Re: [ft] Font rasterization

[Werner LEMBERG]

> Is hinting the default for FreeType?

Basically yes, but the default font flags is something to be selected
by the application.

> Does it need rewriting to use design metrics?

I think so.  At least for TrueType, you have to make a distinction
between rendering for screens and rendering on paper.  TrueType has
been designed so that up to a certain size and low DPI values, you
should use integer coordinates and hinted glyphs (which should be
optimized for a given ppem value), together with B/W rendering and
size-specific metrics which can differ enormously from the design
metrics.  Remember that the whole hinting issue has been invented
exactly for that.  It was revolutionary 20 years ago; today it's
rather a burden.

On the other hand, it is fully sufficient if you use integer
coordinates without hinting to get excellent results in case the DPI
value is sufficiently large.

Thus the Qt guy is right: For the UI, the `traditional' way is the
right one.

> From what I understand, the functionality's already in place, and
> it's just that Qt's not making use of it.  Could some of the
> developers of FreeType comment on the issue?

Microsoft's introduction of ClearType (which essentially provides
sub-pixel positioning for low DPI values) is a paradigm change, and it
took some years to make MS applications support that.  I don't know
whether Qt on Windows already uses ClearType features.  And yes, the
functionality is there, at least with the autohinter (and soon with
the TrueType engine too).


    Werner