Bug 10036

Summary:	nquartz surface does not scale line widths
Product:	cairo	Reporter:	Brian Ewins <Brian.Ewins>
Component:	quartz backend	Assignee:	Carl Worth <cworth>
Status:	RESOLVED FIXED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	medium	CC:	hugo.vincent
Version:	1.3.15
Hardware:	Other
OS:	Mac OS X (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	patch fixing the problem in a minimalist way. updated patch. updated patch after nquartz renamed to quartz. fixes patch up to pass text-rotate test reverting to a previous version of patch after bugfix

Description Brian Ewins 2007-02-19 18:14:20 UTC

(this is against nquartz, not quartz, but theres no component yet)

The bug is easy to reproduce - just run the line-width-scale test. Apparently this bug is biting the Joost folks. 

The reason for the bug is that line width scaling is done in cairo-path-stroke.c, not used in nquartz, while all of the points used in paths are scaled in cairo-gstate. 

A patch follows which undoes the point scaling then draws the paths applying the scale to the CGContext. However some paths that hit this code don't provide the matrices required. A better fix (?) might be to store the points in the path in user space, at least for nquartz. I'm not proposing that here as its much more disruptive.

Comment 1 Brian Ewins 2007-02-19 18:18:47 UTC

Created attachment 8781 [details] [review]
patch fixing the problem in a minimalist way.

This makes a couple of tests pass, but the code paths where I use the identity matrix look super-suspicious; I can't fix those without much larger changes, but then, I don't know what tests they cause to fail (if any).

Comment 2 Brian Ewins 2007-02-20 09:35:01 UTC

It seems that a very similar patch was already reviewed and applied to the pdf surface backend:
http://lists.freedesktop.org/archives/cairo/2006-April/006740.html
this commit:
http://gitweb.freedesktop.org/?p=cairo;a=commit;h=8d635a3aa967b16de5047eceadf3d350d1169a76

Since Carl ok'd that patch, this one can't be as bad as I thought :) I'll massage it into the same shape (nulls instead of identity matrices, consistent names, etc) and push that tonight if Vlad gives it the ok.

Comment 3 Brian Ewins 2007-02-20 17:53:06 UTC

Created attachment 8795 [details] [review]
updated patch.

This patch is more like the one applied to the pdf surface, and is updated now that the nquartz surface has been renamed.

Comment 4 Brian Ewins 2007-03-06 16:17:45 UTC

Created attachment 9001 [details] [review]
updated patch after nquartz renamed to quartz.

this is the same patch as before, just brought up to date again.

Comment 5 Hugo Vincent 2007-03-16 18:36:37 UTC

*** Bug 10141 has been marked as a duplicate of this bug. ***

Comment 6 Brian Ewins 2007-03-25 10:25:34 UTC

Created attachment 9282 [details] [review]
fixes patch up to pass text-rotate test

The previous version of the patch produced incorrect results when the ctm contained rotation, eg the text-rotate test. This version fixes that up. The only test still looking odd is skew-extreme, which now has lines with the correct widths but apparently incorrect offsets.

Comment 7 Brian Ewins 2007-03-25 14:49:28 UTC

Created attachment 9292 [details] [review]
reverting to a previous version of patch after bugfix

The reason why the original patch messed up on rotation/skew was due to a typo elsewhere in the code, fixed in commit c8e37af4b06fffe1aa1a1c3d2cd6481cc2cf8938.

With this patch quartz now passes the line-width, line-width-scaled and skew-extreme tests.

Comment 8 Brian Ewins 2007-11-15 10:17:32 UTC

This was fixed back in March.

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