Re: [ft-devel] State of TrueType interpreter v38 and up?

[Werner LEMBERG]

>> There is a misunderstanding, see above.  `Native' ClearType doesn't do
>> y-only hinting!  It's simply that advance width modifications are
>> ignored in Windows at a later stage, namely in the rasterizer.
> 
> I'm confused. Is this "native ClearType" actually called "Natural
> ClearType" or "natural advance widths"?

MS created too many buzzwords :-(

  `Native ClearType ' means `no ClearType backwards-compatibility
  mode'

  `natural ClearType mode' is DWrite talk for subpixel positioning

  `natural ClearType widths' is GDI talk for integer pixel positioning
  with subpixel rendering.

> What I meant to say is I want the part of ClearType that does Y-only
> hinting.

MS Windows doesn't support that, and FreeType doesn't support it
either.

> Does GETINFO == 39 (v2.0) and 40 (v2.1) bring anything to the table
> that would be relevant to FT?

Versions 39 and 40 essentially add different rendering modes only,
which isn't directly relevant to FreeType.

>> The second one consists how the hinted outlines are converted to
>> raster images.  There are big differences between the MS engine and
>> FreeType, which can't be `fixed' without completely redesigning
>> FreeType.
> 
> Could you provide some specifics?  Do you mean how the rasterizer
> handles anti-aliasing and subpixel-rendering?

The latter: MS uses super-sampling, which *virtually* increases the
device resolution by a factor of 10 or so, while FreeType does
*really* increase the resolution.


    Werner