On Mar 12, 2008, at 7:28 PM, Doug Hunt wrote: > Hi Hazen: > > The original 'mem' driver plotted into an unsigned char array with > size > 3 x height x width (thus no alpha channel). The cairo drivers plot > into > 32 bit RGB arrays (with an alpha channel). For the memcairo driver > (as a > first cut), I just copied in the 24 bits of RGB info into the 32 bit > RGB/alpha words, leaving the alpha channel 0. When cairo is done > with its > magic, the 32bit RGB/alpha words are copied back into a 24 bit RGB > array. > > I'd like to figure out how to get my graphics package to work with an > alpha channel and add an option to pass in 32 bit RGB/alpha words.
If I understand correctly, this alpha channel would be for the purposes of overlaying the memcairo array onto another array, possibly generated by some other rendering program? A reasonable alpha equivalent of plsmem() might be plsmema(), which would follow the convention that we used for the other alpha support channels. Then I guess it is just a matter of memcairo knowing whether it is dealing with a 24bit or a 32bit array. -Hazen ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Plplot-devel mailing list Plplot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-devel
