Re: puzzled by metrics

[Matthias Clasen <maclas gmx de>]

Am Fr, den 23.01.2004 schrieb Owen Taylor um 16:16:
> On Fri, 2004-01-23 at 04:42, Luca Padovani wrote:
> > Hello,
> > 
> > I don't understand what is wrong with the following experiment. I ask
> > Pango to layout three chars (x, +, 1) and I get the following metrics:
> > 
> > Pango font, pango_layout_get_extents:
> > 
> > x Ascent= -12288 Descent= 30720 y=  12288 height= 18432
> > + Ascent=  -9216 Descent= 30720 y=   9216 height= 21504
> > 1 Ascent=  -7168 Descent= 30720 y=   7168 height= 23552
> 
> You are getting the "Ascent" value from PANGO_ASCENT(rect)? That's
> only meaningful for a rectangle that expresses positions from 
> the baseline, like the extents of a PangoLayoutLine or glyph
> extents.
> 
> Look at the macro definition, draw some diagrams, and I think
> you'll see how it all works :-)

Ideally draw the diagrams in a form suitable for inclusion in the API
docs...

Matthias