User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:35.0) Gecko/20100101 Firefox/35.0 Build ID: 20150122214805 Steps to reproduce: Use canvas clearRect() method with a single rectangular clipping area. Actual results: Clearing rectangles with clipping area is much slower than without clipping. Test case: http://jsbin.com/napodinudi Output Firefox: fillRect, no clip: 23ms fillRect, clipped: 21ms clearRect, no clip: 29ms clearRect, clipped: 1545ms Output Chrome: fillRect, no clip: 25ms fillRect, clipped: 17ms clearRect, no clip: 23ms clearRect, clipped: 22ms Expected results: Clearing rectangles should work as fast as without clipping.
Thanks for the report and for the testcase! I can't reproduce on Mac, and this looks like it might be OS/graphic-driver specific. Could you copy the data from the Graphics section of about:support <https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox> here and also look up the graphics driver version? Also it might be worth re-testing with the most recent pre-release version <https://nightly.mozilla.org/>, first creating a new Firefox profile <https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles#w_creating-a-profile>.
Using latest release (FF 36.0.4), latest graphics driver. Can still reproduce. Maybe Windows only? Graphics info: Direct2D aktiviert true DirectWrite aktiviert true (6.2.9200.16571) Geräte-ID 0x0fd4 GPU #2 aktiv false GPU-beschleunigte Fenster 1/1 Direct3D 11 (OMTC) Karten-Beschreibung NVIDIA GeForce GTX 660M Karten-RAM 2048 Karten-Treiber nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Subsys-ID 21151043 Treiber-Datum 3-13-2015 Treiber-Version 220.127.116.1188 Vendor-ID 0x10de WebGL-Renderer Google Inc. -- ANGLE (NVIDIA GeForce GTX 660M Direct3D9Ex vs_3_0 ps_3_0) windowLayerManagerRemote true AzureCanvasBackend direct2d AzureContentBackend direct2d AzureFallbackCanvasBackend cairo AzureSkiaAccelerated 0
Results with Nightly 40.0a1: fillRect, no clip: 13ms fillRect, clipped: 13ms clearRect, no clip: 17ms clearRect, clipped: 695ms
Is this still an issue?
Well, just try it out. Link to test case has been given in the initial report. http://jsbin.com/napodinudi Results with FF 41.0.1: fillRect, no clip: 14ms fillRect, clipped: 13ms clearRect, no clip: 23ms clearRect, clipped: 511ms So, yes, still an issue.
It looks like things improved for you between Firefox 35 and 41. I've tested this locally on my Macbook Pro and I confirm the issue but I think I've also found a regression. Results after 10 testruns: > Chrome 45 scores 42ms over 10 testruns > Firefox 24 scores 127ms over 10 testruns [202% worse than Chrome] > Firefox 40 scores 537ms over 10 testruns [1179% worse than Chrome, 323% worse than Firefox 24] > Firefox 44 scores 561ms over 10 testruns [1236% worse than Chrome, 342% worse than Firefox 44] At the very least I'm marking the bug as confirmed. However we probably need to investigate the major perf regression before we can begin to look at competitiveness.
(In reply to Anthony Hughes, QA Mentor (:ashughes) from comment #6) > > Firefox 44 scores 561ms over 10 testruns [1236% worse than Chrome, 342% worse than Firefox 44] (Typo: this should read '342% worse than Firefox 24')