DX12: Align copies b/w textures and buffers when `D3D12_FEATURE_DATA_D3D12_OPTIONS13.UnrestrictedBufferTextureCopyPitchSupported` is `false` by ErichDonGubler · Pull Request #7721 · gfx-rs/wgpu

ErichDonGubler · 2025-05-23T21:45:16Z

Connections

Likely resolves [d3d12] Panic in end_encoding #5285.
A case we need to handle for [d3d12] Support padded rows_per_image for 3D texture writes #4150.

Testing

@teoxoy and I proved on some custom DLLs copied from an old Windows machine that this works, both on older WARP adapters and when forcefully done in updated DX12 runtimes. So, we're definitely not breaking anything! It's hard to set up an environment to specifically test this, though.

Squash or Rebase?

rebase plz

Checklist

If this contains user-facing changes, add a CHANGELOG.md entry.

wgpu-hal/src/dx12/mod.rs

ErichDonGubler · 2025-07-24T20:48:22Z

Got the CI issue resolved! I was definitely doing something wrong. 👉🏻👈🏻 From community chat:

@ErichDonGubler:

I just paired with Teo, and we actually FIGGERED IT OUT!

@teoxoy and I sideloaded a bunch of DLLs from an ancient Windows 10 computer I had, which happened to have a WARP adapter that did not support low-alignment buffer-to-texture copies.

...turns out I accidentally swapped the alignment requirement branches. 😅

We had to work around:

Not having the right DLLs (because new versions have lower alignment needs) and stealing them from an old machine I happened to have around.

Crashing when trying to compile indirect buffer validation shaders (because old versions?)

Feature unification working against us when trying to use WGPU_VALIDATION_INDIRECT_CALL=0

Erich being dumb and necessitating debugging in the first place

It was an hours-long adventure, lemmetellyawhat.

@teoxoy:

It was fun :)

@cwfitzgerald:

oh boy!

that sounds like an adventure indeed

teoxoy

Looks good overall but we should also enable some CTS tests like the one in #5285.

wgpu-hal/src/dx12/command.rs

ErichDonGubler · 2025-10-09T00:47:54Z

Doing some branch pushes to check that webgpu:api,operation,command_buffer,image_copy:undefined_params:* fails before and after, and hopefully that it catches the bug @teoxoy found with region offsets being swapped on the tex-to-buf path. 🤞🏻

ErichDonGubler · 2025-10-09T01:13:40Z

Alright, so:

https://github.com/erichdongubler-mozilla/wgpu/actions/runs/18361970647/job/52307306029 is based on trunk, and has 4 failures, including some in 2d copies and 3d copies.
https://github.com/erichdongubler-mozilla/wgpu/actions/runs/18361971738/job/52307309175 is based on this PR's contents before the fix Teo identified for offsets in tex-to-buf. There are still 2d failures here, but fewer.
https://github.com/gfx-rs/wgpu/actions/runs/18362103668/job/52307694538?pr=7721 implements Teo's fix, and confirms that things get greener. Yay! Unfortunately, there are still breakages with 3d copies, so this whole thing isn't passing yet, but I'd say this is a nice confirmation that we're fixing something.

I'll figure out the exact set of CTS tests to use tomorrow. If nothing else, I can use a (verbosely requested) subset of webgpu:api,operation,command_buffer,image_copy:undefined_params:*.

…nd buffers

…t::Extent3d`

ErichDonGubler · 2025-10-14T13:04:26Z

I added baseline expectations (plus failures) for webgpu:api,operation,command_buffer,image_copy:undefined_params:* to our CTS list with 932567d. I have amended the current tip of the PR to remove fails-if(dx12) from some of the 2d variants of the added tests, thus proving that we fix something with this PR. Nice!

ErichDonGubler · 2025-10-14T13:18:11Z

cts_runner/test.lst

+webgpu:api,operation,command_buffer,image_copy:undefined_params:initMethod="WriteTexture";checkMethod="FullCopyT2B";dimension="2d"
+webgpu:api,operation,command_buffer,image_copy:undefined_params:initMethod="WriteTexture";checkMethod="FullCopyT2B";dimension="3d"
+webgpu:api,operation,command_buffer,image_copy:undefined_params:initMethod="WriteTexture";checkMethod="PartialCopyT2B";dimension="1d"
+fails-if(dx12) webgpu:api,operation,command_buffer,image_copy:undefined_params:initMethod="WriteTexture";checkMethod="PartialCopyT2B";dimension="2d"


It's odd that webgpu:api,operation,command_buffer,image_copy:undefined_params:initMethod="WriteTexture";checkMethod="PartialCopyT2B";dimension="2d" still fails after this PR's fix. I suspect there's more work to do here to make this correct.

Ah, it seems the full path that's failing is a single subtest exercising a 3rd dimension for the "2d" case: copySize=[3,3,2];origin=["_undef_","_undef_","_undef_"];bytesPerRow=256;rowsPerImage=3

Definitely follow-up work for something more edge-casey. Whew!

…restrictedBufferTextureCopyPitchSupported`

cts_runner/test.lst

ErichDonGubler · 2025-10-14T13:32:32Z

CHANGELOG.md

+#### DX12
+
+- Align copies b/w textures and buffers via a single intermediate buffer per copy when `D3D12_FEATURE_DATA_D3D12_OPTIONS13.UnrestrictedBufferTextureCopyPitchSupported` is `false`. By @ErichDonGubler in [#7721](https://github.com/gfx-rs/wgpu/pull/7721).
+


onuts, I almost forgot to move this out of the previous release section.

@cwfitzgerald: I'm strongly considering experimenting with adding some CI that fails a PR that adds things to the CHANGELOG outside of the Unreleased section, unless opted out by a label. Thoughts?

I guess we don't have to make it a required check, either. It can simply be a signal that something might be wrong, at first.

torokati44 · 2025-10-14T13:45:56Z

Oh, is a backport of this to the 25/26/27 series, and corresponding patch releases feasible? 👀 It certainly would be appreciated IMHO!

ErichDonGubler · 2025-10-16T15:36:47Z

@torokati44: Two things:

For optional fixes like this, we generally expect the community to handle backporting effort (which should be light here, since you can omit the test coverage). So, if you're willing, then we look forward to a PR from you against v26 and v27. 😄
In our maintainers' meeting today, we know we're willing to field backports to v26 (esp. for Bevy) and v27. Was there a reason you wanted to backport to v25, specifically?

torokati44 · 2025-10-17T16:15:37Z

@ErichDonGubler:

Alright, I'll see what I can do w.r.t backporting PRs.
No, not really, anymore, since chore: Update wgpu to 26, egui to match ruffle-rs/ruffle#21730 got merged (but not yet chore: Update wgpu to 27, egui to 0.33 ruffle-rs/ruffle#21895)

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from 612dc54 to 60d2d96 Compare May 24, 2025 13:13

jimblandy mentioned this pull request Jun 3, 2025

Direct3D buffer-to-texture copies don't need a temporary buffer #7748

Open

This comment was marked as resolved.

Sign in to view

ErichDonGubler marked this pull request as ready for review June 13, 2025 07:50

ErichDonGubler requested a review from a team as a code owner June 13, 2025 07:50

ErichDonGubler commented Jun 13, 2025

View reviewed changes

wgpu-hal/src/dx12/mod.rs Outdated Show resolved Hide resolved

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from 60d2d96 to 505438d Compare June 13, 2025 07:53

This comment was marked as resolved.

Sign in to view

cwfitzgerald assigned teoxoy Jun 18, 2025

andyleiserson mentioned this pull request Jul 15, 2025

wgpu does not honor platform alignment requirements on texture-buffer copies when they are stricter than WebGPU #7946

Open

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from 505438d to 734e1a3 Compare July 23, 2025 19:55

This comment was marked as resolved.

Sign in to view

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch 3 times, most recently from 335c9ab to fd850ff Compare July 25, 2025 21:16

teoxoy requested changes Jul 28, 2025

View reviewed changes

wgpu-hal/src/dx12/command.rs Outdated Show resolved Hide resolved

wgpu-hal/src/dx12/command.rs Outdated Show resolved Hide resolved

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from fd850ff to 5fa4092 Compare July 29, 2025 02:09

ErichDonGubler mentioned this pull request Jul 30, 2025

[d3d12] Support padded rows_per_image for 3D texture writes #4150

Open

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from 5fa4092 to 698316c Compare August 6, 2025 00:48

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from 698316c to 275ec2f Compare October 8, 2025 21:10

ErichDonGubler requested a review from teoxoy October 9, 2025 01:13

teoxoy approved these changes Oct 13, 2025

View reviewed changes

ErichDonGubler added 4 commits October 13, 2025 17:43

refactor(dx12): detect UnrestrictedBufferTextureCopyPitchSupported

d056472

refactor(dx12): lower list extraction for copies between textures a…

5b6ebef

…nd buffers

refactor(hal): impl. From conversions b/w wgh::CopyExtent and `wg…

c9f6a3e

…t::Extent3d`

refactor(dx12): extract copy_aligned in copy_texture_to_buffer

75e6e36

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch 3 times, most recently from 67c8472 to 78798fe Compare October 13, 2025 22:26

test(cts): add …,image_copy:undefined_params:* with current failures

932567d

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch 2 times, most recently from a78375d to 3f65b82 Compare October 14, 2025 12:59

ErichDonGubler commented Oct 14, 2025

View reviewed changes

fix(dx12): align tex. <-> buf. copies via intermediate buffer if `!Un…

20d31b6

…restrictedBufferTextureCopyPitchSupported`

ErichDonGubler force-pushed the dx12-aligned-texbuf-copy-offset branch from 3f65b82 to 20d31b6 Compare October 14, 2025 13:28

ErichDonGubler enabled auto-merge (rebase) October 14, 2025 13:28

ErichDonGubler commented Oct 14, 2025

View reviewed changes

cts_runner/test.lst Show resolved Hide resolved

ErichDonGubler commented Oct 14, 2025

View reviewed changes

ErichDonGubler merged commit 54ded60 into gfx-rs:trunk Oct 14, 2025
41 checks passed

ErichDonGubler deleted the dx12-aligned-texbuf-copy-offset branch October 14, 2025 13:39

torokati44 mentioned this pull request Oct 18, 2025

Backport #7721 to v27 #8374

Merged

		#### DX12

		- Align copies b/w textures and buffers via a single intermediate buffer per copy when `D3D12_FEATURE_DATA_D3D12_OPTIONS13.UnrestrictedBufferTextureCopyPitchSupported` is `false`. By @ErichDonGubler in [#7721](https://github.com/gfx-rs/wgpu/pull/7721).

Conversation

ErichDonGubler commented May 23, 2025 • edited by teoxoy Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

This comment was marked as resolved.

Uh oh!

This comment was marked as resolved.

This comment was marked as resolved.

This comment was marked as resolved.

ErichDonGubler commented Jul 24, 2025

Uh oh!

teoxoy left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

ErichDonGubler commented Oct 9, 2025

Uh oh!

ErichDonGubler commented Oct 9, 2025

Uh oh!

ErichDonGubler commented Oct 14, 2025

Uh oh!

ErichDonGubler Oct 14, 2025

Choose a reason for hiding this comment

Uh oh!

ErichDonGubler Oct 14, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

ErichDonGubler Oct 14, 2025

Choose a reason for hiding this comment

Uh oh!

ErichDonGubler Oct 14, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

torokati44 commented Oct 14, 2025

Uh oh!

ErichDonGubler commented Oct 16, 2025

Uh oh!

torokati44 commented Oct 17, 2025

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

ErichDonGubler commented May 23, 2025 •

edited by teoxoy

Loading