The service where I uploaded the images is temporarily down, so I uploaded them to <http://www.freeimagehosting.net/newuploads/tm8kc.png> and <http://www.freeimagehosting.net/newuploads/6j9r8.png>
-- Tom Il giorno 07/ott/2013, alle ore 01.13, [email protected] ha scritto: > I am just beginning to try Harfbuzz, but I am writing to you because I think > that I might have found incorrect behavior when I have both a contextual > chained substitution and a contextual chained positioning. > > The problems occur when I have the following two rules: > 1 Substitute ["e"] with ["o" "e"] when preceded by an "a" (context: { ["a"] > | } ) > 2 Position the mark ["gravecomb"] anchoring it to the ["e"] when the mark is > followed by an "i" (context: { | "i" } ) > > What I think I should see when I type ["a" "e" "gravecomb" "i" "e" > "gravecomb" "i" ] should be something like [aoèièi] > What I see is more like [aoeˋièi] (the first "gravecomb" is not anchored to > the "e") > I used the characters "a", "e", "i", "o", "gravecomb" (U+0300) but the > problem is not specific to those characters and persists even in right to > left scripts. I found while examining the font SBLHebrew and the string > "קוָ֣". > > I built a very minimal font that reproduces this problem with the latin > characters I used for the example. I put online the Fontforge source > <https://www.dropbox.com/s/a78cypqv3jgmaex/prova.sfd> and the ttf > <https://www.dropbox.com/s/5hq1c5mdg4isvzo/minimal.ttf> > > However, the fact that the problem is reproduced almost exactly on Uniscribe, > and even in the Proofing tool of MS VOLT makes me wonder if it is a bug or > not. The problem is not present on the shaping system of ConTeXt Mark IV and > on Apple's TextEdit, so it is even more mysterious for me. > > I also put the link of the (IMHO correct) rendering of Fontforge > <http://s23.postimg.org/8w44n9b3v/Screenshot_from_2013_10_07_00_55_45.png> > and of the rendering of hb-view > <http://s14.postimg.org/p02lzc29t/Screenshot_from_2013_10_07_00_58_32.png> > (in order to render it with "hb-view --language=dflt --features="calt,kern" > '/home/mint/Desktop/minimal.ttf' aèièi", be aware that the è is composed of > two characters, U+0065 and U+0300, because the software tends to convert > this sequence to the single U+00E8 character). The problem is not with the > spacing (in my font the "gravecomb" has nonzero width, but it's a mark, so > its width is somewhat undefined) but with the fact that the first accent is > not attached to the first "e". > > -- > Tom _______________________________________________ HarfBuzz mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/harfbuzz
