You control the program with your mouse. At any time you can click on the right side of the sweep-line to add a point. Below follows an explanation of the various buttons and checkboxes. Buttons Checkboxes Suspend Halt the incremental movement of the sweep-line. Resume Continue the incremental movement.
Next event Move the sweep-line to the next event point, including circle event points.
Next pixel Move sweep-line a single pixel. Clear Clear the canvas. Restart Move the sweep-line to the extreme left and restart tracing of the Voronoi diagram. If you draw a perfect circle of points all the zones should meet in the center of this circle. Now try to spoil this feature by adding a point in the middle of the circle.