Bug 210524

Summary:

OES_texture_float / OES_texture_half_float unavailable in WebGL 1.0 on iOS Simulator with ANGLE

Product:

WebKit

Reporter:

Kenneth Russell <kbr>

Component:

WebGL

Assignee:

Kenneth Russell <kbr>

Status:

RESOLVED FIXED

Severity:

Normal

CC:

dino, ews-watchlist, graouts, jdarpinian, justin_fan, kbr, kondapallykalyan, webkit-bug-importer

Priority:

Keywords:

InRadar

Version:

WebKit Nightly Build

Hardware:

iPhone / iPad

OS:

All

Bug Depends on:

210994, 211971

Bug Blocks:

126404, 207858, 212005, 212170, 212181, 212228

Attachments:

Description	Flags
Logging output	none
Patch	none
Patch	none
Patch	none
Patch	none

Description Kenneth Russell 2020-04-14 16:47:23 PDT

Visiting https://webglreport.com/ on the iOS Simulator with both the current OpenGL ES and the forthcoming ANGLE backend, it appears that OES_texture_float and OES_texture_half_float are supported on the old (non-ANGLE) backend, but not supported on the ANGLE backend.

This might be related indirectly to Chromium bug http://crbug.com/1067122 , where these extensions are not showing up on some other mobile devices, either.

The problem might be overly strict renderability checks than required according to the extension specification - since framebuffer completeness is essentially allowed to fail per specification for almost any reason in OpenGL ES 2.0. In particular, RGB32F and RGB16F textures might not be color-renderable on this hardware, and ANGLE might be requiring them to be in order to expose these extensions.

Comment 1 Kenneth Russell 2020-05-13 23:09:20 PDT

Created attachment 399334 [details]
Logging output

Comment 2 Kenneth Russell 2020-05-13 23:09:35 PDT

Following the logging suggested by Geoff Lang from the ANGLE project in https://bugs.chromium.org/p/angleproject/issues/detail?id=4591 , here are the logs for why OES_texture_float and OES_texture_half_float aren't supported in the iOS Simulator.

OES_texture_float is initially not supported because GL_LUMINANCE_ALPHA32F_EXT isn't texturable, and OES_texture_half_float is not supported because GL_LUMINANCE_ALPHA16F_EXT is not texturable.

Comment 3 Kenneth Russell 2020-05-13 23:17:46 PDT

Filed ANGLE bug https://bugs.chromium.org/p/angleproject/issues/detail?id=4636 about this.

Comment 4 Kenneth Russell 2020-05-14 17:00:10 PDT

Sidestepping the requirement of the texture formats that are supplied by EXT_texture_storage - which iOS doesn't provide - and fixing a bug caused by the fix for Bug 210994, the next issue is that support for luminance/alpha floating-point textures are going to need to be emulated inside ANGLE on top of red/green textures.

Comment 5 Kenneth Russell 2020-05-14 20:40:05 PDT

Created attachment 399451 [details]
Patch

Comment 6 EWS Watchlist 2020-05-14 20:40:40 PDT

Note that there are important steps to take when updating ANGLE. See http://trac.webkit.org/wiki/UpdatingANGLE

Comment 7 Dean Jackson 2020-05-15 14:32:45 PDT

I've checked this on device and it passes the oes-texture-float tests.

Comment 8 Kenneth Russell 2020-05-15 15:44:57 PDT

Created attachment 399521 [details]
Patch

Comment 9 Kenneth Russell 2020-05-15 15:46:00 PDT

Comment on attachment 399521 [details]
Patch

Updating this patch only for testing purposes - not for review or commit. Part of this change is being split off in Bug 211971. The other will likely be landed upstream in ANGLE and then rolled forward into WebKit.

Comment 10 Dean Jackson 2020-05-17 15:51:30 PDT

Unfortunately OES_texture_float_linear will need some work to enable too. ANGLE won't enable that because it believes RGBA32F is not filterable, based on the fact that iOS does not advertise the extension either. Since it is part of core in ES3, it shouldn't need to check for the extension (assuming it is using an ES3 context).

https://bugs.webkit.org/show_bug.cgi?id=212005

Comment 11 Radar WebKit Bug Importer 2020-05-17 15:51:58 PDT

<rdar://problem/63321618>

Comment 12 Justin Fan 2020-05-19 15:28:38 PDT

It appears fast/canvas/webgl/oes-texture-half-float-uint16.html is regressed on ANGLE due to this.

Comment 13 Kenneth Russell 2020-05-20 10:18:16 PDT

Thanks for the heads up Justin. On what platform did you see the regression?

Comment 14 Kenneth Russell 2020-05-20 11:24:39 PDT

Never mind, I see it's on iOS. Blocking Bug 207858.

Comment 15 Kenneth Russell 2020-05-20 12:38:33 PDT

Created attachment 399874 [details]
Patch

Comment 16 Kenneth Russell 2020-05-20 12:50:15 PDT

Comment on attachment 399874 [details]
Patch

Uploaded this latest patch for testing purposes on the bots only. Will pick up this fix by rolling ANGLE forward instead.

Comment 17 Kenneth Russell 2020-05-20 16:03:04 PDT

Comment on attachment 399874 [details]
Patch

Not sure whether my own r- blocked some of the EWS bots from running. Removing it to see.

Comment 18 Kenneth Russell 2020-05-20 16:04:49 PDT

Created attachment 399904 [details]
Patch

Comment 19 Kenneth Russell 2020-05-20 16:05:12 PDT

Clearly I shouldn't have used r- on the earlier patch.

Comment 20 Kenneth Russell 2020-05-20 16:36:08 PDT

Comment on attachment 399904 [details]
Patch

After offline discussion, we've decided to merge this fix directly into WebKit rather than roll ANGLE forward to pick it up. We'll roll ANGLE forward soon and subsume this individual patch.

Requesting review.

Comment 21 EWS 2020-05-20 17:16:51 PDT

Committed r261975: <https://trac.webkit.org/changeset/261975>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 399904 [details].