Dear list, I’m experiencing a weird issue with optical bounds in OpenType.
Here you have the mandatory sample (font avaiable at https://gitlab.com/ousia/greek-lfbd/raw/master/TypographicaOStandard-Regular.otf): \startluacode fonts.handlers.otf.addfeature { name = "leftbounds", type = "single", data = { Ἀ = { -32, 0, -32, 0 }, Ἁ = { -32, 0, -32, 0 }, Ἂ = { -70, 0, -70, 0 }, Ἃ = { -70, 0, -70, 0 }, Ἄ = { -50, 0, -50, 0 }, Ἅ = { -50, 0, -50, 0 }, Ἇ = { -42, 0, -42, 0 }, Ἆ = { -42, 0, -42, 0 }, Ἠ = { -212, 0, -212, 0 }, Ἡ = { -212, 0, -212, 0 }, Ἢ = { -258, 0, -258, 0 }, Ἣ = { -258, 0, -258, 0 }, Ἥ = { -286, 0, -286, 0 }, Ἤ = { -286, 0, -286, 0 }, Ἦ = { -246, 0, -246, 0 }, Ἧ = { -246, 0, -246, 0 }, Ὧ = { -196, 0, -196, 0 }, } } \stopluacode \enabletrackers[fonts.protrusion] \definefontfeature[default][default] [script=greek, protrusion=quality, opbd=yes] \definefontfeature[leftbounds][leftbounds=yes] \showframe \setuplayout[page] \definefontfamily[mainface][rm][Typographica Old Standard] \definefontfamily[mainface][tt][Latin Modern Mono] \setupbodyfont[mainface, 300pt] \setupalign[hanging] \startbuffer \ifnum\pagenumber=1{\ttxx opbd}\else{\ttxx -opbd}\fi\page Ω\\ Ὧ\\ Α\\Ἀ\\Α\\Ἁ\\Α\\Ἂ\\Α\\Ἃ\\Α\\Ἄ\\Α\\Ἅ\\Α\\Ἆ\\Α\\Ἇ\\ Ἠ\\Η\\Ἡ\\Η\\Ἢ\\Η\\Ἣ\\Η\\Ἤ\\Η\\Ἥ\\Η\\Ἦ\\Η\\Ἧ\\Η \stopbuffer \starttext \getbuffer \setupalign[nothanging] \feature[+][leftbounds] \getbuffer \stoptext OpenType optical bounds are read from the font right: fonts > protrusions > left factor 1, right factor 1 fonts > protrusions > setting left using lfbd fonts > protrusions > lfbd -> 0.032 Ἀ (U+01F08) fonts > protrusions > lfbd -> 0.032 Ἁ (U+01F09) fonts > protrusions > lfbd -> 0.070 Ἂ (U+01F0A) fonts > protrusions > lfbd -> 0.070 Ἃ (U+01F0B) fonts > protrusions > lfbd -> 0.050 Ἄ (U+01F0C) fonts > protrusions > lfbd -> 0.050 Ἅ (U+01F0D) fonts > protrusions > lfbd -> 0.042 Ἆ (U+01F0E) fonts > protrusions > lfbd -> 0.042 Ἇ (U+01F0F) fonts > protrusions > lfbd -> 0.196 Ὧ (U+01F6F) fonts > protrusions > lfbd -> 0.246 Ἧ (U+01F2F) fonts > protrusions > lfbd -> 0.286 Ἦ (U+01F2E) fonts > protrusions > lfbd -> 0.246 Ἥ (U+01F2D) fonts > protrusions > lfbd -> 0.258 Ἤ (U+01F2C) fonts > protrusions > lfbd -> 0.286 Ἣ (U+01F2B) fonts > protrusions > lfbd -> 0.258 Ἢ (U+01F2A) fonts > protrusions > lfbd -> 0.212 Ἡ (U+01F29) fonts > protrusions > lfbd -> 0.212 Ἠ (U+01F28) I’m afraid that they aren’t applied accurately. The same values are used with the property "leftbounds" and they are perfect in that feature. Shouldn’t be the output from both methods be exactly the same? In all glyph pairs, both accented and unaccented glyphs should end in exactly the same point. I think this may be a bug, although I may be missing something. Many thanks for your help, Pablo -- http://www.ousia.tk ___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________
