fonts for vertical bopomofo stacks

Does anyone know of any fonts that will automatically compose plaintext
bopomofo strings such as "???" into vertical stacks with proper
placement of the tone mark (as shown here
<http://rishida.net/blog/?p=494>)? To clarify, I would like to produce
sequences of bopomofo stacks without adjacent characters: that is, the
precomposed character-bopomofo glyphs, such as what the
"HanWang[...]ChuIn" fonts here
<http://www.wazu.jp/gallery/Fonts_ChineseTraditional.html> provide, are
not what I'm looking for.

(I prefer vertical layout of bopomofo even in horizontal text, because
that will let me use spaces for word segmentation; otherwise I will need
to use spaces to distinguish "??" (za-) from "? ?" (zi- a-).)

Stephan
Received on Fri Sep 16 2011 - 21:44:29 CDT