如何从表中获取字距调整对的值？

Question

我得到CGGlyph

let a = CTFontGetGlyphWithName(font, "A" as CFString)
let v = CTFontGetGlyphWithName(font, "V" as CFString)

我得到了表格的链接

let kernData = CTFontCopyTable(font, CTFontTableTag(kCTFontTableKern), CTFontTableOptions(rawValue: 0))

字距表

let kerningTable = CFDataGetBytePtr(kernData)