Bug 65792

Summary: translateZ(0) causes 'fuzzy' display <img> with SVG source
Product: WebKit Reporter: Michael O'Rourke <mkorourk>
Component: ImagesAssignee: Nobody <webkit-unassigned>
Status: UNCONFIRMED ---    
Severity: Normal CC: ap, simon.fraser, thorton
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: PC   
OS: Windows 7   
Attachments:
Description Flags
Simple example for the bug
none
Lion/Safari5.1
none
Example display in Chrome 13.0.782.107 on Win7-64bit none

Description Michael O'Rourke 2011-08-05 14:51:35 PDT
Created attachment 103118 [details]
Simple example for the bug

The attached zip contains a HTML and SVG file. The HTML includes the SVG content in two separate <img> tags.

The only difference between the two <img> tags is that the second (the right image) has translateZ(0) specified.

This causes a fuzzy display of the image.

The problem does not exist in Firefox 5 or IE 9.
Comment 1 Alexey Proskuryakov 2011-08-06 19:09:28 PDT
Is this limited to text, as in the example? In that case, this looks like a duplicate of bug 23364.
Comment 2 Michael O'Rourke 2011-08-08 09:56:32 PDT
No, this isn't just about text.

In the file, there are two columns. The first (i.e. 'Actual') is live SVG text. The second (i.e. 'Expected') is actually outlines of the text saved as paths in the SVG.

Both columns get incorrectly displayed.
Comment 3 Michael O'Rourke 2011-08-08 09:58:12 PDT
I have some additional information.

This issue seems to be related to subpixel placement. In the HTML file the SVG content is being moved with 'translate(3px, 5.45px)'. If the '5.45' is changed to '5' or '6' then the problem doesn't happen.
Comment 4 Simon Fraser (smfr) 2011-08-08 10:02:02 PDT
The test case is very confusing. Are you using SVG fonts here? And rather than "Actual' and "Expected", please label the columns with what they really are.
Comment 5 Tim Horton 2011-08-08 10:12:52 PDT
Created attachment 103259 [details]
Lion/Safari5.1

Also, can you attach a screenshot of what it looks like for you?
Comment 6 Michael O'Rourke 2011-08-08 10:18:39 PDT
Created attachment 103260 [details]
Example display in Chrome 13.0.782.107 on Win7-64bit