release: v0.34.6

[kolkov]

Patch release: pipeline-overridable constants now work on every backend, a GLES crash fix, and the naga and goffi bumps. The v0.34.6 CHANGELOG section also covers what merged since v0.34.5: #367 (usage scopes per pass), #366, #363, #362 and #359.

Fixed

• Pipeline-overridable constants were ignored; @workgroup_size(<override>) compiled as 1. No backend processed WGSL override declarations, so ComputePipelineDescriptor.Constants had no effect and an override-sized workgroup ran with size 1: a @workgroup_size(n, 2) shader with n = 4 ran 2 invocations instead of 8 on Vulkan, DX12 and GLES. Each backend now specializes the module per pipeline stage with naga.ProcessOverrides before the shader backend, as Rust wgpu-hal does (vulkan/device.rs, dx12/device.rs, gles/device.rs, metal/device.rs); modules without overrides keep the compile-once path. On DX12 the constants are part of the DXIL cache key.

• GLES fence polling without the GL context. Queue.PollCompleted, Device.Wait and Device.GetFenceStatus called glGetSynciv / glClientWaitSync without taking the adapter context, so the call ran on whatever OS thread the caller was on, with no GL context current. With Intel's Windows GL driver Device.Poll (reached from Buffer.Map) crashed with an access violation. They now take the context first, as Rust wgpu-hal does (gles/device.rs get_fence_value, wait).

• GLES texture readback came back mirrored, with R and B swapped. CopyTextureToBuffer read with a hard-coded GL_BGRA, flipped the rows (shaders already use naga's ADJUST_COORDINATE_SPACE, so texture row 0 is the image top) and ignored bytesPerRow: examples/triangle-headless on GLES returned a blue, upside-down triangle, and 256-byte-pitch readbacks were sheared. A copy that did not fill the whole destination buffer read back zeros, because MapBuffer uses the CPU shadow only when it covers the buffer. It now reads in the texture's own transfer format and type, keeps memory row order, writes rows at bytesPerRow and keeps the rest of the buffer; CopyBufferToTexture sets GL_UNPACK_ROW_LENGTH from bytesPerRow. Both as in Rust wgpu-hal gles/queue.rs. The GLES output of triangle-headless is now byte-identical to Vulkan's.

• GLES (Linux) CreateTexture failed on an earlier call's GL error. On Mesa's d3d12 driver in WSL the first texture after device creation failed with GL_INVALID_ENUM left by a previous call; stale errors are now drained and logged before the allocation, so triangle-headless runs there.

• Software CopyBufferToTexture ignored bytesPerRow, rowsPerImage and the origin, copying one tight block to the start of the texture. Rows are now copied into the region at the texture origin.

Changed

• Unknown pipeline-constant keys are an error. A Constants key that names no override now fails pipeline creation with naga's *PipelineConstantError instead of being ignored. Per the WebGPU spec the key of @id(N) override x is "N".
• Dependencies: naga v0.19.0 → v0.20.3 (naga.ProcessOverrides), goffi v0.6.3 → v0.6.7. goffi v0.6.6+ refuses calls whose argument count differs from the call interface; a static check of all 770 ffi.CallFunction sites found no mismatch. The Android preview check pins goffi v0.6.7, since it asserts the exact version.
• Dependency versions in README, AGENTS.md, ROADMAP, ARCHITECTURE and the Android preview docs.

Testing

• New override tests through the public API and on every adapter: workgroup size from defaults and from constants, overrides in arithmetic, by @id and by name, an array sized by an anonymous override, unknown keys, render stages. 116 pass on Windows (Vulkan on Intel and NVIDIA, DX12 FXC and DXIL on both, GLES, Software). The workgroup cases fail on main on Vulkan, DX12 FXC, DX12 DXIL and GLES.

• TestFencePollingTakesAdapterContext holds the adapter context from another goroutine and checks that each of the three calls waits for it; it fails on main for all three.

• Builds for windows/amd64, linux/amd64, linux/arm64, darwin/arm64, darwin/amd64, js/wasm and -tags rust; golangci-lint clean on Windows, Linux and macOS; tests on Windows and Linux.

• Adapters without compute shaders (Mesa's d3d12 GL driver in WSL) skip the compute cases, as Rust's test harness does with downlevel_flags.

• TestTextureCopyRoundTrip uploads four colors with WriteTexture and with a 256-byte-pitch CopyBufferToTexture and reads them back with a 256-byte pitch on every backend; on main it fails for GLES (both uploads) and for the software CopyBufferToTexture.

• examples/triangle-headless on Vulkan (validation layer clean), DX12, GLES and Software on Windows, and GLES on Mesa d3d12 in WSL: identical output.

Not verified

• macOS/Metal: the override change and goffi v0.6.7 are not yet run on a Mac.

[codecov]

Codecov Report

❌ Patch coverage is 63.49206% with 23 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/shaderir/shaderir.go	63.49%	18 Missing and 5 partials ⚠️

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