An MgCoordinateSystemGridTick object consists of a grid value, a tick location point in viewport coordinates, and a 2D unit direction vector. Position is the position of the tick mark on a grid or boundary line. The 2D unit direction vector is the direction of the line at the position given. In the case of a tick mark on a boundary line, since boundary lines are always maintained in the counterclockwise direction, the interior of the viewport will always be to the left of the direction vector.
An MgCoordinateSystemGridLineCollection is collection of MgCoordinateSystemGridLine objects. As manufactured, grid horizontal lines appear first in ascending order by grid value (easting in this case); followed by grid vertical lines in ascending order by grid value (northing in this case).
1.8.0 
