A question about fonts

[Marty Jack]

On 03/09/2011 08:55 AM, Andersen, Jan wrote:
> Sorry for posting this here, where it is almost certainly not appropriate, but I don't quite know where to ask, and I suspect some of you guys probably do. So, this is my question:
> 
> I work a lot with Chinese, and need to be able to display the full range of CJK characters in Unicode; unfortunately that exceeds the capacity of all current font specifications (that I know), and I would like to see if I can do something about it. After all, when you display a character, what you need is to take your character representation (eg UTF-8) and look up a glyph - if things are reasonably sensible, it ought to be fairly doable to replace that part from somewhere and replace it with, say, a database interface. But where do I even begin to understand font-handling in X?
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I don't think things are quite as dire as you suggest.  It should be possible to put together on one system a set of fonts that cover all the Unicode points you need.

Here is one start to finding those fonts:

http://en.wikipedia.org/wiki/Unicode_typefaces

The major parts are:

Fontconfig.  Given something to display, find a font that contains a way to display it.

Freetype.  Do the mechanics of looking in font files to map Unicode to the glyph definition, which in the case of a scalable font is expressed as lines and splines.

Pango, Harfbuzz (part of Pango), Qt.  Do the mechanics of laying out glyphs along a particular path, taking into consideration writing direction, kerning.