OptionalhintingThe pixel sizes to capture hinted widths at, which are what make widths match Excel's, or
false for none.
OptionalsourceThe font file's name, recorded in the tables so a copy kept beside them can be found again.
OptionalfilterDecides per face, before the costly part, whether to capture it.
OptionalonCalled as each face is captured: for progress, since a face takes about a second.
Options for captureTables.