Re: Metapost bug with font size... (Was: PyDia and Metapost)

[Hans Breuer <hans breuer org>]

On 16.02.2006 21:42, Rob McDonald wrote:
> > I think I've found the problem.  The text size appears to be keyed into
> the
> > zoom level selected on screen.  Zoom to 100%, the exported text looks
> right.
> > Zoom to 200%, the font gets bigger.  Zoom to 400%, everything gets bigger
> > yet.
> >
> > Previously, when I deleted 14 of the objects, I must've selected some
> > intermediate zoom level.
> >
> > Hope this helps, this one ought to be pretty easy to fix.
>
> If someone wants an easy way to re-create this bug, the following procedure
> does it for me...
>
> 1) Start Dia.
> 2) Insert a text label "foo".
> 3) Set the zoom to 100%.
> 4) Export a MetaPost file foo1.mp
> 5) Set the zoom to 200% (or anything else)
> 6) Export a MetaPost file foo2.mp
> 7) Compare the two files.  diff foo1.mp foo2.mp
>
> The font scaling parameter will be different, while it shouldn't be.  The
> exported output should in no way be tied to the current on-screen view
> (scroll bar position, zoom, grid on/off, etc.)
>
> I would appreciate if someone else would confirm this problem, but I'm
> pretty sure I've seen it in 0.95-pre1 Windows and 0.94 Linux.
>
> I tried following through the code where the MetaPost export does a lookup
> for the font size.  It makes a call to pango and that's where I decided to
> defer to the experts.
Just looked into it and it appears to be a really simple solution.
Currently set_font() is ignoring the passed in parameter 'height'
which has the size independent of the scale.
Instead their is a call to dia_font_height() which apparently returns
a scaled font size. The latter may be a bug in itself but the whole
font handling is a little messy at the moment;)

Anyway, as noted before, I'd like to be able to reproduce the complete
issue, so could you please file a bug in http://bugzilla.gnome.org
and attach the information requested?

Also note: the size currently used at zoom 100% is different from the
size passed in (0.56 vs 0.80). Would that scale explain the size
mismatch you have mentioned earlier?

Thanks,
        Hans

-------- Hans "at" Breuer "dot" Org -----------
Tell me what you need, and I'll tell you how to
get along without it.                -- Dilbert