On Wed, 9 Jan 2002, Bill Medland wrote:
> While I was working on the DrawText functions over the past many months I > started wondering about when it would fail. (I'm pedantic and such things > fascinate me!). The main concern I have is how to walk a W string > correctly. For example while "ellipsifying" text we will need to "move the > pointer to the previous character" which is currently done by decrementing > the pointer by 1. But from what I currently understand that won't work if > there are surrogate pairs. If you're concerned about that, surrogate pairs are the least of your worries. You should also be concerned about Unicode combining (or composite) characters. I think they might be identified with ctypes C3_NONSPACING and C3_DIACRITIC and that kind of stuff... > 1. Does anyone know under what circumstances CharNextW isn't +1 (apart from > when pointing at the terminating 0) Have you tried low surrogate followed by high surrogate, on a Microsoft OS recent enough that Microsoft *might* have thought about preparing it for dealing with surrogates? > 2. Is e.g. XP really using UTF-16 or is it actually still UCS2? I don't know. But it probably ought to be UTF16. > 3 Have we thought about how we should handle walking along a W string (in a > fashion that doesn't reduced the speed to a crawl). I guess that in the > short term I am expecting some sort of macro or inline. With p++, perhaps? There aren't very many circumstances where that is going to be a problem (where unicode composite characters are not also), is there?
