[cairo] Problem with unaligned clip regions

Tristan Schmelcher tschmelcher at google.com
Wed Mar 16 18:39:07 PDT 2011


I am building a cairo app and I have come across what seems to be a
bug in the handling of unaligned clip regions. When painting from one
image surface to another image surface with a complex clip region
involving unaligned boxes, cairo/pixman paints a large black rectangle
to the target in an area that is not supposed to be modified. The
issue repros for me 100% of the time with cairo 1.10.2 and pixman
0.20.2 (and also pixman 0.21.4). It does NOT occur with 1.8.10 /
0.16.4. I've attached a minimal test program that repros the problem.

I'm going to work around the problem in my app by avoiding unaligned
clip regions so I don't really need it to be fixed, but I figured
people would probably still want to know about it. :)
-------------- next part --------------
A non-text attachment was scrubbed...
Name: test.c
Type: text/x-csrc
Size: 2050 bytes
Desc: not available
URL: <http://lists.cairographics.org/archives/cairo/attachments/20110316/dc3bd325/attachment.c>

More information about the cairo mailing list