I have some code in an InDesign plug-in that iterates through all glyphs in a font and extracts the unicode value for the glyph by calling glyphUtils->GlyphToCharacter(font, glyph, &userAreaChar)
For the majority of glyphs there is a unicode value telling me which character this glyph represents. I am now working with Devanagari fonts where there are many glyphs which are Ligatures of combinations of many Devanagari unicode characters. Is there any way I can do a reverse lookup to find out which unicode characters, when combined, produces this glyphID?
Do I have to use glyphUtils->GetOTFAttribute and iterate through it to find which combination of unicode characters result in a particular glyphID? And what parameters should I use for GetOTFAttribute to get the ligature table?