Hi Hazen: I have some really good news.
If you look at http://plplot.sourceforge.net/examples-data/demo28/x28.04.png you will see a weird change in slope in the string near the start of "civilization" and between "software" and "freedom" for these pngcairo results. Revision 10690 fixes this issue and others for example 28 for cairo devices. As a result of this fix, we have good agreement for the first time ever for all pages of this example between the xwin (which uses a much older but historically better debugged code path) and cairo device results! I stumbled on this bug by accident as a side result of attempting to break down some of our coordinate transformations into a series of elementary affine transformations. I was fixing up the documentation of plRotationShear in this regard when I noticed a discrepancy in the code with the new documentation (actually a section of the documentation that didn't have anything to do with the elementary affine transformation representation which is actually beside the point for that code). Anyhow, I am very pleased by this result, and I am sure you will be as well. With all the 3D text stuff we now finally have "at least one foot on dry land" not only with the old code path used by -dev xwin but also the much newer code path used by -dev xcairo. If any other devices give different results than either the xwin or cairo devices for example 28, you can safely conclude those other devices have a bug in their 3D text code path. BTW, why is the shear value returned by plRotationShear the negative of the shear value used in the calculatation of xFormMatrix? I am sure you use that convention consistently (since example 28 is looking good at the moment with cairo devices), but it is certainly a confusing convention when trying to follow the code so you might want to address that issue. Alan __________________________ Alan W. Irwin Astronomical research affiliation with Department of Physics and Astronomy, University of Victoria (astrowww.phys.uvic.ca). Programming affiliations with the FreeEOS equation-of-state implementation for stellar interiors (freeeos.sf.net); PLplot scientific plotting software package (plplot.org); the libLASi project (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); and the Linux Brochure Project (lbproject.sf.net). __________________________ Linux-powered Science __________________________ ------------------------------------------------------------------------------ Join us December 9, 2009 for the Red Hat Virtual Experience, a free event focused on virtualization and cloud computing. Attend in-depth sessions from your desk. Your couch. Anywhere. http://p.sf.net/sfu/redhat-sfdev2dev _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
