Physical ouptut sizes

[Matthias Hopf]

On Oct 07, 06 12:46:10 +0200, Nicolas Mailhot wrote:
> > But that is actually a deficiency in the font scaling system, which
> > tries to get the same font size in meter (well, mm in fact), independent
> > of the screen resolution.
> 
> Actually the problem is it *doesn't* try to get the same font size in
> meter (well, mm in fact), independent of the screen resolution, so
> people got used to lying about the screen resolution instead of changing
> the font size.

Well, I think this is just another way of putting it, I guess we
basically mean the same.

> > The IMHO cleaner solution would be to either
> > have a desired standard font size, or some sort of a general font
> > scaling factor.
> 
> People faking the absolute DPI used by the font system at the user level
> breaks badly for systems where the user is roaming from one hardware

I never meant user level. I thought about system dependent values. Maybe
an additionaly user scaling factor to reflect personal favorites.

The main problem is what to reflect with the system dependent
configuration. Specifying font size in mm is apparently wrong (remember
projectors), font size in pixels is wrong as well (remember 300dpi
monitors). Frankly said, the best I can come up with is something like
for an individual system tuned size in pixels of a well readable font.
Very fuzzy indeed. And difficult to tell what this is in a typical
projector environment, where you have people sitting 2m and 20m from the
image.

> People setting their preferred font ratio by setting a font size in pt
> does not work either - you will receive documents in sizes other people
> specified, so even if you choose 24pt as preferred size you'll have to
> handle 12pt documents (the w3c tried very hard to avoid this problem by
> inciting site authors not to specify an absolute font size, but we all
> know it mostly failed. and this would have only worked for web pages
> anyway)

User settings are another wormhole :-(

> 1. the X server reporting the exact hardware DPI (in the case of
> projectors: perceived DPI) to provide an hardware-independant and
> user-independant baseline.

I don't like this 'perceived DPI' als the only way of telling this -
there are times where you want to make a line *exactly* 10cm long, no
matter in which environment - e.g. in CAD.

That's why I mean the currently available metric values are not
sufficient. You could add a 'perceived DPI' value, but I do not consider
this the natural specification.

> 3. each user selecting *once* the zoom factor to apply over the raw
> X-server provided DPI so the default font size in pt looks good. This
> would be the only user-level tuneable

Agreed. Well, maybe two values, one overall, and one font only scaling
value (you might stick with 1:1 ratio for images, but on 300dpi monitors
that might end up too small).

Matthias

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