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Re: How can I check for the existence of a glyph in TeX?



>At 05:50 PM 9/14/98 +0200, Lars Hellström wrote:
>
>>Alan Jeffrey wrote:
>
>>>On some systems (notably MacOs) whether a glyph exists or not depends on
>>>which driver you use (eg PostScript drivers have access to all glyphs,
>>>but QuickDraw drivers don't).  So the notion of `missing glyph' has to
>>>be put off to the driver in some cases.
>
>>AFSIK it's not really a matter of whether the drivers can access all glyphs
>>or not, but rather a matter of which glyphs are included in the fonts. Mac
>>fonts are (quite logically in most circumstances) usually set up to match
>>Apple's extension of 7-bit ASCII, not Adobe's, so some glyphs in the Adobe
>>set might not be included.
>
>The fonts themselves are identical.

Not in my experience they're not.

>  Adobe text fonts have 228 `standard'
>glyphs.  You can convert the actual font file from Mac to PC format back
>and forth without losing anything.  The text font does have all those
>glyphs --
>on any platform.   A stand-alone PS driver like DVIPS can trivially get at
>all 228 if it wants to (if DVIPS could understand the Macintosh Type 1 font
>file format).

It's a nice theory; what about the point that Mac founts often have glyphs
that don't exist in normal founts (encoded or otherwise): things like pi,
sigma, delta, rabbit, apple, candle, and so on?

[snip]

>Clearly the `right' solution is for the DVI viewer to work around the
>operating system
>limitation and allow access to all 228 standard characters.  Why should one be
>prevented from using ff, ffi,ffl ligatures on the Mac if the font has them
>(e.g. the
>Lucida Bright fonts) just because Mac standard roman encoding doesn't
>include those?

Because it's difficult to work around the OS, obviously.  If it were an
easy job, lots of dvi drivers other than Y&Y's would be able to do it.  As
it is, I gather that no (free|share)ware MS-Windows dvi driver (aside from
dvips) can even do re-mapping; and while OzTeX can manage re-mapping, it
can't do re-encoding (unless it uses dvips).

Rowland.