> Not unless you're planning on using the BMP format (which means
> eliminating g.pnmcomp); it doesn't work with other formats.
OK. I missed the BMP part.
> [Essentially, the image format needs store the actual image data as
> raw 32-bit pixels, which rules out both PNG and PPM/PGM. 32-bpp BMP is
> just that: a 54-byte header followed by raw 32-bit pixels. TGA and PAM
> might also be viable.]
> On that subject, you really should look into eliminating g.pnmcomp.
> AFAICT, wxWidgets doesn't feature blending (although it should be able
> to do compositing with binary mask), but you may be able to use e.g.
> PIL for that. Performing compositing internally would save on I/O when
> enabling, disabling and re-ordering existing layers.
We're already doing internal compositing with the barscale/legend overlays,
using PseudoDC's. And I think that it is pretty easy to draw with a
transparent background with other DC's. I also see several ways to get
translucency in the demo. would mean reworking the rendering engine, but
probably worth it in the end.
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University