Re: [ft-devel] Issues due to commit "Fix metrics on size request for scalable fonts."

[Peter Hurley]

On Tue, 2012-04-03 at 09:53 -0400, Alexei Podtelezhnikov wrote:
> On Tue, Apr 3, 2012 at 9:05 AM, Peter Hurley <address@hidden> wrote:
> > Werner LEMBERG wrote:
> >> > We had report of regression in GTK markups rendering in Ubuntu
> >> > precise, (i.e <u>label</u> would render underlined), [...]
> >> >
> >>
> >> AFAIK, the problem is in gtk.  For years, FreeType had this metrics
> >> bug, and unfortunately the users got used to the appearance of far too
> >> widely spaced lines.  What FreeType now returns is what the font
> >> designer has had in mind while designing the font, and what can be
> >> found in the font.
> >>
> >> As has been stated in one of the Debian bug report comments, the
> >> amount of the vertical line spacing is something which *must* be
> >> configurable or explicitly set by the application.  >
> >
> > One outcome of integer scaling the metrics is that monospace fonts have
> > 'excessive' space between glyphs. Unlike vertical line spacing, there is
> > no way to directly control the max_advance metric value from the
> > application layer -- only the font stack has access to this value.
> 
> I'd like to see some images that show that. Please use ftstring. Also
> please remember that freetype renders glyphs and truthfully returns
> metrics. The text layout is not done in freetype.

Sorry, but to me it's pointless to use ftstring as the reference since
it doesn't use FT_Set_Char_Size or metrics.max_advance.

I get that text layout is not done by FreeType; I am saying that higher
layers in the font stack *do* use the metrics returned by FreeType and
now that the way those metrics have changed affects more than vertical
line spacing.

> > Integer scaling *may* have been the font designer's requirement.
> > However, it could be argued that if the font designer was using FreeType
> > to proof the work, that the 'intention' was for the font to look as it
> > did before this fix.
> 
> This is highly unlikely and hypothetical. Freetype is trying to
> improve the rendering all the time. Improving meens some changes in
> the way glyphs look.

I agree that my statement is hypothetical -- as was Werner's assertion
that "What FreeType now returns is what the font designer has had in
mind while designing the font".