Re: [Texmacs-dev] background patterns [was Re: Pdf marks and Re: adding pdf hyperlink support]

[Joris van der Hoeven]

On Wed, Sep 07, 2011 at 02:20:23PM +0100, Sam Liddicott wrote:
> > There is another issue concerning Postscript rendering which
> > has caused me headaches: how to use a picture as a background
> > pattern for a fill? I would like the picture to be an arbitrary
> > postscript file, if possible. For the moment, we print
> > the postscript file over and over again at different locations;
> > it would be better if we could define a macro for the file.
> 
> I have dug out my Adobe Postscript Reference Manual for you and see what I
> can come up with.

If there is no way to encapsulate an entire postscript file in a function,
then we would need explicit code for defining RGB images in postscript
from, say, a png file. I already did find out that such images can be
used as patters. However, this would require some additional coding and
maybe yet some more coding for reading png images.

On the other hand, if someone volunteers to write such code,
then this might actually be a good idea anyway. For one thing,
it might result in better image compression when exporting to Pdf.

Having native support for reading and writing, say, png images
would also be a good thing: we might then replace our icons by
png images with an alpha transparency. We might also generate
images for formulas in the Html export in a much more direct and
faster way. Notice that we still need things to work for both
the Qt and X11 version (so using the direct Qt support for
png images is not sufficient yet).

> (Sorry that it too so long to reply)

Don't mind for that; I am certainly in a wrong position to blame anybody...