Bug 214392

Summary:	[WebGL2] tex-srgb-mipmap test fails on macOS Intel + iOS (but passes on macOS Apple Silicon)
Product:	WebKit	Reporter:	Dean Jackson <dino>
Component:	WebGL	Assignee:	Kimmo Kinnunen <kkinnunen>
Status:	ASSIGNED ---
Severity:	Normal	CC:	dino, jdarpinian, justin_fan, kbr, kkinnunen, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=229955
Bug Depends on:	223934
Bug Blocks:

Description Dean Jackson 2020-07-15 19:48:00 PDT

The test webgl/2.0.0/conformance2/textures/misc/tex-srgb-mipmap.html is failing on:

- macOS Intel (AMD) (didn't check Intel)
- iOS (hardware)

But passing on:

- macOS Apple Silicon

It also has different results on iOS Simulator (still failing, just different pixel colour values)

Comment 1 Radar WebKit Bug Importer 2020-07-15 19:48:15 PDT

<rdar://problem/65641438>

Comment 2 Kenneth Russell 2020-07-16 12:49:24 PDT

Comparing the results of the 2.0.0 snapshot:
https://www.khronos.org/registry/webgl/conformance-suites/2.0.0/conformance2/textures/misc/tex-srgb-mipmap.html

to top-of-tree:
https://www.khronos.org/registry/webgl/sdk/tests/conformance2/textures/misc/tex-srgb-mipmap.html

the 2.0.0 version fails in Chrome Canary on macOS but the top-of-tree version passes.

If I remember correctly, Intel contributed this test and workarounds for driver bugs where mipmaps for sRGB textures weren't generated correctly.

I've just filed:

Workarounds for sRGB mipmap generation needed on macOS
https://bugs.chromium.org/p/angleproject/issues/detail?id=4848

about this.

Khronos' 2.0.0 snapshot of this test also needs to be updated, and rolled forward in WebKit too.