Hi Alban: As of revision 9726, we now have alpha channel (opacity) support for the qt device driver. The Qt documentation says QColor actually has 4 channels, with the last one defaulting to completely opaque if you don't specify it which was the mode that you originally implemented. Fortunately, it was easy to change from that completely opaque mode to one that takes advantage of the opacity information supplied by PLplot. The resulting example 30 is much improved (e.g., shows transparency effects) for all the former rasterqt devices (pngqt, jpgqt, etc.) and for qtwidget. Note, we don't expect good-looking results for page 2 of example 30 because we are trying to approximate a gradient with a series of adjacent rectangles. (Someday, PLplot will have proper support for gradients, and this page will look much nicer then.) Spot checking of the remaining examples (all of which use completely opaque colors) showed no issues for the former rasterqt devices and qtwidget.
As a result of my testing of these alpha channel changes, I noticed that epsqt, pdfqt, and svgqt (devices which were not covered by the former rasterqt device) all had problems for filled surfaces, e.g., the solid blocks in example 30 are not filled at all, and the surfaces in example 8 are lace-like (actually a rather cool-looking effect) rather than solid. This issue pre-dates my transparency changes (e.g., it occurs for revision 9725). As you know, these same devices also have problems with segfaults if -fam is not specified which indicates memory management issues for these devices. It is difficult to tell if that is a nasty coincidence or the two issues are related, but it is certainly possible that solution of the memory-management problems for the 3 devices may also sort out the surface-fill issues. 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 __________________________ ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Plplot-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/plplot-devel
