On 2010-09-22 15:32-0700 Alan W. Irwin wrote: > Back in the mists of time, I figured out a way (I think with display > options) to show a semi-transparent background for real, i.e., without > the checkboard and with the desktop (whatever it is) showing through > the plotted image. That was a really cool effect, but I cannot > remember what I did exactly. Has anybody figured out how to do that?
Never mind. Google to the rescue. Use the -immutable option for display. However, that doesn't work quite correctly on my current KDE4.4 desktop. The experimental result is complete transparency if the alpha channel is 127 or less and complete opaqeness if the alpha channel is in the range from 128 to 255! I have read elsewhere there are a lot of compositing fixes in KDE4.5 so transparency effects may work better once I upgrade to that. If you have good transparency handling with your desktop you may find the current test_memcairo.py example (with alpha = 200, dark gray background), gives an interesting effect with "display -immutable". But in all cases just middle click with the mouse on some part of the image to find the exact colour and alpha that is meant to be displayed for that part of the image. 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 __________________________ ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing. http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
