This document defines procedures to display Hershey fonts using the
BGI1 interface.
A replacement for |(out-text ...)| is provided. The format
is intended to be an imitation of Donald Knuth's TEX typesetting system:
- New fonts are selected with |||〈name〉 or
|||〈name〉
@
〈scale〉.
Remember to type double backslashes in a Scheme string!
- || selects a font 2 levels smaller.
- || selects a font 2 levels larger.
- || and |&vert#vert;| set the text direction.
- || delimit a group. The previous orientation, size, and font
are restored after the closing acculade.
- |^| and |_| cause superscripting and subscripting. As in TEX, they
apply to the next character or group, so sugar would be entered
`|C_6H_12O_6|', for instance. |Out-hershey| attempts
to use a smaller size
when displaying a subscript (actually two units smaller). If this
is not possible, it will try to use a smaller stroke set in the
same family. By now we're getting real desperate, so |Out-hershey|
just makes the current font as small as possible.
- All usual symbols, and many others, are available as
``|||〈mnemonic〉''.
If this sounded too theoretical, see the last chapter, containing a few examples.
A few differences exist between |out-hershey| and |out-text|: |out-hershey|
works only with one text justification setting, |'left 'bottom|. No special
care is given to enforce these settings, as they are by far the most
useful and common ones. Characters such as `|^|' and `|_|' must be prefixed
by a `|||', as they have a TEX meaning.