font sizing question

[Ron Cococcia <ron cococcia request com>]

Hello,

I've bumped into a problem with an app I've been working on, and have 
been having some trouble determining the cause.  On one system (Intel 
i815-based) that I use, I run the app, and everything looks as it 
should.  If I move the drive (swappable drive) to another unit (Intel 
i830-based), the fonts are smaller.  It is running an XFree86 4.3.0.1, 
with gtk2.  It is running in 640x480 24bpp resolution.  The X driver 
(i810) is used for both sets of hardware.  As far as I can tell, the 
differences are basically in hardware only (with the proper modules for 
hardware support).

I am looking to figure out how the font sizes are determined.  Is there 
something that queries a driver (X, kernel, etc?) to figure out how to 
size a font?  Or maybe some hardware-specific routines in a library 
(gtk, pango, fontconfig, etc) that do this?

I'm not sure if this is the proper place to find this information.  If 
there's a better place to ask, please tell me :)  I'm kinda digging 
through message lists/google looking for any info, but any help or 
direction is welcome.

Thanks in advance,
Ron