Peter Kirk <peter dot r dot kirk at ntlworld dot com> wrote: >> Or it may not. It may be a deficiency in the level of Unicode >> support afforded by the fonts and rendering engines. ... > > If there are such deficiencies in fonts and rendering engines which > purport to be Unicode compliant, that suggests a lack of clarity in > the standard which should be rectified.
I wish I had a dollar for every "Unicode-compliant" font, rendering engine, or other software that was in some way less compliant than advertised. Only a fraction of the non-compliances are traceable to ambiguities or deficiencies in the Unicode Standard. >> ... It may simply reflect a difference between your "requirements" >> and what the standard promises, and doesn't promise. > > If Unicode doesn't promise what I require, surely it is at least > reasonable for me to ask on this list whether it ought to be extended > or clarified to do so. The UTC may choose not to make any changes, but > I don't see why they shouldn't even be asked to. Absolutely, you are allowed to ask. Go ahead. I wasn't trying to prevent questions from being asked, only trying to state why I think the problem is out of scope for Unicode. >> The standard doesn't say anything about width in this case. It >> leaves it up to the display engine, which is as it should be. > > The standard does say, section 2.10 of 4.0, that "In rendering, the > combination of a base character and a nonspacing character may have a > different advance width than the base character itself". I apologize for missing this reference. > And any intelligent typographer will realise that this "may" is a > "must", with regular character designs but not of course in monospace, > in some cases like the example given of i with circumflex. This > sentence applies to spaces with diacritics as space is a base > character, as we have been informed. The subsection of 2.10 entitled > "Spacing Clones of European Diacritical Marks" (by the way, why > "European" when the text appears to apply to all diacritical marks?) > should suggest to any intelligent typographer that the sequence space, > diacritic is intended to be spaced as the diacritic and not as a > space, but it would help for this to be clarified as not all > typographers are very intelligent and some may not be aware that this > space has actually lost most of the properties of a space e.g. line > breaking and is being used only "By convention". Like Freud's cigar, sometimes a "may" is just a "may." And I suspect the phrase "any intelligent typographer" MAY generate some flak from typographers on this list who consider themselves "intelligent enough" yet have a different opinion. I'm not a typographer (intelligent or otherwise), but I'm having a tough time seeing how Section 2.10 *requires* fonts and rendering engines to give a space-plus-combining-diacritic combination the exact minimum width of the diacritic alone, or to leave equal space before and after such a combination. All I think it is saying is that, for example, the combination i-plus-tilde may be wider than i alone, because tilde is wider than i. >> When the specific alignment of isolated glyphs is important to me, I >> use markup. I'm a big supporter of plain text, as many members of >> this list know, but the exact spacing of isolated combining marks >> seems like a layout issue to me. > > OK, what kind of markup should I use, in any well-known markup > language, to ensure that an isolated diacritic is centred in the space > between the words before and after it? All right, you've got me there. I'll have to think about it. But I still think this is a layout problem, a problem having to do with glyphs and not characters. -Doug Ewell Fullerton, California http://users.adelphia.net/~dewell/
