LGTM2
/Daniel
On 2026-08-26 12:21, Yoav Weiss (@Shopify) wrote:
LGTM1
On Wednesday, August 26, 2026 at 10:02:53 AM UTC+2 [email protected]
wrote:
FWIW as developers of the browser game engine Construct
(https://www.construct.net/) we want this to be able to optimize
3D rendering in WebGPU. We already use EXT_conservative_depth in
the WebGL renderer where available, and this brings the same
feature to WebGPU.
Ashley
On Tue, 25 Aug 2026 at 04:14, 'dan sinclair' via blink-dev
<[email protected]> wrote:
There are signals, but indirectly. Developers have requested
having access to early-z-test
(https://github.com/gpuweb/gpuweb/issues/4891#issuecomment-3341897141
<https://github.com/gpuweb/gpuweb/issues/4891#issuecomment-3341897141>).
But, if you write to the `frag_depth` it will disable the
early-z test. Adding the `less` or `greater` attribute allows
the fragment shader to write to the fragment depth, while
maintaining the early-z optimization because the shader knows
you're only writing in the depth in a given direction.
So, while developers did not specifically comment on this, it
is a component of providing a comprehensive early-z feature in
the future.
dan
On Mon, Aug 24, 2026 at 2:54 PM Alex Russell
<[email protected]> wrote:
Are there really no signals from developers? Is nobody
asking for this?
On Monday, August 24, 2026 at 9:03:33 AM UTC-7
Chromestatus wrote:
*Contact emails*
[email protected]
*Explainer*
https://github.com/gpuweb/gpuweb/blob/main/proposals/fragment-depth.md
<https://github.com/gpuweb/gpuweb/blob/main/proposals/fragment-depth.md>
*Specification*
https://github.com/gpuweb/gpuweb/pull/6299
<https://github.com/gpuweb/gpuweb/pull/6299>
*Summary*
Adds the ability to provide a `less` or `greater`
modifier to the `@builtin(frag_depth)` in WGSL. The
current `@builtin(frag_depth)` can potentially
introduce a performance penalty due to disabling the
early-Z optimizations on a draw call. The new
modifiers allow the explicit setting of the buffer
mode and allow the early-Z optimizations to be applied.
*Blink component*
Blink>WebGPU
<https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWebGPU%22>
*Web Feature ID*
webgpu <https://webstatus.dev/features/webgpu>
*Motivation*
In the current WGSL specification, the mere act of
writing to @builtin(frag_depth) often incurs a
significant performance penalty because driver
heuristics cannot guarantee that the fragment shader
output will adhere to the depth written by the
rasterizer's interpolated depth. Consequently, writing
to frag_depth typically forces the GPU to disable
crucial early-Z optimizations for the entire draw
call. The introduction of a new depth_mode built-in
parameter for the @builtin(frag_depth) with modes
less, and greater directly addressing this performance
limitation by letting the developer express their
intent to the hardware.
*Initial public proposal*
https://github.com/gpuweb/gpuweb/blob/main/proposals/fragment-depth.md
<https://github.com/gpuweb/gpuweb/blob/main/proposals/fragment-depth.md>
*TAG review*
/No information provided/
*TAG review status*
Pending
*Goals for experimentation*
None
*Risks*
*Interoperability and Compatibility*
This feature has been approved in W3C GPU for the Web
WG meetings including participants from Safari and
Firefox.
/Gecko/: No
signal (https://github.com/gpuweb/gpuweb/pull/6299
<https://github.com/gpuweb/gpuweb/pull/6299>) Feedback
indicated via WebGPU standardization process.
/WebKit/:
Positive (https://github.com/gpuweb/gpuweb/pull/6299
<https://github.com/gpuweb/gpuweb/pull/6299>)
Specification approval constitutes a positive signal,
per
https://github.com/WebKit/standards-positions/issues/294#issuecomment-1877411933
<https://github.com/WebKit/standards-positions/issues/294#issuecomment-1877411933>
/Web developers/: No signals
/Other signals/:
*WebView application risks*
Does this intent deprecate or change behavior of
existing APIs, such that it has potentially high risk
for Android WebView-based applications?
/No information provided/
*Debuggability*
/No information provided/
*Will this feature be supported on all six Blink
platforms (Windows, Mac, Linux, ChromeOS, Android, and
Android WebView)?*
Yes
All platforms will eventually have support. Will
immediately be available on Android, Android WebView,
ChromeOS, Mac, and Windows, where hardware support is
available. Linux is planned to have WebGPU support in
the future, so this feature will become available when
WebGPU does.
*Is this feature fully tested by web-platform-tests
<https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?*
Yes
WebGPU/WGSL have a conformance test suite
(https://github.com/gpuweb/cts) that is regularly
pulled into Chromium and part of the testing of
Dawn/Tint in Chromium. While the CTS can be embedded
in WPT, the WebGPU team opted to keep it separate in
Chromium testing to use a customized harness for
robustness and performance. *
https://github.com/gpuweb/cts/pull/4679
<https://github.com/gpuweb/cts/pull/4679> *
https://github.com/gpuweb/cts/pull/4689
<https://github.com/gpuweb/cts/pull/4689>
*Flag name on about://flags*
/No information provided/
*Finch feature name*
WebGPU
*Rollout plan*
Will ship enabled for all users
*Requires code in //chrome?*
False
*Tracking bug*
https://crbug.com/457993779
*Estimated milestones*
No milestones specified
*Anticipated spec changes*
Open questions about a feature may be a source of
future web compat or interop issues. Please list open
issues (e.g. links to known github issues in the
project for the feature specification) whose
resolution may introduce web compat/interop risk
(e.g., changing to naming or structure of the API in a
non-backward-compatible way).
/No information provided/
*Link to entry on the Chrome Platform Status*
https://chromestatus.com/feature/5663304168112128?gate=5657119415205888
<https://chromestatus.com/feature/5663304168112128?gate=5657119415205888>
This intent message was generated by Chrome Platform
Status <https://chromestatus.com>.
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