* Eli Zaretskii (2006-07-09) writes:

>> From: Ralf Angeli <angeli@caeruleus.net>
>> 
>> If `GetDeviceCaps (hdc, HORSIZE)' always assumes a fixed DPI value
>> that would explain why the values are so inaccurate especially on
>> displays with a high DPI value.  In that case I think it makes sense
>> to use the DPI value when calculating the size (as my patch does) and
>> assume that the user set it to a value matching her monitor.
>> 
>> As a last resort we could provide user options (in Emacs) for setting
>> the correct size of the screen which will be used as return values for
>> `display-mm-{width,height}'.
>
> Sounds like a good plan to me.

Here are change log entries and patches to achieve that:

2006-07-11  Ralf Angeli  <angeli@caeruleus.net>

	* frame.el (display-mm-height): New variable.
	(display-mm-height): Use it.
	(display-mm-width): New variable.
	(display-mm-width): Use it.