Emacs, colors and gdk-pixbuf.

[Jan D.]

Hello.

Some time ago there was some discussion about improving image and
color handling in Emacs.  One suggestion as to use gdk-pixbuf to
handle images.  I have made some tests, the actual code to get
gdk-pixbuf in is not that big.  I haven't actually checked if this
does make color handling better.  But there are some issues I'd like
some comments on.

First, gdk-pixbuf is inherently single displayed.  This means that
Emacs would be limited to one display.  Since GTK also is 
single-displayed
(perhaps not 2.2, there has been talk about some changes, I haven't 
checked
this yet), we could make gdk-pixbuf the default for GTK.

The part of gdk-pixbuf is the part that renders into X11.  Emacs could
use its own version of this code, suitable modified.  Is that something
people think is OK (using private versions of other libraries)?  Must
license issues be investigated or is it OK to modify stuff from GTK?

Another thing is that gdk-pixbuf may have been compiled with image
support that is different from the one Emacs has today (i.e. gdk-pixbuf 
may not have, for example, TIFF support compiled in).  Should we
try to make a configure test to see what image types gdk-pixbuf 
supports,
and then fall back to "native" support for the others?  Or just fail
at runtime if an image type is used that gdk-pixbuf supports?

Comments welcome,

        Jan D.