[ft] 'unpatented' hinting and TrueType engine type

[Ineiev]

Hello,

Recently I noticed a change in default FreeType rendering
of one of the fonts I use; the change was not desirable
for this font, so I tried to reproduce the older behaviour.

I tested different configuration options from ftoption.h,
each time opening the font with FT_PARAM_TAG_UNPATENTED_HINTING,
as documented in ftoption.h, and without it.

I distiguish the interpreters by the form if the
outline: the 'unpatented' one produces a regular
rectangle (which is the desirable result),
the 'patented' one emits a trapezium.

The test program source and it's output is attached.
The command line was './dec lohit_hi.ttf 109', the font file being
http://savannah.nongnu.org/bugs/download.php?file_id=21450

It appears that:

When configured for FT_TRUETYPE_ENGINE_TYPE_NONE, it uses
the 'unpatented' bytecode interpreter in both cases;

When configured for FT_TRUETYPE_ENGINE_TYPE_UNPATENTED, it uses
the 'unpatented' bytecode interpreter when
ft2-truetype_tables.html#FT_PARAM_TAG_UNPATENTED_HINTING
documents the 'patented' one and vice versa;

When configured for FT_TRUETYPE_ENGINE_TYPE_PATENTED (current
default), it uses the 'patented' bytecode interpreter in both cases.

It means that either I do something wrong again (after all,
ftview shows rectangle in all configurations) or newer FreeType
versions in default configuration are uncapable to render
'certain Asian fonts' as they used to;
in the latter case, I'm really not sure what is intended,
but probably there should be more documentation details about it.

dec.c
Description: Text Data

dec.log
Description: Text Data