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

[David Kastrup]

Ralf Angeli <address@hidden> writes:

> * 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.

The reason this makes sense is that this is how the font size is
determined (the ratio between pixels and point size of a font), and if
one wants to match the dimensions of graphics to a font, one should
use the same algorithm.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum