Instructions
Click anywhere on the display in the upperleft corner to select an
endpoint on the screen. Click the "Left" or "Right" buttons to have the
point on the screen move in the corresponding direction, and press "Stop"
to stop the movement. The "Block Left Slit" and "Block Right Slit" buttons
can be used to open and close the left and right slits respectively. The
"Closer Slits" and "Farther Slits" buttons can be used to change the distances
between the slits by either clicking once or clicking and holding. Finally,
the "Show Path Vectors" button toggles on and off whether the individual
path vectors will be displayed or just the final vector for the process.