Re: extending pstricks terminal driver

[Petr M. <mi...@ph...>]

> > >>     plot '<convert table.png avs:-' binary filetype=avs with rgbimage
> > >>
> > >> Nowadays gnuplot is typically compiled with the gd library. Therefore it
> > >> should be pretty easy to use the gd-library to load png/gif/jpg images
> > >> directly. I think it may not be too much code in breaders.c. Could somebody
> > >> contribute this feature?
> > >
> > > I honestly don't see quite how that would work.
> > > Using libgd, or libpng for that matter, will result in an in-memory copy
> > > of the bitmap image.  But that's not exactly what the binary file input code
> > > wants; it expects to read a stream of binary data on the input fd, so that it
> > > can filter, re-map, combine fields, etc.  It seems to me that one would
> > > have to write a new input layer that dummies up access to an in-memory
> > > bitmap as successive reads to a fake pipe.

The abstraction layer ... cannot be this done in some easy way? Currently 
there are fread(f, ..., bytes) ... so instead of fread() there would be 
memcpy().


> > > What would we gain by adding all this extra code? Isn't it much better to let
> > > an external utility do this for us, as in the example you quote?
> > 
> > One would gain readability. I would never have come to idea to use so
> > complicated code to be able to read PNG images.

The gain would be portability and speed. We could put lena.png and lena.jpg 
into demos/ and be sure that these demos can be run by Windows executables 
as well.

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PM