Convex Hull Algorithms - Planar Case

Planar Case

Consider the general case when the input to the algorithm is a finite unordered set of points on a Cartesian plane. An important special case in which the points are given in the order of traversal of a simple polygon's boundary is described later in a separate subsection.

If not all points are on the same line, then their convex hull is a convex polygon whose vertices are some of the points in the input set. Its most common representation is the list of its vertices ordered along its boundary clockwise or counterclockwise. In some applications it is convenient to represent a convex polygon as an intersection of a set of half-planes.