We expect to enhance truetype package to be able to render the position of Thai vowel and tone mark correctly

Todo

• truetype should be able to select an index of glyph by name which has not yet implemented here
  

which might lead into access post table from ttf file

an example of post table parser by rust https://github.com/RazrFalcon/ttf-parser/blob/439aaaebd50eb8aed66302e3c1b51fae047f85b2/src/tables/post.rs

• freetype must be able to pick a right glyph (vowel and tone mark) by the combination of the glyph ( AKA cluster ) which already mention in the reference document please see /example/thaiglyph ( tb67lemb.pdf, thaistd.pdf )

Reference

• TrueType table parsing http://stevehanov.ca/blog/?id=143
• better explanation of post table https://docs.microsoft.com/en-us/typography/opentype/spec/post
• TrueType parsing https://tchayen.github.io/ttf-file-parsing/
• Mac unicode mapping for Thai glpyh https://github.com/tallakt/codepagex/blob/master/unicode/VENDORS/APPLE/THAI.TXT