[Merged by Bors] - Request WGPU Capabilities for Non-uniform Indexing

[cryscan]

Objective

Fixes #6952

Solution

• Request WGPU capabilities SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING, SAMPLER_NON_UNIFORM_INDEXING and UNIFORM_BUFFER_AND_STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING when corresponding features are enabled.
• Add an example (shaders/texture_binding_array) illustrating (and testing) the use of non-uniform indexed textures and samplers.

Changelog

• Added new capabilities for shader validation.
• Added example shaders/texture_binding_array.

[IceSentry]

What happens when those features are not available? Should it just be user configurable instead of always asking for it?

[cryscan]

According to

bevy/crates/bevy_render/src/render_resource/shader.rs

Lines 184 to 211 in 49d50bd

	pub fn get_module_descriptor(
	&self,
	features: Features,
	) -> Result<ShaderModuleDescriptor, AsModuleDescriptorError> {
	Ok(ShaderModuleDescriptor {
	label: None,
	source: match self {
	ProcessedShader::Wgsl(source) => {
	#[cfg(debug_assertions)]
	// Parse and validate the shader early, so that (e.g. while hot reloading) we can
	// display nicely formatted error messages instead of relying on just displaying the error string
	// returned by wgpu upon creating the shader module.
	let _ = self.reflect(features)?;
	ShaderSource::Wgsl(source.clone())
	}
	ProcessedShader::Glsl(_source, _stage) => {
	let reflection = self.reflect(features)?;
	// TODO: it probably makes more sense to convert this to spirv, but as of writing
	// this comment, naga's spirv conversion is broken
	let wgsl = reflection.get_wgsl()?;
	ShaderSource::Wgsl(wgsl.into())
	}
	ProcessedShader::SpirV(source) => make_spirv(source),
	},
	})
	}
	}

and the caller

bevy/crates/bevy_render/src/render_resource/pipeline_cache.rs

Line 206 in 49d50bd

.get_module_descriptor(render_device.features())

, only available features are passed in. If certain features are not available, the corresponding capabilities won't be requested, and there will be a validation error only if the features are actually used in the shader.

[IceSentry]

Couple of nits, but overall LGTM

[IceSentry]

Suggested change

	description = "A shader that shows how bind and sample multiple textures as a binding array (a.k.a. bindless textures)."
	description = "A shader that shows how to bind and sample multiple textures as a binding array (a.k.a. bindless textures)."

[IceSentry]

For the sake of keeping the example simple I'd just remove this ifdef and assume it's always present

[IceSentry]

This should be a doc comment at the top of the file with the //! syntax

[robtfm]

looks good.

[robtfm]

can we pls check the capabilities in the demo, (both to show how it's done, and what is required)?

[cryscan]

Sure, will do!

[robtfm]

would be great to get this into the derive macro. i don't think we need to block on that but lets add an issue at least when this is merged.

[cryscan]

Yes. It's worth noting that AsBindGroup has a limitation that bind_group_layout() is a static function, and that's why there needs a constant MAX_TEXTURE_COUNT here.

[robtfm]

is this the right feature->capability pair?

[cryscan]

There is no Features::SAMPLER_NON_UNIFORM_INDEXING. This capability is required to have non-uniform indexed samplers, usually in pair with the usage of non-uniform indexed textures.

[superdump]

bors r+

[bors]

Pull request successfully merged into main.

Build succeeded:

• build-and-install-on-iOS
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