This class defines an upright rectangle.

public value class RectangleI
  Point A;
  Point B;

  RectangleI(int xA,
             int yA,
             int xB,
             int yB) {A.X = xA; A.Y = yA; B.X = xB; B.Y = yB;}

  RectangleI(Point ASet,
             Point BSet) { A = ASet; B = BSet; }


Point A is usually the upper-left corner of the rectangle and point B is usually the lower right corner of the rectangle.