Re: [ft] east asian characters rendering incorrectly

[Jan Slupski]

On Tue, 7 Jun 2005, Aaron Brady wrote:

> Hello,
>
> I'm having a problem with some freetype east Asian characters rendering
> incorrectly. What happens is that as I scale the characters they look
> okay sometimes, and at other times pieces seem to fall out of them.
>
> I can provide more information, and I'm looking into it further, but I
> wanted to see if anybody had seen this problem.

Hi,

I would guess that this can be caused by the fact that you are not
using bytecode interpreter (that is disabled by default because it is patented).
Some Asian fonts relays strongly on bytecode interpreter and cannot be 
rendered well without it.

If this is an issue, you may be getting right characters on certain
font sizes - there where the font provides embed outlines.
But whenever font engine has to create outline itself (normally only a
few font sizes are embed) it fails because of lack of bytecode interpreter.

You can test if this is the problem by turning on the bytecode
interpreter (compile time option - TT_CONFIG_OPTION_BYTECODE_INTERPRETER
in include/freetype/config/ftoption.h), and later use 
TT_CONFIG_OPTION_UNPATENTED_HINTING (same file - below) workaround.

Unfortunately unpatented hinting often fails rendering latin alphabet
(eg. Arial font), that normally works well without bytecode interpreter
at all.

Regards,
Jan

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