returns (sync) the coordinates of point a in the frame rep (system of coordinates) if provided, otherwise in the svg coordinate system
First point or point name (or tag if name is empty) the line is going through
Optional
Same as params.rep when first parameter is a string. This second parameter is ignored if the first one is a params object.
returns (sync) the coordinates of point a in the frame rep (system of coordinates) if provided, otherwise in the svg coordinate system