[Webkit-unassigned] [Bug 237533] iOS/iPad 15.3.1 slow drawElements with TRIANGLE_FAN mode

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=237533

--- Comment #12 from Kimmo Kinnunen <kkinnunen at apple.com> ---
Thanks for continuing to investigate.

I filed upstream ANGLE bug at:
https://bugs.chromium.org/p/angleproject/issues/detail?id=7748

Metal does not support TRIANGLE_FAN drawing mode natively.
ANGLE emulates it.
The GPU implementation of the emulation is turned off when primitive restart is supported. For WebGL2 primitive restart is enabled.

To get an idea of the perf difference after the emulation is fixed to work with primitive restart, you can try to change the test case:
- use WebGL1
or
- change to drawArrays, where the emulation generates the emulated buffer once per draw after modification.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20221011/c3354d51/attachment.htm>