Bug 17448

Summary:	ClearType rendering problem in Firefox
Product:	cairo	Reporter:	Paolo Montrasio <paolo>
Component:	win32 backend	Assignee:	cairo-bugs mailing list <cairo-bugs>
Status:	RESOLVED MOVED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	medium	CC:	bfulgham
Version:	1.7.5
Hardware:	All
OS:	Windows (All)
Whiteboard:
i915 platform:		i915 features:

Description Paolo Montrasio 2008-09-05 04:17:09 UTC

This problem is pretty old so it might be a duplicate but I can't find a bug report for this in the archive. Here's the problem:

Firefox 3 cuts the last line of pixels in text elements that are rendered with opacity < 1.0. A bug has been opened on their bugzilla at https://bugzilla.mozilla.org/show_bug.cgi?id=363861 and there are screenshots and test cases there. It seems that the problem is due to Cairo (I don't know which version, I picked 1.7.5 for opening this bug as it is the default one).

The last comment on the Mozilla bug report links to a thread on your mailing list http://lists.cairographics.org/archives/cairo/2006-October/008081.html
I read the whole of it but it's not clear if the problem has been fixed. It hasn't in the version that Firefox is using now. If it has got fixed you might want to get in touch with the Firefox team and point them to a newer release of your software. You'll make a lot of Firefox users and web application developers happy :-)

Comment 1 Brent Fulgham 2009-12-22 21:56:10 UTC

This bug appears to have been resolved in Firefox around February, 2009.

See https://bugzilla.mozilla.org/show_bug.cgi?id=445087.

They created this patch against Cairo to resolve the problem:
https://bug445087.bugzilla.mozilla.org/attachment.cgi?id=362706

Comment 2 Paolo Montrasio 2009-12-26 01:40:25 UTC

Maybe its not fixed anymore. See comment 82 to the bug at
https://bugzilla.mozilla.org/show_bug.cgi?id=445087#c82

> Jeff Muizelaar [:jrmuizel]      2009-05-25 07:50:44 PDT
> 
> Just a heads up: I accidentally reverted this patch when updating cairo. See
> Bug 494743

Furthermore a user of a browser game of mine just reported that Firefox 3.5 on Windows Vista still has the bug as shown by this image he posted on the game forum: http://img64.imageshack.us/img64/751/senzatitolo1h.gif
The bug is clearly visible in all the 1 characters at the end of the words.

Comment 3 alex.shulgin 2010-06-04 10:15:25 UTC

Hey,

I'm trying to make work the WebKit Win32 cairo port and also affected by the described problem.

Not sure if the patch from Firefox is correct, but it fixes the problem in my case too.

--
Alex

Comment 4 GitLab Migration User 2018-08-25 13:30:49 UTC

-- GitLab Migration Automatic Message --

This bug has been migrated to freedesktop.org's GitLab instance and has been closed from further activity.

You can subscribe and participate further through the new bug through this link to our GitLab instance: https://gitlab.freedesktop.org/cairo/cairo/issues/42.

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.