Re: Cairo Graphics and XQuartz
Re: Cairo Graphics and XQuartz
- Subject: Re: Cairo Graphics and XQuartz
- From: Jennifer Adams <email@hidden>
- Date: Fri, 25 Oct 2013 09:12:40 -0400
I am looking at the list of versions available at http://xquartz.macosforge.org/trac/wiki/Releases
There is a gap between 2.6.3 and 2.7.0.
I installed this one: XQuartz 2.7.0 (xorg-server 1.11.2) and it showed the buggy behavior.
I installed this one: XQuartz 2.6.3 (xorg-server 1.10.3) and everything works perfectly.
--Jennifer
On Oct 24, 2013, at 10:56 PM, Jeremy Huddleston Sequoia wrote:
> Hi Jennifer,
>
> As this is an issue that presents itself when you jump from XQuartz version 2.6.5 to version 2.7.5_rc2, it is likely that it is either a bug in the X11 server. It is possible that a feature added or removed from the server is causing a different codepath to be taken in cairo or your project, so we can't really rule that out completely.
>
> It would be nice to know how versions between 2.6.5 and 2.7.5_rc2 behave.
>
> On Oct 24, 2013, at 18:02, Jennifer Adams <email@hidden> wrote:
>
>> Dear Experts,
>>
>> I am a developer of GrADS, an open-source visualization tool for meteorological data. GrADS is written in C and uses X for its interactive display window. Traditionally, GrADS has had direct calls to the X11 library for the drawing, but we have developed a new interface for the Cairo graphics library to do the X rendering instead.
>>
>> The problem I am having is with Cairo's rendering when using XQuartz. The graphical elements in a simple contour plot are very basic -- nothing but line segments, some with a large number of vertices. Everything looks right when I use the old X11, but if I use XQuartz, I get an incomplete rendering, where only some of the lines are drawn. If I create an X event by moving another xterm window over my X display window and then move it away, the rendering changes -- some more lines are drawn, but only just a few, nothing close to a complete graphic. If I use the traditional version of GrADS (without Cairo), the rendering is normal with both X11 and XQuartz.
>>
>> I wrote a stand-alone short C program (http://iges.org/jma/xdemo.c) to use Cairo to draw a bunch of concentric circles made up of tiny line segments to mimic the GrADS behavior but in a simpler, more portable form. Here are two screen shots that illustrate the problem:
>> http://iges.org/jma/x11.png
>> http://iges.org/jma/xquartz.png
>> This behavior is seen whether I compile and run my stand-alone program on my laptop, or on a remote unix (CentOS) server that I connect to using 'ssh -Y'.
>>
>> It is difficult for me to know whether this is a problem with XQuartz or Cairo … I have posted about this in the Cairo forum and got no helpful response, only some advice to 'move away from X', which is not really a viable option. It feels more like an XQuartz bug, I guess mostly because it works fine with the older X11. Can anybody advise me? I need help! This is a potentially catastrophic problem for our users. When X11 is gone for good, we're hosed if GrADS won't work with XQuartz.
>>
>> Possibly relevant specs:
>> Mac OS X 10.7.5 (it also fails with 10.8, a colleague with a newer laptop tested it for me)
>> XQuartz Version: XQuartz 2.7.5_rc2 (xorg-server 1.13.4)
>> X11 Version: XQuartz 2.6.5 (xorg-server 1.10.6)
>> Cairo version: 1.12.16
>>
>> Thank you!!
>> --Jennifer
>>
>>
>> --
>> Jennifer M. Adams
>> Center for Ocean-Land-Atmosphere Studies (COLA)
>> 111 Research Hall, Mail Stop 2B3
>> George Mason University
>> 4400 University Drive
>> Fairfax, VA 22030
>>
>>
>>
>>
>>
>>
>>
>> --
>> Jennifer M. Adams
>> Center for Ocean-Land-Atmosphere Studies (COLA)
>> 111 Research Hall, Mail Stop 2B3
>> George Mason University
>> 4400 University Drive
>> Fairfax, VA 22030
>>
>>
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>
--
Jennifer M. Adams
Center for Ocean-Land-Atmosphere Studies (COLA)
111 Research Hall, Mail Stop 2B3
George Mason University
4400 University Drive
Fairfax, VA 22030
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