Resolution indpendence

[Steven J Newbury]

On Mon, 2008-06-30 at 15:35 +0100, Barry Scott wrote:
> Nicolas Mailhot wrote:
> > Le vendredi 27 juin 2008 à 13:32 -0400, Behdad Esfahbod a écrit :
> >   
> >> On Fri, 2008-06-27 at 18:06 +0100, Steven J Newbury wrote:
> >>     
> >>>> HAL sees that it's a TV, assumes a viewing distance of 4m, computes a
> >>>> dpi-at-arms-distance value of 30 * 4/.7 = 171dpi.  Very decent.
> >>>>         
> >>> This may well be sufficient, but it is a hack.  Ideally it would be better
> >>> to have a specific "typical viewing distance" value for the hardware device
> >>> that the toolkits/font renderer/compositor could pick up and utilize in
> >>> relevant contexts.  It's probably too late for the first two however.
> >>>       
> >> 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
> >
> >   
> E. Screen magnification factor.
> 
> I would like to be able to just add a magnification to make everything on
> the screen either bigger or smaller. Images need to scale with text etc.
> This is independent of D.
I hinted at this elsewhere in the thread, a tunable knob for desktop
scaling factor, and could easily be tied to hotkeys.  This would
probably keep most happy.