239688 2022-04-23 00:03:00 -0700 REGRESSION (iOS 15.4): ColorizePhoto.com doesn't work 2024-08-27 00:13:43 -0700 1 1 1 Unclassified WebKit WebGL Safari 15 iPhone / iPad iOS 15 RESOLVED WONTFIX https://bugs.webkit.org/show_bug.cgi?id=240790 InRadar P2 Major --- 231180 1 nkronlage webkit-unassigned dino kbr kkinnunen webkit-bug-importer oldest_to_newest 1863869 0 nkronlage 2022-04-23 00:03:00 -0700 A recent regression in iOS 15.4 causes https://www.colorizephoto.com/ to stop working, affecting many site users. Disabling WebGL via Metal restores functionality to the site. Repro: Ensure 'WebGL via Metal' enabled: Settings App -> Safari -> Advanced -> Experimental Features -> Turn on 'WebGL via Metal' In Safari, go to https://www.colorizephoto.com/converter Try painting on Clint Eastwood's face Expected: The black/white photo should have skin color where you paint Actual: Nothing happens - no coloring of the black/white photo Try again after turning off 'WebGL via Metal' to see the correct behavior 1863981 1 webkit-bug-importer 2022-04-24 13:02:57 -0700 <rdar://problem/92238140> 1871120 2 kkinnunen 2022-05-23 03:44:09 -0700 Still repros on iOS. Unclear if bug 240790 is the root cause 2055544 3 kkinnunen 2024-08-27 00:12:18 -0700 This does not work on iOS devices as it uses 32-bit float blending via EXT_float_blend It should implement fallback for devices not supporting these via https://registry.khronos.org/webgl/extensions/EXT_color_buffer_half_float 2055545 4 kkinnunen 2024-08-27 00:13:43 -0700 It is unclear if the GL backend blended incorrectly or if it was able to use some non-generic configuration that allowed blending.