controls.txt

Use of the Mouse:
  - Press and Hold Left-Mouse Button to spawn a Ball
  - While holding the Button, drag the Mouse opposite to the direction
    in which you want to launch the Ball
  - Click Left-Mouse Button on a Ball to view information about it
  - Click Right-Mouse Button while drawing a Ball to cancel its release
  - Click Right-Mouse Button on a Ball to remove it from the screen
* Speed of the Ball will be proportional to the drag distance
Use of the Keyboard:
  - Press 'B' to toggle the visibility of the Box/Region where Balls
    can be spawned
  - Press 'C' to launch a menu to change Gravitational Acceleration
  - Press and Hold 'D' to change density of the Balls being spwaned
  - Press 'E' to launch a menu to change the Coefficient of Restitution
  - Press 'G' to toggle Gravity, i.e. switch Gravity ON and OFF
  - Press 'P' to Pause and Resume the Simulation
  - Press 'R' to remove all Balls from the screen
  - Press 'V' to toggle the visibility of velocity vectors of the Balls
  - Press Arrow Keys to change the direction of Grvaity