Constructs a new face object from the specified blob and
a face index into that blob.
The face index is used for blobs of file formats such as TTC and
DFont that can contain more than one face. Face indices within
such collections are zero-based.
<note>Note: If the blob font format is not a collection, index
is ignored. Otherwise, only the lower 16-bits of index are used.
The unmodified index can be accessed via harfbuzz.global.faceGetIndex.</note>
Constructs a new face object from the specified blob and a face index into that blob.
The face index is used for blobs of file formats such as TTC and DFont that can contain more than one face. Face indices within such collections are zero-based.
<note>Note: If the blob font format is not a collection, index is ignored. Otherwise, only the lower 16-bits of index are used. The unmodified index can be accessed via harfbuzz.global.faceGetIndex.</note>
<note>Note: The high 16-bits of index, if non-zero, are used by harfbuzz.global.fontCreate to load named-instances in variable fonts. See harfbuzz.global.fontCreate for details.</note>