setting X server DPI

[Patrick O'Callaghan]

On Tue, 2009-03-10 at 13:27 -0400, Tom Horsley wrote:
> Absolutely true, and absolutely the point. If you specify a 12 point
> font on a 46" 1920x1080 display, you will wind up drawing some
> random smudge of bits that is indeed able to fit on a line that
> is 12/72 of an inch high, but there aren't enough frigging pixels
> to render the font in any fashion that makes it remotely possible
> to discern what the character actually represents.

This true but it shouldn't be. It's true because the sizes of things in
X are defined in terms of pixels, and it's wrong because 12pt type is
12pt, no matter what medium it's on. It's an absolute size, not a given
number of pixels.

The fault is with how X works. Probably no-one remembers it now, but the
NeWS display server defined by Sun and based on Postscript did actually
manage real sizes, not pixel dimensions.

poc