On 2008-07-03 02:44-0700 Jerry wrote: > The alpha channel example, Example 30 e.g. x30c, generates Postscript > files that do not display the transparency effect on my OS X machine. > The first page has the colored boxes but without transparency; also, > there is no black border. > > The second page shows only a single large red box with no alpha and > with a black border only at the top and right. Also, there is a black > hairline near the bottom of the red square which, when dissected with > a graphics program, reveals that the big red box actually is two red > boxes and the black hairline is a small gap between them. (Small gaps > between abutting graphics shows up in other places such as in surface > plots, so this might not be unique to this example.) The black > hairline notwithstanding, dissection in a graphics program shows that > the smaller colored boxes are in fact present but completely obscured > due to lack of transparency in the red box which lies in front of them. > > The two pages of this example display the same on either Adobe Reader > 8.1.2 or PDF viewers based on Apple's PDFkit such as Preview and > Skim. However, I notice that Adobe Reader will not read Postscript > files (has that always been the case?) and I converted the Postscript > files to PDF using Preview, Apple's reader app; there could be a > problem with the conversion that caused the Adobe Reader results to > be the same. > > Safari 3.1.1 and Firefox 3.0 display the SVG files also without alpha > and with a different set of other artifacts. > > The PNG file displays with no alpha and pastel (that is, faded, or > reduced saturation) box colors from page 1. (Page 2 is not generated > or does not display when I open the file.) The amount and nature > (brightness) of the fading depends on what program I use to view the > file. > > The JPEG file displays proper colors and borders for page 1 but no > alpha. > > GIF looks same as JPEG. > > Short version: no alpha to be seen anywhere on my machine.
Are you running the gd-related driver (png, jpeg, gif) properly to get the second page? You need the "familying" option -fam. For background on this see the section entitled Family File Output in http://plplot.sourceforge.net/docbook-manual/plplot-html-5.9.0/output-devices.html Another comment is that relatively few drivers support alpha transparency at this stage. To see comments about the status of such support for various drivers, use the svn log --verbose command in the drivers directory and look for "alpha". It appears from that log that _if you have the correct version of libgd installed_ you should be getting alpha results for example 30. Those results should look similar to those obtainable at http://plplot.sourceforge.net/examples/demo30.php (which are the results of pngcairo, IIRC). 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 __________________________ ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Plplot-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/plplot-devel
