Bug 100703

Summary:	stroke-miterlimit is operating in device space
Product:	cairo	Reporter:	Aidan Kane <aidankane>
Component:	image backend	Assignee:	Chris Wilson <chris>
Status:	RESOLVED MOVED	QA Contact:	cairo-bugs mailing list <cairo-bugs>
Severity:	normal
Priority:	medium	CC:	aidankane
Version:	1.12.16
Hardware:	Other
OS:	All
Whiteboard:
i915 platform:		i915 features:
Attachments:	test case Wrong - before patch Right - after patch patch

Description Aidan Kane 2017-04-17 23:01:38 UTC

When applying the stroke-miterlimit, cairo is using the slopes of the lines after transformations are applied to figure out when to switch to bevel.

I've patched this in cairo-path-stroke-polygon.c to fix it and to make it consistent with the way cairo-path-stroke-traps.c, cairo-path-stroke-tristrip.c and cairo-path-stroke.c all do it.

Finally, I'm a) not a C guy and b) don't really know the cairo code so forgive me if any of this is off the mark!

I've attached an example with the bottom 2 line un-transformed, and the top 2 being squashed.

Comment 1 Aidan Kane 2017-04-17 23:02:36 UTC

Created attachment 130881 [details]
test case

Comment 2 Aidan Kane 2017-04-17 23:03:08 UTC

Created attachment 130882 [details]
Wrong - before patch

Comment 3 Aidan Kane 2017-04-17 23:03:37 UTC

Created attachment 130883 [details]
Right - after patch

Comment 4 Aidan Kane 2017-04-17 23:04:19 UTC

Created attachment 130884 [details] [review]
patch

Comment 5 GitLab Migration User 2018-08-25 13:47:29 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/196.

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