Rational Number Interface

The purpose of this window is to allow you to enter exact rational coordinates into McBilliards. The top right display shows a pair of rational numbers. This pair may or not coincide with the current selected in parameter space. There are 2 modes for selecting rational coordinates.
Once you decide on a mode to use, you have 3 ways to select a rational point in the parameter space. There is one other feature of the rational number interface. The grid button toggles the presence of a grid whose lines have rational equations. There is a pop-up window called the grids which allows you to make much fancier background grids. These grids are very useful for studying infinite families of billiard paths.