Dear Alan and PLplot community, Please find attached an update for the Qt driver, allowing changes to the background colors (supporting transparency), based on svn revision 10819.
I should submit quite soon another patch for the driver, making the code a bit cleaner (not changing the general architecture of the driver though) and making the driver faster. Alban Alan W. Irwin wrote: > I have just (revision 10188) enabled alpha channel/transparency for our > background colour for the cairo and svg device drivers. These drivers thus > join the gd device driver in handling this correctly, and I hope later this > week, Alban will be able to enable the same functionality for the qt devices > (along with his planned changes to enable rgb background colour for the qt > devices.) > > For now you can see what semi-transparent backgrounds look like > by locally changing the second line of cmap0_black_on_white.pal from > > #ffffff 1.0 > > to, e.g., > > #ff0000 0.3 > > which gives a red mostly transparent background for the gd, cairo, and svg > devices (and an opaque red background for our devices which are not > transparency aware). > > I would also like to specify the transparency of the background conveniently > using the -bg command-line option. I was thinking along the lines of > > -bg ff0000_0.3 > > to specify the same semitransparent background that I gave as an example > above. The implementation would simply check the length of the option string > and if greater than 6, parse the first 6 as hex, check for the underscore, > and parse the remainder as a floating point value. Please comment _soon_ if > you forsee any trouble with that implementation idea. > > Of course, our current semitransparent background results look rather dull > because linux applications still are not as transparency aware as they > should be, and therefore, they currently tend to impose opaque backgrounds > of their own upon which the PLplot background is superimposed. To sort out > which background is which, you can sometimes specify a background colour for > the application. For example, the ImageMagick "display" application has the > -background option to specify an opaque colour for their background, and I > was able to use that "display" option to prove that _our_ background > transparency was working correctly for the gd, cairo, and svg devices. (Of > course, it would be nice if the "display" background could be > semi-transparent as well so I hope some ImageMagick developer is working on > that.) > > In the future, as Linux and other OS's become completely transparency aware, > I can forsee our semi-transparent background capability allowing for some > really cool effects such as superimposing our plots on top of other images > or just on top of the general desktop behind where one of our plots is > displayed. Anyhow, that was the motivation for the latest commit and will > also be the motivation for the planned change to the -bg command-line option. > > 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 > __________________________ > > ------------------------------------------------------------------------------ > Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day > trial. Simplify your report design, integration and deployment - and focus on > what you do best, core application coding. Discover what's new with > Crystal Reports now. http://p.sf.net/sfu/bobj-july > _______________________________________________ > Plplot-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/plplot-devel >
qt_patch.gz
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