Resolution indpendence

Glynn Clements glynn at
Fri Jun 27 12:43:21 PDT 2008

Nicolas Mailhot wrote:

> > There are two points of physical information:
> > 
> >   A) Dots per inch on the display surface (LCD panel, TV screen,
> > projector screen, The Wall, ...)
> > 
> >   B) Viewing distance
> > 
> > Those two are very real and can be measured.  If we have both, we can
> > compute a third value:
> > 
> >   C) Normalized dpi / angular resolution / whatever you call it.
> > Physical dpi times viewing distance does the job.
> > 
> > 
> > At the end, C is all the application developers care about.  That's why
> > I suggest we redefine application DPIs to be that.
> Actually they also need to care about
> D. Preferred user font size in pt (which is then converted in pixels
> using C)
> Without D people fake C to change what D should be like

And also:

E. Preferred user font size in pixels.

Without E, people fake A so that they don't have to reconfigure
everything which insists on using point sizes.

And note that the issue isn't just fonts. If you have a bunch of 16x16
icons, you had better not be rescaling them by a non-integer multiple
unless it's a relatively large multiple. 2x is likely to be more
legible than 2.5x.

Glynn Clements <glynn at>

More information about the xorg mailing list