Feature for Min/Max filter modes

[kvark]

Is your feature request related to a problem? Please describe.
Min/Max sampler filter modes have widespread support in native APIs and are useful to reduce bandwidth requirements of a set of image processing operations, like building a mipmap chain for the depth buffer.

Describe the solution you'd like
Add an optional feature SAMPLER_FILTER_MINMAX as well as "Min" and "Max" variants to wgt::FilterMode. The feature should map to https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/VK_EXT_sampler_filter_minmax.html in Vulkan, and to FILTER_MINIMUM_*/FILTER_MAXIMUM_* in https://docs.microsoft.com/en-us/windows/win32/api/d3d12/ne-d3d12-d3d12_filter

Describe alternatives you've considered
Not exposing anything.

Additional context
Min/Max modes are not considering "filtering" modes for the purpose of texture/sampler bindings.

[kvark]

Spec PR - gpuweb/gpuweb#1283

[FuriouZz]

Hello there 👋🏽 What is the status of this issue? I will be glad to contribute.

[kvark]

@FuriouZz it's available! but very optional, since it's not going to be in WebGPU for the V1 release.

If you want to work on it, gfx-rs/gfx#3523 needs to be implemented first. The API in wgpu would probably need to adjust for it as well, i.e. instead of adding Min/Max to the wgt::FilterMode, we'd probably want to have a separate field called reduction_mode in the sampler descriptor.

[kvark]

I think the "good first issue" label is a bit of a mistake on my part here, given the reasoning in the previous comment. This is average difficulty, not easy, and not very urgent/important at this moment.

[FuriouZz]

Oh ok thanks. I will have look. I have made some exploration before asking. I will take a look.