To add a point, just click in the applet. To remove a circle, hold down SHIFT
and click on it. To resize a circle, click on the center of the circle, hold
down CTRL, and move the mouse. To move a circle, just click on it and drag
it to its new position. Pushing the RESTART button will clear the applet
and let you put in new points.
Sorry about the artifacts, but that's the best we can get with an approximate
number system. If you get an artifact (like a misshapen power cell), grab
a nearby point and shake it around a little. Usually, that clears up the problems.
This little trick also draws in the Voronoi edges to infinity if
they're not already on the diagram.
The GUI was shamelessly stolen from the Voronoi diagram applet
at
http://www.cs.brown.edu/courses/cs252/proj/src/Spr96-97/cl/delaunay.html
, written by Conglin Lu.