Using Dia for book illustration

[Gerard Milmeister <gemi bluewin ch>]

Hi,

I am the coauthor of the book "Comprehensive Mathematics for
Computer Scientists" that will appear by the end April
at Springer Verlag.
We tried to use only open-source software to create the book,
i.e., LaTeX2e ... I created some 70+ illustration, and Dia
was the only open-source program adequate for this task.
First I am impressed by the quality and reliability of the
EPS output, an area where sodipodi is extremely weak. Also
by using Pango fonts in export I could use Unicode characters
which is very handy too.
Furthermore Sodipodi doesn't have much of support for technical
drawing like arrows. So Dia was the only option left. I would
have like something that had the features of both Sodipodi and Dia.
To make some of the more complex (3D) drawings I created the graphics
first in Mathematics then exported to PNG and imported it
as a picture in a separate layer in Dia, and then traced the lines
of the pixmap. This was a lot of work, but the quality it
generated justified it.
I know that Dia has been designed for diagramming, but up to now it
is the only program for Linux that is suitable for technical drawings at
all (there being no Illustratorm and Sketch for example
is awful at handling fonts). So I would like Dia to be extended
to a full-featured illustration program, I think the potential is
there. Here are some of my thoughts:
1. Rotation and Resizing of graphical objects.
2. Alpha blending would be useful.
3. More precise positioning including measuring. It is not easy
   to create two non-parallel lines of exactly the same length.
   Also there should be different ways to create
   circles and other objects, for example, by indicating the center.
   The grid is extremely useful, but snapping on the end of lines
   would be helpful too.
4. Font handling is good, but there should be minimal support
   for formulas, e.h., subscript and superscript, changing
   fonts within a text.
   I also noticed that font metrics on the screen don't
   quite match those in print, although this has been no
   real issue in practice.
5. I had some real fiddling to do because measurements (font sizes)
   are not absolute. There are three numbers I had adjusted:
   font size, scale in Dia, and scale factor in LaTeX's
   "\includegraphics"
6. The antialiased view is useful but slow (even on a 2400MHZ P4).
   Can this be improved?

Well, that's all I can think of now.
So, thanks for the great piece of software, and continue
with the development.

Regards,
-- 
Gérard Milmeister
Tannenrauchstrasse 35
8038 Zürich
gemi@bluewin.ch