This Java applet is an interactive demo of a region quadtree for a set of points in the plane. To begin the demo, simply left click to add a point. Points will only be added if they are located inside the square and if they are not in the same position as an existing point.
Each point is randomly assigned one of seven colors in order to make it easier to identify the corresponding point in the quadtree structure. The quadtree is set up so that the points, in left to right order, represent the SW quadrant, the SE quadrant, the NW quadrant and the NE quadrant.