> Date: Wed, 18 Apr 2012 07:16:17 +0100 > From: [email protected] > To: [email protected] > Subject: Re: [HarfBuzz] A problem in thai shaper > > On 18/4/12 02:22, Behdad Esfahbod wrote: > > On 04/17/2012 06:47 PM, Khaled Hosny wrote: > >> On Tue, Apr 17, 2012 at 05:10:37AM +0200, Khaled Hosny wrote: > >>> On Mon, Apr 16, 2012 at 09:08:49PM -0400, Behdad Esfahbod wrote: > >>>>> Problem 2: > >>>>> > >>>>> When there is no consonant exist, the dotted circle should be inserted > >>>>> as base > >>>>> character. The logic should be the first step for the shaping engine to > >>>>> find > >>>>> the invalid combing marks. Refer to > >>>>> http://www.microsoft.com/typography/otfntdev/thaiot/shaping.aspx#comb > >>>> > >>>> Right. We do not handle invalid combining marks yet. That's something I > >>>> want > >>>> to do at some point but it's not high priority. > >>> > >>> I don't know about Thai, but the handling of "invalid" Arabic combining > >>> marks in Uniscribe is completely brain dead and a real PITA and I'd > >>> really like not to see HarfBuzz going there, a shaping engine is not a > >>> spell checker and should not enforce any input pattern. > >>> > >>> http://www.microsoft.com/typography/OpenType%20Dev/arabic/shaping.mspx#invalid > >> > >> Incidentally, I came across this Typophile post, which is one example of > >> why this "invalid" mark handling is not really a good idea: > >> http://typophile.com/node/92130 > > > > Interesting. I'm undecided about this as of now. > > Just adding my vote in favor of Khaled's position. > > The shaping engine should not attempt to enforce rules such as "only one > vowel mark on each consonant" or "nukta cannot apply to vowels" (IIRC, > MS may have relented on that one) or "the vowel mark must precede the > tone mark", etc. That's the role of a (language-specific) spell-checker. > > JK If shaping engine not attempt to enforce rules as your comments, it is necessary to anaylze the syllable of indic, because this belong to (language-spefic), the shaping engine only need apply all the feature that set by user. The user need analyze the syllable and decide to apply which feature should be applied. I don't think that is a good idea. not each of user is doing for a editor so we can't expect each of user is a language expert. The editor can be used to check the word or other someting, but not the atom element (example the syllable of indic or thai). Br, Dean > _______________________________________________ > HarfBuzz mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/harfbuzz
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