January 19th 2020
Compute the byte position associated with the start of a particular character specified relative to the first character 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 relative character index of the query character, based at the first character of base line
the byte index associated with the start of the character specified by the the base_line and relative_character parameters on success, when the view exists and contains the base 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.