Fetches the HarfBuzz.glyph_extents_t data for a glyph ID
in the specified font, with respect to the origin in
a text segment in the specified direction.
Calls the appropriate direction-specific variant (horizontal
or vertical) depending on the value of direction.
Fetches the HarfBuzz.glyph_extents_t data for a glyph ID in the specified font, with respect to the origin in a text segment in the specified direction.
Calls the appropriate direction-specific variant (horizontal or vertical) depending on the value of
direction.