Joe Drew (not getting mail) Reporter
	Description • 12 years ago

Go the URL and scratch the image. Before the landing of bug 550309 it was quite fast and smooth; after the landing, it got a bit slower and "chunkier".

Note that, in current nightlies, the demo is *incredibly* slow - this is due to the Ionmonkey landing, and is bug 787892. Turn off Ionmonkey with javascript.options.ion.content = false to reproduce the small slowdown. See bug 787892 comment 10 for more information.

To people triaging the tracking-firefox16 queue: I don't think this necessarily needs to track, but I'll let you make the final call.

	Alex Keybl [:akeybl]
	Comment 1 • 12 years ago

Given where we are in the cycle, and our testing just now, we'll track bug 787892 for FF18 and leave this one untracked/unfixed in FF16 (although we'd take an uplift to FF17 if low risk.

	Boris Zbarsky [:bzbarsky]
	Comment 2 • 12 years ago

> Before the landing of bug 550309 it was quite fast and smooth; after the landing, it got
> a bit slower and "chunkier".

Windows only?  Or also Mac?  I'm not sure I can reproduce it so far (with a current nightly).  But maybe my hardware is just too fast?

	Boris Zbarsky [:bzbarsky]
	Comment 3 • 12 years ago

Looking at profile, there's a good bit of .data getter visible.  That used to be really fast back when it did the wrong thing before bug 550309.  Now it does the wrong thing, but it's slower.  That's covered by bug 746773.

Basically, we can make that part somewhat faster once we can convert ImageData to WebIDL.  Which is right after we drop support for non-WebIDL canvas bindings.  Which is right after we drop support for non-Azure canvas...

We could do an experiment here to see how much perf it wins, if desired.  Joe, if you can reproduce the slowdown, do you want to test the patch?

	Boris Zbarsky [:bzbarsky]
	Comment 4 • 12 years ago

Bug 746773 has been improved a lot.  Is this still a problem?

	Bogdan Maris, Desktop QA
	Comment 5 • 11 years ago

Mozilla/5.0 (Windows NT 5.1; rv:25.0) Gecko/20100101 Firefox/25.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:25.0) Gecko/20100101 Firefox/25.0

Tested on latest Nightly and Firefox 23 (buildID: 20130804030207) beta 10 (buildID: 20130729175331) and the scratching is smooth without glitches.