RESOLVED CONFIGURATION CHANGED238135
REGRESSION (Safari 15.4): WebGL canvas suddenly turns black 
https://bugs.webkit.org/show_bug.cgi?id=238135
Summary REGRESSION (Safari 15.4): WebGL canvas suddenly turns black
Daniel Balog
Reported 2022-03-21 00:58:04 PDT
The application at the following URL: https://dev.luciad.com/portal/packed-samples/panoramics/panorama/index.html?webgl&reference=epsg:4978 Seems to be broken since the new Safari 15.4 upgrade, as far as I can tell. If you open this page, and move the mouse around a bit, the screen will go black. There's no clear errors on the console. I'm not sure how to debug this. You can temporarily "fix" the application by resizing the window. But moving the mouse will cause it to turn black again. In Chrome and Edge, the application works as intended, even on the same hardware. I'm running an M1 MacBook Pro with all the latest software updates.
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Daniel Balog
Comment 1 2022-03-21 05:31:51 PDT
Further feedback: I can't reproduce this on a 2017 Intel-based MacBook Pro with Safari 15.4. This device uses an AMD discrete GPU. On this device, the web app works as intended and produces results similar to Chrome. I can however reproduce something similar on an M1 iPad Air, so it seems to be related to the M1 chip and webkit somehow.
Radar WebKit Bug Importer
Comment 2 2022-03-21 09:25:11 PDT
<rdar://problem/90572515>
Kenneth Russell
Comment 3 2022-03-22 12:07:06 PDT
This will definitely be fixed with the forthcoming roll to top-of-tree ANGLE in Bug 238171; it's possible it's already rendering correctly in top-of-tree WebKit with other cherry-picked fixes. Just verified in the MiniBrowser with a local build of WebKit + that ANGLE roll.
Daniel Balog
Comment 4 2022-03-22 23:55:47 PDT
That's great news. Thank you Kenneth.
Anna from Mapbox
Comment 5 2022-03-30 00:54:27 PDT
Hey Kenneth! I reported https://bugs.webkit.org/show_bug.cgi?id=237918, which fixes the webgl bug in iOS. However, we also experience this bug in M1 macs. Can you confirm whether the fix for this bug report fixes our example for M1 macbooks? We are still seeing the bug for M1 Macs in Safari Technology Preview 142. Here's the jsbin again: https://jsbin.com/mojuyosenu/edit?html,css,js,output I'll open a new bug report if this isn't already resolved. Thanks so much!
Kenneth Russell
Comment 6 2022-03-30 11:15:50 PDT
Yes, I just confirmed with a debug build of top-of-tree WebKit from today running in the Minibrowser on an M1 Mac that the flickering problem is fixed with: https://jsbin.com/mojuyosenu/edit?html,css,js,output
Alexey Proskuryakov
Comment 7 2022-06-22 13:53:25 PDT
Bug 238171 has been fixed for a while, so marking this as Configuration Changed.
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