Bug 130153

Summary: Subpixel rendering: Nested layers with subpixel accumulation paint to wrong position.
Product: WebKit Reporter: zalan <zalan>
Component: Layout and RenderingAssignee: zalan <zalan>
Status: RESOLVED FIXED    
Severity: Normal CC: buildbot, commit-queue, esprehn+autocc, glenn, kondapallykalyan, ossy, rniwa, simon.fraser, webkit-ews
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 130199    
Bug Blocks: 130430    
Attachments:
Description Flags
Patch
none
Archive of layout-test-results from webkit-ews-08 for mac-mountainlion
none
Archive of layout-test-results from webkit-ews-15 for mac-mountainlion-wk2
none
Patch
none
Patch none

zalan
Reported 2014-03-12 12:50:53 PDT
Subpixels need to be accumulated through nested layer to calculate correct painting positing.
Attachments
Patch (12.46 KB, patch)
2014-03-12 13:52 PDT, zalan 		no flags
DetailsFormatted DiffDiff
Archive of layout-test-results from webkit-ews-08 for mac-mountainlion (512.17 KB, application/zip)
2014-03-13 19:47 PDT, Build Bot 		no flags
Details
Archive of layout-test-results from webkit-ews-15 for mac-mountainlion-wk2 (515.55 KB, application/zip)
2014-03-13 20:22 PDT, Build Bot 		no flags
Details
Patch (13.94 KB, patch)
2014-03-18 19:13 PDT, zalan 		no flags
DetailsFormatted DiffDiff
Patch (14.76 KB, patch)
2014-03-19 19:16 PDT, zalan 		no flags
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
zalan
Comment 1 2014-03-12 13:52:00 PDT
Created attachment 226551 [details] Patch
Csaba Osztrogonác
Comment 2 2014-03-13 09:43:01 PDT
Comment on attachment 226551 [details] Patch Clearing flags on attachment: 226551 Committed r165540: <http://trac.webkit.org/changeset/165540>
Csaba Osztrogonác
Comment 3 2014-03-13 09:43:08 PDT
All reviewed patches have been landed. Closing bug.
WebKit Commit Bot
Comment 4 2014-03-13 11:42:24 PDT
Re-opened since this is blocked by bug 130199
Build Bot
Comment 5 2014-03-13 19:47:06 PDT
Comment on attachment 226551 [details] Patch Attachment 226551 [details] did not pass mac-ews (mac): Output: http://webkit-queues.appspot.com/results/6741007710289920 New failing tests: compositing/hidpi-absolute-subpixel-positioned-transformed-elements.html
Build Bot
Comment 6 2014-03-13 19:47:11 PDT
Created attachment 226642 [details] Archive of layout-test-results from webkit-ews-08 for mac-mountainlion The attached test failures were seen while running run-webkit-tests on the mac-ews. Bot: webkit-ews-08 Port: mac-mountainlion Platform: Mac OS X 10.8.5
Build Bot
Comment 7 2014-03-13 20:22:09 PDT
Comment on attachment 226551 [details] Patch Attachment 226551 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/4589675771592704 New failing tests: compositing/hidpi-absolute-subpixel-positioned-transformed-elements.html
Build Bot
Comment 8 2014-03-13 20:22:13 PDT
Created attachment 226645 [details] Archive of layout-test-results from webkit-ews-15 for mac-mountainlion-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: webkit-ews-15 Port: mac-mountainlion-wk2 Platform: Mac OS X 10.8.5
zalan
Comment 9 2014-03-18 19:13:56 PDT
Created attachment 227145 [details] Patch
Simon Fraser (smfr)
Comment 10 2014-03-19 16:58:54 PDT
Comment on attachment 227145 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=227145&action=review > Source/WebCore/rendering/RenderLayer.cpp:4176 > + // Translate the graphics context to the snapping position to avoid off-device-pixel positing. This works as long as the user defined > + // transform is not producing subpixel results (translate(0.5px, 0.5px) vs. translate(0.7px, 0.7px)) "This works as long as" isn't really adding information here, and it's not clear what "works" means. I'd remove this second sentence.
zalan
Comment 11 2014-03-19 18:20:51 PDT
(In reply to comment #10) > (From update of attachment 227145 [details]) > View in context: https://bugs.webkit.org/attachment.cgi?id=227145&action=review > > > Source/WebCore/rendering/RenderLayer.cpp:4176 > > + // Translate the graphics context to the snapping position to avoid off-device-pixel positing. This works as long as the user defined > > + // transform is not producing subpixel results (translate(0.5px, 0.5px) vs. translate(0.7px, 0.7px)) > > "This works as long as" isn't really adding information here, and it's not clear what "works" means. I'd remove this second sentence. Indeed. Thanks for the review.
zalan
Comment 12 2014-03-19 19:16:28 PDT
Created attachment 227242 [details] Patch
zalan
Comment 13 2014-03-19 19:16:46 PDT
Comment on attachment 227242 [details] Patch EWS testing.
WebKit Commit Bot
Comment 14 2014-03-20 07:20:53 PDT
Comment on attachment 227242 [details] Patch Clearing flags on attachment: 227242 Committed r165963: <http://trac.webkit.org/changeset/165963>
WebKit Commit Bot
Comment 15 2014-03-20 07:20:59 PDT
All reviewed patches have been landed. Closing bug.
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