Concepts4

Line sweep (plane sweep) is a technique that processes geometric objects by moving an imaginary line and handling events in sorted order.

A line can be represented by two points, a point with a direction vector, or the general form ax + by + c = 0, and these forms are interconvertible.

The convex hull is the smallest convex polygon that contains all given points, like a rubber band snapped around nails on a board.

Point-in-polygon decides whether a point lies outside, inside, or on the boundary of a polygon.