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

[Ralf Angeli]

* Jason Rumney (2006-07-08) writes:

> But using LOGPIXELSX/LOGPIXELSY is not going to be any more accurate
> than what monitors report, or Windows makes up, since it is based on a
> dpi setting that is user configurable, defaulting to 96dpi,

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}'.

-- 
Ralf