Recently I discovered that the few fonts I use are often lacking the different unicode characters for the different typographic spacings like EN space, EM space, thin, thick, mid, hair, etc.
I was wondering why, I don't really mind adding these myself but it's still annoying since my DTP app does not have this layout feature.
So is it:
-Lazyness?
-Practical reasons?
-Historical reasons?
I'd like your knowledgeable input on that. :)
Thanks!
Since regular old PostScript Type 1 fonts only had one space, and three dahes - hyphen, en dash, and em dash - when building OpenType fonts, it was not immediately apparent that one could add a dozen space and dash glyphs which already had Unicode indices. (At least, that's how it was for me; my last three releases have all of the spaces (and dashes) you mention.) There are so many great and sexy glyphs one can add to one's fonts, that one might overlook the basic and useful ones.
So, the answer to you question is probably ignorance due to historical precedent. Practically, there is absolutely no problem adding the extra glyphs, and it takes mere seconds, so laziness is no excuse.
Although one could put such things in the font, unless your DTP app is smart enough to know that they are spaces, it will treat them all as non-breaking.
If the DTP app is smart enough to know they're spaces, it's smart enough to just use those codepoints as control characters and not require them to be present in the font. It's not like they vary from font to font, anyway.
I disagree with Chester's comments - we were well aware that there were these extra spaces, and I was arguing for putting them in Adobe OpenType fonts back in the late '90s, but I got outvoted for the reasons listed above.
Regards,
T
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