getting a test for an entry in the feature matrix is a great start.

Note-2: it's not clear what shaders we should be using here. I suggest we start with a single shader module that outputs a full-screen quad (without vertex attributes) in VS, and writes down a solid fixed color to the output in FS. Perhaps, we can write test shaders in WGSL right away as this thing is getting more and more mature?

[ncharlton02]

I'd be interested in working on this, but I was curious about a few things.

1. Should these tests be in the player/tests directory or in a separate dedicated crate?
2. For the shaders, is WGSL ready enough to be used? I have never used it but would be wiling to learn it

If you had any other insights that would be appreciated

[kvark]

1. player is already a dedicated development-only crate, so it's a good place to put the tests in. More specifically, into player/tests
2. I don't think WGSL is ready just yet. We can go a long way with just a single SPIR-V shader that is compiled from source off-line and just fills out the screen with some color, for now.

If you had any other insights that would be appreciated

We'd love to chat on "#wgpu:matrix.org"!

[cwfitzgerald]

Now that wgpu-rs is us and we have the ability to run the CTS, I'm going to close this as a lot of these things will be covered by the CTS.