1. A method comprising: tracking limb motion of a user, the tracking comprising obtaining multiple images of the limb each having a rectangular frame; determining, based on the tracked limb motion, a range of movement of the limb inside the rectangular frame, the range of movement being elliptical, a rounded rectangle or circular; mapping coordinates of a location (P) of the limb in the range of movement to coordinates of a location (P′) in a bounding rectangle of the range of movement, by: (a) passing a line (CB) from a center (C) of the range of movement, through the location (P) of the limb in the range of movement, until a point (B) on a border of the bounding rectangle, wherein the line (CB) intersects with the range of movement at a point (A), (b) setting the coordinates of P′ such that P′ is on the line (CB) and such that CP′/CB equals CP/CA; and mapping the coordinates of P′ to target coordinates, and displaying an icon on a computer monitor at the target coordinates.