Re: Pango crossplatform layout size query

[Richard Procter <richard n procter gmail com>]

On 30/04/2010, at 6:42 AM, Behdad Esfahbod wrote:

> On 04/12/2010 07:22 PM, Richard Procter wrote:
>
> > [re font metrics hinting] For me, the key to clarity is not  
> > quantisation
> > per se but whether or not the layout calculations try to minimise
> > inter-glyph spacing error arising from the limited precision of the
> > device, so as to buy better glyph spacing at the cost of a
> > device-dependent layout width. (Of course, I may be clearly having  
> > the
> > wrong idea :).
> >
> > I suspect that 'quantisation' carries those connotations for you and
> > so the ambiguity doesn't arise.
>
> We are basically talking about the same thing.

Good. My reason for going into this was to let you know why when
I read the documentation the significance of 'font metrics hinting'
flew right over my head. If I find time I will submit a doc patch.

> > > > Great. I take it that I am basically on the right track then and  
> > > > that
> > > > when you said cross-platform results without metrics hinting were
> > > > 'fairly robust' you were thinking of that single device pixel.
> > [...]
> By "more or less" I mean: it is supposed to work, but I'm fairly  
> confident
> that there are a few bugs...

Great - thanks for the reply.

Regards support of font metrics hinting on win32 - it just looks to have
been a typo, a comparision of CAIRO_HINT_METRICS_OFF against
options.hint_style rather than options.hint_metrics. Fix that, and the
win32 backend obeys the hint metrics setting. I will submit a patch
against cairo (and it's a good reminder for me that C enums are macros
in drag).

best,
Richard.