Returns the index in the text storage for the first character associated with the given glyph.
- iOS 7.0+
- macOS 10.0+
- tvOS 9.0+
The index of the glyph for which to return the associated character.
The index of the first character associated with the glyph at the specified index.
If noncontiguous layout is not enabled, this method causes generation of all glyphs up to and including
glyph. This method accepts an index beyond the last glyph, returning an index extrapolated from the last actual glyph index.
In many cases it’s better to use the range-mapping methods,
glyph, which provide more comprehensive information.