[ft] How to determine which Unicode blocks a True Type font supports?

[DK]

Is there a way using FreeType on Windows to determine:

1.       Which Unicode blocks (as per http://unicode.org/ V8.0.0) the font supports?

2.       In the blocks it supports, how many of the characters are supported?

 

For example, TrueType font Symbola all 48 characters of Unicode block “Miscellaneous Mathematical Symbols-A” (U+27C0 – U+27EF), all 116 characters in the Unicode block “Alchemical symbols” (U+1F700 – U+1F77F) but only 4 characters of Unicode block “Latin Extended-E” (U+AB30 - U+AB65).

 

Note: Windows works with surrogates and not the Unicode integer value for characters above 0xFFFF (i.e. not in the BMP).

 

I assume one has to process the cmap table but this does not seem as easy as I had hoped.  It doesn’t help that the cmap seems to be big endian and Windows is little endian!

 

Many thanks.