[Freetype-wiki-commit] [A freetype Wiki] Update of "AsianCharacters"

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The following page has been changed by AaronBrady:
http://freetype.freedesktop.org/wiki/AsianCharacters

New page:
= Asian Character Rendering Problem =

Due to the PatentsLimits of freetype, if you want to redistribute an application using freetype, you may have problems rendering some of the characters with some asian (and maybe other) fonts.

(if image upload is enabled, I have screenshot of the problem. Also, I have a quick opengl app that will display the rendered character if passed a font on the command line at different sizes, also could be uploaded (if moin moin supports this))

Here is an example character:
亜

I Experienced this with 'gulim' font, but msgothic. Here is a transcript from JanSlupski:
{{{
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.
}}}

The problem didn't pop up with some fonts, like msgothic (as far as I could tell). So you may or may not experience this.

Freetype didn't experience this problem with the bytecode interpreter enabled.