code coverage problem when using fontconfig/freetype

[Bin Chen]

Hi,

I am curious about a problem of code coverage and font using
fontconfig. I know in fontconfig you can specify many font file of one
'family', take a example of Chinese, I see many internet articles to
tell people to configure their fonts using two or more fonts for a
family, usually the first one is only cover the English characters,
and the second can cover both English and Chinese characters.

It seems that program(not sure the fontconfig or the user application)
can use the English font first if it only display English, but will
change to Chinese font once the English font can't have enough
coverage...

Can anyone tell me how to do this? Personally I wrote a program but
can't do this, I don't know whats the problem.

Thanks.
Bin