Thanks so much for doing that. LGTM1
On Wednesday, September 3, 2025 at 7:49:21 PM UTC+1 Brandon Jones wrote: > Hey Alex! > > An updated explainer is now hosted at > https://github.com/gpuweb/gpuweb/blob/main/proposals/primitive-index.md. > It's still fairly brief because this is a relatively small feature. > > --Brandon > > On Wed, Sep 3, 2025 at 7:13 AM Alex Russell <slightly...@chromium.org> > wrote: > >> Thanks for this, Brandon. >> >> As you know, the collateral we need to go first is much higher than when >> closing compatibility gaps. >> >> This explainer doesn't indicate why anyone needs the feature, show the >> before/after state of example code, or discuss considered alternatives. I'm >> inclined to support the feature, but can't without more to go on. Can you >> produce and updated explainer with the various things we usually expect to >> see? >> >> Best, >> >> Alex >> On Wednesday, August 27, 2025 at 7:17:40 PM UTC+1 Brandon Jones wrote: >> >>> Apologies! We're currently trying to decide where docs like that should >>> live after we move them out of experimental status. In the meantime you can >>> see the historical copy of the explainer here: >>> https://dawn.googlesource.com/dawn/+/2819d509eff7e314e5ebce15cc3a7cb13370a505/docs/tint/extensions/chromium_experimental_primitive_id.md >>> >>> (Note that at the time the explainer was written the feature was going >>> to be named primitive_id, the rename to primitive_index was a relatively >>> late change by the working group.) >>> >>> --Brandon >>> >>> On Wed, Aug 27, 2025 at 1:02 AM Daniel Bratell <bratel...@gmail.com> >>> wrote: >>> >>>> The Explainer link is a 404 or has restricted access. We need the >>>> explainer to be public. >>>> >>>> /Daniel >>>> On 2025-08-25 10:56, Yoav Weiss (@Shopify) wrote: >>>> >>>> Can you request reviews for security/privacy/etc in chromestatus? >>>> >>>> On Fri, Aug 22, 2025 at 10:16 PM Chromestatus < >>>> ad...@cr-status.appspotmail.com> wrote: >>>> >>>>> Contact emails bajo...@chromium.org >>>>> >>>>> Explainer >>>>> https://dawn.googlesource.com/dawn/+/refs/heads/main/docs/tint/extensions/chromium_experimental_primitive_id.md >>>>> >>>>> >>>>> Specification >>>>> https://gpuweb.github.io/gpuweb/#dom-gpufeaturename-primitive-index >>>>> >>>>> Summary >>>>> >>>>> This feature adds a new optional capability to WebGPU that exposes a >>>>> new WGSL shader builtin, 'primitive_index'. This builtin provides a >>>>> per-primitive index to fragment shaders on supported hardware, similar to >>>>> the existing vertex_index and instance_index builtins. The primitive >>>>> index >>>>> is useful for advanced graphical techniques, such as virtualized geometry. >>>>> >>>>> >>>>> Blink component Blink>WebGPU >>>>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWebGPU%22> >>>>> >>>>> >>>>> Search tags webgpu <http:///features#tags:webgpu>, primitive >>>>> <http:///features#tags:primitive> >>>>> >>>>> TAG review None >>>>> >>>>> TAG review status Pending >>>>> >>>>> Risks >>>>> >>>>> >>>>> Interoperability and Compatibility >>>>> >>>>> Little to none. It's a fairly minor feature that all implementors have >>>>> voiced support for. The feature is optional and support for it must be >>>>> explicitly queried through the standard WebGPU supported features >>>>> mechanism. Some hardware doesn't expose it yet, so developers need to >>>>> structure their apps to have a fallback path anyway. >>>>> >>>>> >>>>> *Gecko*: No signal >>>>> >>>>> *WebKit*: No signal >>>>> >>>>> *Web developers*: No signals >>>>> >>>>> *Other signals*: >>>>> >>>>> Ergonomics >>>>> >>>>> None. >>>>> >>>>> >>>>> Activation >>>>> >>>>> None. >>>>> >>>>> >>>>> Security >>>>> >>>>> None. >>>>> >>>>> >>>>> 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? >>>>> >>>>> None >>>>> >>>>> >>>>> Debuggability >>>>> >>>>> WGSL shader feature. Shaders generally lack debugging support in >>>>> browsers. >>>>> >>>>> >>>>> Will this feature be supported on all six Blink platforms (Windows, >>>>> Mac, Linux, ChromeOS, Android, and Android WebView)? Yes >>>>> >>>>> Feature is widely supported and has equivalents in all Native APIs >>>>> that WebGPU is implemented on top of. Some older hardware lacks ability >>>>> to >>>>> report the value, which is why it's an optional feature. >>>>> >>>>> >>>>> Is this feature fully tested by web-platform-tests >>>>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> >>>>> ? No >>>>> >>>>> WebGPU CTS tests are a WIP: https://github.com/gpuweb/cts/pull/4435 >>>>> >>>>> >>>>> Flag name on about://flags enable-unsafe-webgpu >>>>> >>>>> Finch feature name None >>>>> >>>>> Non-finch justification None >>>>> >>>>> Rollout plan Will ship enabled for all users >>>>> >>>>> Requires code in //chrome? False >>>>> >>>>> Tracking bug https://issues.chromium.org/issues/342172182 >>>>> >>>>> 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). >>>>> None >>>>> >>>>> Link to entry on the Chrome Platform Status >>>>> https://chromestatus.com/feature/6467722716250112?gate=4665168428662784 >>>>> >>>>> This intent message was generated by Chrome Platform Status >>>>> <https://chromestatus.com>. >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "blink-dev" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to blink-dev+unsubscr...@chromium.org. >>>>> To view this discussion visit >>>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68a8d032.050a0220.8fac8.a218.GAE%40google.com >>>>> >>>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/68a8d032.050a0220.8fac8.a218.GAE%40google.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "blink-dev" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to blink-dev+unsubscr...@chromium.org. >>>> To view this discussion visit >>>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohS%2BP74WaABq%2BdYeukKDUvBazGrTk7SnT5QLRj09ZZwrE1w%40mail.gmail.com >>>> >>>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAOmohS%2BP74WaABq%2BdYeukKDUvBazGrTk7SnT5QLRj09ZZwrE1w%40mail.gmail.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>>> -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+unsubscr...@chromium.org. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/479b3a9c-ade3-470f-be1b-4b948f85ee8an%40chromium.org.
