Remove ExtractedView::hdr, add ExtractedView::texture_format, move compositing_space to ExtractedCamera

[atlv24]

Objective

• Clean up our texture format handling.
• Fix Hdr required to get rendertarget to respect TextureFormat #23732
• Get us closer to HDR Display Output #22563
• It makes no sense for views to talk about being hdr or not. They have a texture format, that's it. What does HDR shadows even mean lol
• Same for compositing_space

Solution

• Remove ExtractedView::hdr
• Add ExtractedView::texture_format
• Move ExtractedView::compositing_space to ExtractedCamera::compositing_space
• Add texture_format to a bunch of specialization keys instead of hdr bool
• Convert VolumetricFogPipelineKey to not use flags and just use bool and texture format

Testing

• Completely untested, didnt even run an example. @salixsalicaceae pls help

This needs a migration guide.

[github-actions]

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[jasmine-nominal]

Can you add docs to ExtractedCamera/View clarifying the differences between them? (view can be any sort of rendering thing e.g. a shadow map, camera is stuff relevant to an actual camera)

[IceSentry]

Suggested change

	texture_format: TextureFormat,
	/// Texture format of the view target
	texture_format: TextureFormat,

[atlv24]

there's some semantics I want to figure out before writing this comment, specifically with how Hdr overrides the window texture format and uses a different internal. Still thinking

[IceSentry]

I really like the direction of this PR, bit +1 from me once CI is passing.

[tychedelia]

Ty, this is a helpful step towards some other goals I have here. I'm wondering for a few of these passes where you switched to camera.hdr, is there a strong reason not to have them use the view target texture?

[tychedelia]

hrm... yeah, don't love this. i think with how much we've improved specialization the cost of having a bigger mesh key would be worth investigating, it could totally be whatever

[atlv24]

yeah I think its fine, i think its the only iffy part. its not hard to have a followup yeet it and be independently benchmarked though

[beicause]

but mesh pipeline keys have limited space.

Not really. In #22637 I made texture format a part of mesh key.

[mate-h]

I like the direction you're proposing! very nice. Extracted views really shouldn't care about hdr or compositing space or not, cameras should. I did a bunch of research and testing for this PR and I tried fixing the 2d hdr bloom, 3d scene examples and also created a compositing space example. While trying not to reintroduce any of the antipatterns being cleaned up in this PR. atlv24#5

[beicause]

I hope we could put all webgpu renderable && blendable formats into the mesh pipeline key to reduce collisions with #22637. But I'm not against the current either.