RESOLVED FIXED 230139
Work around bug 225873 (canvas color space rendering problems) or disable the feature on older OSes 
https://bugs.webkit.org/show_bug.cgi?id=230139
Summary Work around bug 225873 (canvas color space rendering problems) or disable the...
Cameron McCormack (:heycam)
Reported 2021-09-09 17:28:11 PDT
We should be able to work around the framework bug on Apple platforms that caused the canvas rendering problems with different color spaces, identified in bug 225873. The workaround is needed on Big Sur and earlier.
Attachments
Patch (19.19 KB, patch)
2021-09-09 18:24 PDT, Cameron McCormack (:heycam) 		no flags
DetailsFormatted DiffDiff
Patch (19.43 KB, patch)
2021-09-09 23:53 PDT, Cameron McCormack (:heycam) 		no flags
DetailsFormatted DiffDiff
Patch that works around the bug on older OSes (19.96 KB, patch)
2021-09-10 16:03 PDT, Cameron McCormack (:heycam) 		no flags
DetailsFormatted DiffDiff
Timing test (1.74 KB, text/html)
2021-09-10 18:26 PDT, Cameron McCormack (:heycam) 		no flags
Details
Patch for EWS that disables the feature on unsupported platforms (47.79 KB, patch)
2021-09-11 16:44 PDT, Cameron McCormack (:heycam) 		ews-feeder: commit-queue-
DetailsFormatted DiffDiff
Patch for EWS that disables the feature on supported platforms (47.51 KB, patch)
2021-09-11 20:54 PDT, Cameron McCormack (:heycam) 		ews-feeder: commit-queue-
DetailsFormatted DiffDiff
Patch that disables the feature on unsupported platforms (48.03 KB, patch)
2021-09-12 00:14 PDT, Cameron McCormack (:heycam) 		no flags
DetailsFormatted DiffDiff
Patch (48.26 KB, patch)
2021-09-15 22:49 PDT, Cameron McCormack (:heycam) 		no flags
DetailsFormatted DiffDiff
Show Obsolete (6) View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2021-09-09 17:34:18 PDT
<rdar://problem/82951700>
Cameron McCormack (:heycam)
Comment 2 2021-09-09 17:34:59 PDT
I ran Motionmark locally with the workaround in place, and didn't get notably different results.
Cameron McCormack (:heycam)
Comment 3 2021-09-09 17:46:55 PDT
<rdar://81828819>
Cameron McCormack (:heycam)
Comment 4 2021-09-09 18:24:54 PDT
Created attachment 437819 [details] Patch
Cameron McCormack (:heycam)
Comment 5 2021-09-09 23:53:30 PDT
Created attachment 437845 [details] Patch
Cameron McCormack (:heycam)
Comment 6 2021-09-09 23:54:56 PDT
(In reply to Cameron McCormack (:heycam) from comment #2) > I ran Motionmark locally with the workaround in place, and didn't get > notably different results. That is measuring the overhead of doing the color space check, when we don't need to purge the caches. I haven't measured how much it can slow things down when repeatedly switching between color spaces.
Cameron McCormack (:heycam)
Comment 7 2021-09-10 16:03:37 PDT
Created attachment 437918 [details] Patch that works around the bug on older OSes Mark Windows failure since Display P3 canvas is not available there.
Cameron McCormack (:heycam)
Comment 8 2021-09-10 18:25:25 PDT
(In reply to Cameron McCormack (:heycam) from comment #6) > I haven't measured how much it can slow things > down when repeatedly switching between color spaces. I just tested this. The overhead of the context flush and cache purge, when it's needed is about 2 ms on my machine. If drawing operations are done on canvases of alternating color spaces, then this is substantial. So now I am not sure that we want to do this.
Cameron McCormack (:heycam)
Comment 9 2021-09-10 18:26:56 PDT
Created attachment 437934 [details] Timing test This is what I tested with. Got these results: (A and B are srgb canvases, C and D are display-p3 canvases) AAAA: 9 ms CCCC: 23 ms ABAB: 20 ms CDCD: 12 ms ACAC: 42739 ms
Cameron McCormack (:heycam)
Comment 10 2021-09-11 16:44:05 PDT
Created attachment 437970 [details] Patch for EWS that disables the feature on unsupported platforms
Cameron McCormack (:heycam)
Comment 11 2021-09-11 20:54:24 PDT
Created attachment 437978 [details] Patch for EWS that disables the feature on supported platforms
Cameron McCormack (:heycam)
Comment 12 2021-09-12 00:14:02 PDT
Created attachment 437981 [details] Patch that disables the feature on unsupported platforms
EWS
Comment 13 2021-09-15 21:34:00 PDT
Tools/Scripts/svn-apply failed to apply attachment 437981 [details] to trunk. Please resolve the conflicts and upload a new patch.
Cameron McCormack (:heycam)
Comment 14 2021-09-15 22:49:48 PDT
Created attachment 438318 [details] Patch
EWS
Comment 15 2021-09-16 01:57:04 PDT
Committed r282513 (241738@main): <https://commits.webkit.org/241738@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 438318 [details].
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