On Wed, 7 Oct 2015 16:50:25 +0300 Nikolay Sivov <bungleh...@gmail.com> wrote:
> In general foolproof solution > I think is to treat clusters as a whole and render whole cluster with > same rendering style (like fill pattern, color or whatever). Remember, you are far more important than the user, and should therefore do what is easier from your point of view and works well with European languages. Speaking as a non-native part-time user of a truly complex Indic script, it would be far more helpful to allow contiguous runs of codepoints be selected than to treat clusters as indivisible. If you could arrange for selected characters to be distinguished, and otherwise treated as normal, so much the better. I'd rather the cluster distorted horribly as I moved the cursor through than not to be able to position the cursor within a cluster, the current compromise. In Arabic, the shape of the consonant skeleton can be affected by whether vowel marks are present, so it is legitimate for selection or highlighting to alter the shape. Indic characters are more complicated. Multipart vowels may bracket the (multi-)consonant syllable offset, but it would still be pleasanter to be able to select the vowel without the preceding consonant(s). However, it is difficult to highlight the vowel in such a case without having a run boundary between the consonant and the vowel. Now, one could use a special font with coloured glyphs for most cases so as to highlight the vowel, but highlighting the second consonant of a geminate pair would get tricky - you'd need a special feature for each boundary position. Coloured glyphs would also address issues with ligatures. In principle, the GDEF table should record the horizontal boundaries of their positions, but such data may be lacking, for Microsoft ignores it and just spaces the internal boundaries evenly. Sometimes of course, the components are at different vertical positions rather than at different horizontal positions. Richard. _______________________________________________ HarfBuzz mailing list HarfBuzz@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/harfbuzz
