Gdk Postscript backend

[Paolo Molaro <lupus lettere unipd it>]

Hi folks.
I just commited my first try at a postscript backend for Gdk.
I added support for custom drawing operations on
GDK_WINDOW_DRAWABLE drawables through the use of drawing engines
(see the GdkDrawableClass structure).
The postscript engine is almost complete (needs pixmap and tile support
and configurable font handling): this is a port of the X print server.
I need to read a book about DSC to let the engine output
comments correctly.
A metafile backend is in the works.

A few changes were required to GdkFont and GdkGC to make this stuff work
well: GdkFont stores the font name now and GdkGCPrivate keeps track
of the clipping region, the dashes and the complete imformation about
background and foreground colors (this is was not provided by 
GdkGCValues).
Now the Region code is in gdk, so we can keep track of the clip
rectangles: it needs a routine to convert clip masks to a list
of rectangles.

You'll find a test program in gtk/testps.c.
The code is in the ps-mf branch so you can comment on the
interface and on the implementation.

Comments, bugfixes and improvements are welcome.

lupus

-- 
"The number of UNIX installations has grown to 10, with more expected."
    - _The UNIX Programmer's Manual_, Second Edition, June, 1972.