Re: Re[2]: How to export text to EPS as text (no curves)?

[Lars Clausen <lrclause cs uiuc edu>]

On 7 Sep 2003, Alan G. Isaac wrote:
> On Sun, 07 Sep 2003 08:12:26 -0500 Lars Clausen <lrclause cs uiuc edu>
> wrote:
> > The problem is that we don't have a text export that preserves the size
> > of the strings, or we'd use that.  If we used regular (E)PS text,
> > strings would overflow their boxes or leave big gaps.
>
> I do not understand this claim.  PostScript text is entirely
> scalable.  If you can fit a box once, you can fit it at any
> scale.  Or are you saying you have no mechanism for
> computing the width or height of PostScript strings, so you
> cannot even fit a box once?  This is a very standard problem
> and there should be many applicable solutions on hand.
> (I realize I probably just do not understand the problem
> you intend to describe.)

The problem is that font scaling isn't linear, i.e. if you scale up a
string by *2, the width of the new string is not necessarily twice that of
the old one.  This is because fonts are rendered differently at different
resolutions to improve legibility, and especially for low resolutions like
screens there's also grid-fitting going on that distorts it even more.  See
<http://people.redhat.com/otaylor/grid-fitting/> to understand more of this
problem.  It's plagued Dia for a while now.

After that problem, there is the problem of how to embed the desired
fonts.  In many cases, we can make do with the standard PS fonts, but
anything beyond that, and we need to do a whole lot of stuff (including
possibly some copyright-problematic things) to get the right rendering.

> > There's work afoot to make a Pango renderer that does PDF
> > & PS, but there are some legal issues of the underlying
> > PDFlib to solve first.
>
> Can you point me to a discussion of these legal issues.
> (I am just curious.)

There's been very little real discussion, it seems, but what has been is
not good.  It's covered by the Aladdin license, which is 'free for
non-commercial use'.  See
http://pangopdf.sourceforge.net/phpwiki/index.php/QandA 

> In any case, give me the option of exporting the cleanest
> ordinary EPS files you can (with no embedded or simulated
> fonts), and I can always tinker with them ex post if need
> be.

We could do that (indeed, the Windows port, not having font-config, does
that).  Next problem: What does PS think of Unicode?  All text in Dia is in
Unicode, which isn't a problem for English writing, but for just about
anything else, it is.

-Lars

-- 
Lars Clausen (http://shasta.cs.uiuc.edu/~lrclause)| HÃrdgrim of Numenor
"I do not agree with a word that you say, but I   |----------------------------
will defend to the death your right to say it."   | Where are we going, and
    --Evelyn Beatrice Hall paraphrasing Voltaire  | what's with the handbasket?