January 19th 2020
Compute a byte position at a particular point relative to the top left corner of a particular line
the standard custom layer context pointer
the id of the view who's layout will be measured
the line number of the line that serves as the relative starting point of the measurement
the point, in pixels, interpreted relative to the line's top left corner, that will serve as the query point
the byte index associated as the first byte of a character in the layout that is the closest to containing the query point on success, when the view exists and contains the line, zero otherwise
Line numbers are 1 based.
Equivalent to calling the buffer related function of the same name by deriving the buffer, width, and face from the view.