Re: [ft] Patent issues

[Werner LEMBERG]

> The autohinter has been previously rejected because it produces
> distractingly inconsistent character heights below 18px tall (but only
> with even pixel heights?).

Hmm.  This is a bug then.  Can you prepare something and put it into
the bug tracker?

> I've tried Arial from my Vista machine and from an XP machine, as
> well as a dozen other fonts, scaled them up and down, and they all
> look great with the native hinter.. just as Windows rasterizes them.

Good :-)

>   So why does the unpatented native hinter look so much better for
> me than the web site says it should?  Are there specific situations
> I'm missing that reproduce the rendering artifacts?

There is just a very small set of instructions related to diagonal
lines which are affected by the Apple patent.

>   Just to confirm, using the binaries from sourceforge,

We do provide binaries?  You probably mean archives, do you?

> it is impossible to activate the patented hinter at runtime, right?

Yes.

> I'd have to alter ftoption.h and recompile in order to violate the
> patents.

Yes, but please read the comment for
TT_CONFIG_OPTION_UNPATENTED_HINTING how to actually activate the
native bytecode interpreter for fonts which are not in our compiled-in
`whitelist' of CJK fonts which need this option unconditionally.

It's probably easiest to compare the different hinting modes with
either ftdiff or ftview.  Additionally, you might compare a normal
FreeType build (make; make) with a developer's build (make devel;
make) -- the latter activates the patented bytecode interpreter
automatically.


    Werner