Re: display-mm-width return value off on Windows

[Ralf Angeli]

* Eli Zaretskii (2006-07-06) writes:

>> From: Ralf Angeli <address@hidden>
>> 
>>                    display-mm-*   display-mm-*
>>         Real size  without patch  with patch
>> Width   330mm      320            305
>> Height  207mm      240            203
>
> That is still not a very good approximation, is it?

The values are more accurate than before.  With the change Jason
suggested they might improve even more.  If I find time I'll ask the
user who originally reported the problem to check a version of Emacs
with the change applied.

>> -  cap = GetDeviceCaps (hdc, VERTSIZE);
>> +  height = round (GetDeviceCaps (hdc, VERTRES)
>> +              / GetDeviceCaps (hdc, LOGPIXELSY) * 25.4);
>
> What is this magic constant 25.4?

As David wrote: millimeters per inch

-- 
Ralf