[Gnome-print] Font metrics & resolutions

[Lauris Kaplinski <lauris kaplinski com>]

Hello!

While working on gnome-font library, I generated some demo pictures,
illustrating actual font metric dependance of final output resolution.

The can be found at:

http://www.kaplinski.com/lauris/fonts/

The idea is following:
12pt TrueType font is scaled/hinted to given printer resolution. Text is
laid out, using those metrics, and saved into semi- resolution-
independent glyph lists (keeping inter-glyph distances optimized, but
using original layout for word placement). Those glyph-lists are rendered
onto canvas with zoom factor 3:1

On red/gray picture red text is laid out for 72dpi printer, gray for
150dpi one. On blue/gray picture blue is for 600, gray for 1200 dpi
printer.
I was surprised, how big are actual differences even in the case of 600 /
1200 dpi! There is possibility that FreeType1 does not compute metrics the
correct way, but I think that is highly unprobable.
I consider that data as a justification for keeping separate, 'master'
output device adjusted font class in gnome font, in addition to unscaled
and final ones.

Lauris