Resolution indpendence

Glynn Clements glynn at
Fri Jun 27 12:29:06 PDT 2008

Steven J Newbury wrote:

> > > > (whereas using the physical resolution certainly has caused problems).
> > > 
> > > Only because there are bugs, in particular deep GNOME bugs, that were
> > > hidden (and festered) by forcing 96 dpi some years ago (because if
> > > windows is doing it, it can't be wrong - oh, wait vista is not doing
> > > it anymore, so it was a stupid hack after all?)
> > 
> > No, even if everything worked as it should, it would still be
> > problematic. The problems will only go away once 200+ DPI monitors are
> > the norm. Until then, the pixel grid will continue to matter.
> > 
> > If I run my 22" monitor at 1280x1024, I expect to see a physically
> > enlarged version of the image which I get on a 17" monitor at
> > 1280x1024, not an illegible approximation to what I would see on the
> > 22" at 1920x1440.
> You are using a strawman argument here.

Really? Because I'm sure I saw people suggesting that the UI should be
layed out in physical units, meaning that for a given screen size, the
amount of space allocated to various UI components would be entirely
independent of the resolution.

> > > > Moreover, ...
> > > >
> > > > Ultimately, ...
> > > 
> > > That's all excuses to let the problems fester and hope they'll blow up
> > > on someone else's watch.
> > 
> > WHAT problems? The only problems I have had have been by developers
> > who are absolutely insistent that physical dimensions absolutely MUST
> > matter to me, in spite of the fact that they don't.
> The problems that arise by developers using pixel units where they
> should be using pt sizes, proportional or physical units.

Using physical units (which includes point sizes) implies that a
monitor of a given size will display the same amount of content
regardless of the resolution.

I'm not sure what you mean by "proportional" units. If you're
referring to a percentage of the screen dimensions, exactly the same
problem occurs there.

> > Even 300dpi laser printers use hinting to align glyph boundaries to
> > the pixel grid. That may be for quality rather than legibility per se,
> > but it's still noticable at that resolution, let alone on a 100dpi
> > monitor.
> That's correct they use hinting, in exactly the same way as modern
> graphics renderers do for computer displays.  Have a look at what
> freetype/Xft does.  Nobody is suggesting ignoring the pixel grid, it is
> necessary to be aware of it at the rasterisation level to achieve a high
> quality output, but this doesn't mean application programmers (or
> users!) should need be aware of it!

It's necessary to be aware of it at the level at which the UI is laid
out. Any UI component which conveys information (text, image) has to
span enough pixels that the rasterised image is legible. Unless you
have a particularly high resolution (or poor eyesight), it doesn't
need any more than that.

Glynn Clements <glynn at>

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