Re: [ft-devel] gamma correction and stem darkening

[Werner LEMBERG]

>> For high-quality output with gamma correction, I think I need both:
>> (1) native hinting for TrueType fonts -- otherwise tricky CJK fonts
>>     fail
>> (2) stem darkening -- otherwise the text is too light after gamma
>>      correction

What you want doesn't exist yet, sorry, but I think this will
eventually come.

> 1) To get stem-darkening working with native TrueType hinting,
>    subpixel hinting/full ClearType handling is needed,

This is bad wording IMHO.  What Nikolaus wants to say is that we need
a special TrueType hinting mode that doesn't hint along the horizontal
axis while still interpreting the bytecode.  Horizontal hinting is to
be replaced with stem darkening.  To get good appearance it is
obviously necessary to have subpixel hinting/positioning, however, it
is *not* bound to ClearType (which I always mainly associate with
ClearType filtering).

> 2) So far, I failed miserably in understanding how this entire
>    TrueType hinting and ClearType stuff works so my attempts to do
>    something about it got nowhere.

I suggest that you install FontForge and use its bytecode debugger to
steop through some glyphs.  Note that FontForge doesn't support v38
hinting (there's no successor to George Williams, the retired author
of FontForge, who is going to add such code to FontForge,
unfortunately), but you should get an idea in general.

To have a v38 debugging session, you can use ftdebug, which has a very
simple TTY interface.


    Werner