RESOLVED INVALID 100719
[Qt] Rendering a scaled canvas with shadowBlur is incorrect and really slow 
https://bugs.webkit.org/show_bug.cgi?id=100719
Summary [Qt] Rendering a scaled canvas with shadowBlur is incorrect and really slow
evan.exe
Reported 2012-10-29 18:44:17 PDT
Created attachment 171357 [details] Screenshot and demo C++ Qt project OS X version: 10.8.2 Qt version: 4.8.1 Load shadow-blur-test.html in a QWebView. It renders two identical red squares with a drop shadow. The left square has a scale of 1 and the right square has a scale of 0.01. Expected: Both the left and right renderings should look the same. Instead: The left rendering is rendered correctly but the right rendering only has a drop shadow along the vertical edges. In addition, rendering the right square takes 13 seconds vs 1 millisecond for the left square. It seems that QtWebKit renders the shadow at a huge resolution and then downsamples afterwards. Workaround: Don't use the canvas transform API and do all transforms manually instead.
Attachments
Screenshot and demo C++ Qt project (22.38 KB, application/zip)
2012-10-29 18:44 PDT, evan.exe 		no flags
Details
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Jocelyn Turcotte
Comment 1 2014-02-03 03:23:07 PST
=== Bulk closing of Qt bugs === If you believe that this bug report is still relevant for a non-Qt port of webkit.org, please re-open it and remove [Qt] from the summary. If you believe that this is still an important QtWebKit bug, please fill a new report at https://bugreports.qt-project.org and add a link to this issue. See http://qt-project.org/wiki/ReportingBugsInQt for additional guidelines.
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