Re: FT_Face scaling and pango

[Dov Grobgeld <dov grobgeld gmail com>]

I found it. PostScript is using a coordinate system of 72 points per
inch. Freetype2 is using fixed size integers of accuracy 1/64. Such
integers are returned as distances in the font decomposition of the
callbacks from FT_Outline_Decompose. 72/64 = 1.125 which was the error
I had in the scaling.

Regards,
Dov


---------- Forwarded message ----------
From: Dov Grobgeld <dov grobgeld gmail com>
Date: Nov 18, 2005 2:49 PM
Subject: FT_Face scaling and pango
To: gtk-i18n-list gnome org


Hello,

In the creation of paps (http://paps.sf.net) I have a problem scaling
from the coordinates given by the freetype call FT_Outline_Decompose
to postscript. Currently I had to manually scale the postcript
coordinates by a factor of 1.115 to get an approximately match between
the bitmap scaling created by pango and my postscript outlines. This
factor was found heuristically and I am trying to track down the
origin of it. Is there any explanation available describing the
various coordinate systems used within pango and freetype2, that may
help me?

Thanks,
Dov