Resolution indpendence

Nicolas Mailhot nicolas.mailhot at
Fri Jun 27 09:06:57 PDT 2008

Le Ven 27 juin 2008 17:41, Soeren Sandmann a écrit :
> Behdad Esfahbod <behdad at> writes:
>> On Fri, 2008-06-27 at 16:49 +0200, Soeren Sandmann wrote:
>> > Behdad Esfahbod <behdad at> writes:
>> >
>> > > On Fri, 2008-06-27 at 10:59 +0200, Soeren Sandmann wrote:

>> > (2) The DPI is insufficient to compute any font size anyway
>> because
>> >     the right one also depends on the distance to the screen. You
>> >     really don't want 3 point fonts on a projector. You want
>> >     essentially the same size fonts as on your desktop.
>> Read my other mail.  Take dpi as dpi-at-arms-distance and everything
>> makes sense again.  For a projector, assume distance from screen is
>> the
>> same for the projector and the viewer and you have a fixed dpi
>> defined.
> You are assuming here people view different-sized screens at the same
> distance, but that is just wrong.

It's not. Office and home furniture does impose distance limitations
you know (ignoreing laptops, where the limitations are even more

> Consider a 60" TV with a resolution of 1920x1080. This device has a
> dpi of 30, but if you use that value, you get really tiny fonts and
> you don't want that because you are looking at it from your couch, not
> at "arms length".

TVs are TVs and not computer screens. They can not be treated the same
way because simply the hardware compromises, expected use, and
limitations are different.

> Your algorithm above would consider it a "junk" value, but there is
> nothing junk about it. The TV is reporting it's size and resolution
> correctly.
> What *is* junk is attempting to compute stuff that cannot be
> computed.

What is junk is declaring something is hard and then dumping the task
on the uninformed user to do manually.

>> > (4) You can override it in the control center anyway.
>> That's no reason.  It should Just Work.  And in this case, it has
>> been
>> Just Working so far.  Just don't break it please.
> The "Just Work" solution is to pick 96 dpi because it works in 99.999%
> of cases.

It does not

> Users can select bigger or smaller fonts if they want to, or
> they can override the dpi setting.

They do not. Users do not know what dpi is and mishandle it in
spectacular ways when they're pointed to dpi settings.

> Believing the X dpi is apparently new in 2.22, so it hasn't been
> "working" so far.

It's been working for years. KDE used and uses it today without problems
What's not been working is the way some people handwaved that trying
to use it was hard, FUDed on angles of view, and kludged a gconf key
to force 96dpi everywhere (encouraging people to write broken apps)

Nicolas Mailhot

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