Re: Font Metrics concerns

With the current spec, what happens to drop caps when the first line
contains a synthetic superscript?



On Tue, Feb 10, 2015 at 2:26 PM, Alan Stearns <stearns@adobe.com> wrote:

> On 2/10/15, 1:05 PM, "John Daggett" <jdaggett@mozilla.com> wrote:
>
> >> > I don't think defining an API for font metrics is the right place to
> >> > start. First off, you're really probably talking about some form of
> >> > *line* metrics rather than actual font metrics.
> >>
> >> The desirability of an API for linebox metrics (which is not under
> >> dispute, and was also agreed to at the Houdini meeting) does not in
> >> itself argue for the undesirability of a Font metrics API in addition.
> >
> >The argument has been made that providing font metrics is a good
> >starting point and I don't think it is. If an author is trying to get
> >line metrics, then *those* are the metrics for which there should be an
> >API. The two should not be conflated, since there are many scenarios
> >where knowing the metrics for fonts used along a line will *not* tell
> >you the line metrics.
>
> There are some cases where line metrics are needed, such as trying to
> position a drop cap’s baseline with the appropriate baseline in the main
> text. There are other cases where just the font metrics are required, such
> as trying to size a drop cap based on cap height.
>
> Both line metrics and font metrics will be useful. I don’t have a firm
> opinion on which is the better ‘starting point’. But I do think that
> progress can be made on both in parallel (line metrics should be part of
> the fragment tree spec).
>
> Thanks,
>
> Alan
>
>