Bring immediate api in line with spec

[cwfitzgerald]

Connections

#8556

Description

This brings the api in line with the spec. Notably we still do zeroing, which is not spec compliant. This will be fixed in a future change.

Diff is great.

Mac setup is a bit wasteful as we upload to all stages, even ones not part of the current pipeline, but we would have to refactor our handling of immediates quite a bit to get stage information in wgpu-hal as the set_immediate call would need to always happen after we know the pipeline we're referring to, and it's not clear to me that this is worth bothering with.

Testing

See Eye, Locally

Squash or Rebase?

COMMIT

TODO

• Fix mac

[JMS55]

Does this fix #5683 ?

[cwfitzgerald]

@JMS55 no, but I'll add that to the tracking issue.

[Copilot]

Pull request overview

This PR brings the immediate data API (formerly known as push constants) in line with the WebGPU specification. The changes simplify the API by removing per-stage configuration in favor of a unified size, and eliminate the stages parameter from upload functions.

Key changes:

• Replaced immediates_ranges: &[ImmediateRange] with immediate_size: u32 in PipelineLayoutDescriptor
• Removed stages: ShaderStages parameter from all set_immediates() function calls
• Renamed IMMEDIATES_ALIGNMENT to IMMEDIATE_DATA_ALIGNMENT throughout the codebase

Reviewed changes

Copilot reviewed 100 out of 100 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
wgpu/src/api/pipeline_layout.rs	Updated descriptor to use single size field instead of ranges
wgpu/src/api/render_pass.rs	Simplified set_immediates API, removed stage parameter
wgpu/src/api/render_bundle_encoder.rs	Updated set_immediates signature
wgpu/src/util/encoder.rs	Updated trait definition for set_immediates
wgpu/src/lib.rs	Removed ImmediateRange export, renamed constant
wgpu-types/src/lib.rs	Removed ImmediateRange struct, renamed constant
wgpu-core/src/binding_model.rs	Simplified validation logic and error types
wgpu-core/src/device/resource.rs	Updated pipeline layout creation and validation
wgpu-core/src/command/*.rs	Updated command encoding to use new API
wgpu-hal/src/*/device.rs	Updated backend implementations for new descriptor
wgpu-hal/src/*/command.rs	Removed stages parameter from hal command encoders
tests/**/*.rs	Updated all test code to use new API
examples/**/*.rs	Updated all example code to use new API
CHANGELOG.md	Added migration guide for the API change

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[Copilot]

Pull request overview

Copilot reviewed 100 out of 100 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (1)

wgpu/src/backend/webgpu.rs:1

• Corrected spelling of 'multi_draw_indexed_indirect' to 'set_immediates' in panic message.

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[teoxoy]

Nice! Much simpler 👀