[ltp] 15" DisplaySize (DPI value)

[Anders Hermansen]

Peter Frühberger wrote:
> noc ops schrieb:
>> Based on the below formula my DPI value doesn't appear to be making
>> sense. Not sure I'm missing something.
>>
>> I would appreciate if someone could validate this value.
>>
>>
>> I have a laptop (15") w/ 1024x768 (max) resolution. My xdpyinfo output
>> displays 85x85 dpi?
>>
>> formula:
>> diagonal mm = diagonal inches * 25.4
>> horizontal mm = 4* diagonal mm / 5
>> vertical mm = 3 * diagonal mm /5
>>
>> 381mm = 15 * 25.4
>> 305mm = 4* 381mm /5
>> 229mm = 3* 381mm /5
>>
>> DisplaySize = 305  229
>>
>>
>> Any insight will be appreciated.
>>
> 
> seems to be correct, I use the same values!
> fritsch@todesstern:~$ less /var/log/Xorg.0.log |grep DPI
> (**) RADEON(0): DPI set to (85, 85)
> 
> fritsch@todesstern:~$ cat /etc/X11/xorg.conf  |grep DisplaySize
>         DisplaySize     305 229

I reinstalled Debian on my t40p the other day. And I had some problems
with the DPI setting even after setting correct DisplaySize.

The problem had several parts.

1) gdm had a dpi override. See:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=339707
I had to remove -dpi 96 from gdm.conf

After that change "xdpyinfo | grep resolution" gave the correct output
of 125x125. I think xdypinfo on a running X is the best way to check
that the "system" dpi setting is correct.

2) Gnome seems to have it's own dpi value. I had to run the gnome font
settings program and set the DPI there manually, I could not set it to
use the "system setting". I think the default was 96dpi, but I'm not
sure. There is a gnome bug about it here:
http://bugzilla.gnome.org/show_bug.cgi?id=104341

3) Firefox didn't show fonts as desired. I found a dpi setting in the
preferences. I don't remember the original value, but I set it to
"System setting" and that made it better. There is a bug about it here:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=270818


Anders