Bug 218595

Summary:	Allow non-power-of-two mipmapped compressed textures with WEBGL_compressed_texture_s3tc
Product:	WebKit	Reporter:	Kenneth Russell <kbr>
Component:	WebGL	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	dino, geofflang, jdarpinian, jonahr, kkinnunen, smoley, webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Local Build
Hardware:	Unspecified
OS:	Unspecified

Description Kenneth Russell 2020-11-04 16:52:24 PST

In https://github.com/KhronosGroup/WebGL/issues/3117 the implementation of the WEBGL_compressed_texture_s3tc extension in Chromium has been revised to align better with the underlying specifications. Specifically, limited non-power-of-two support has been added, which is portable among all WebGL backends as far back as D3D9.

The test case in related https://github.com/BinomialLLC/basis_universal/issues/158 , http://ahyoomee.miru.hk/basis/demo/threejs.html , is now running correctly in Chrome and Safari, but has regressed in Safari Technology Preview and the ANGLE backend.

The validation of these compressed texture formats needs to be relaxed in order to allow this content to run portably.

Comment 1 Kenneth Russell 2020-11-06 17:40:42 PST

Note that with geofflang's fix in https://bugs.chromium.org/p/angleproject/issues/detail?id=4841 , it's possible that another ANGLE roll into WebKit might implicitly fix this bug.

Comment 2 Radar WebKit Bug Importer 2020-11-09 11:47:31 PST

<rdar://problem/71202732>