Wayland surface units (Re: [PATCH 2/2] protocol: Support scaled outputs and surfaces)

[Pekka Paalanen]

On Wed, 22 May 2013 10:12:00 +0200
Alexander Larsson <alexl at redhat.com> wrote:

> On tis, 2013-05-21 at 20:57 +0300, Pekka Paalanen wrote:
> 
> > We use the units of "pixels" in the surface coordinate system, even
> > if they do not correspond exactly to any "real" pixels like
> > elements in a buffer or on screen.
> 
> Actually this is sort of a problem. Maybe the docs would be clearer if
> we just used a different name for these? "points"?

That is a good idea, but choosing a name is hard. I think points will
get too easily confused with font sizes or the 1/72 inches unit and all
that mess.

Follow Android with "dp"?
http://developer.android.com/guide/topics/resources/more-resources.html#Dimension

I'm not sure that is exactly the definition we want to use, with just
160 dpi changed to 96 dpi. I feel uneasy mentioning dpi at all. So
maybe not "dp", then.

We need a name for the surface length unit, since the surface local
coordinate system is such a central concept in Wayland.

I just can't seem to come up with anything serious.
- wayland units, wu
- wayland pixels, wp, wpx
- surface units, su
- surface unit pixels, sux
- surface pixels, sp, spx
- wayland surface units, wsu
- wayland atomic units, wau
- pips, pip
ehhh...


Cheers,
pq