Introduction
The javalib world libraries provice a novice-appropriate environment for the design of graphics-based interactive games with a timer control, key events, mouse clicks, and, optional musical background and sound effects.
The programmer designs the game actions as the changes in the current game scene in response to the timer, key, or mouse event, and designs the display of the game scene (composed from the background and the game objects). All methods that define the game actions can be fully tested before the game is launched. All displays of the game scene can be verified and shown before the game is launched. The programmer sees only the model of the game and the view of the game (but even this only at the highest conceptual level) — the intricacies of the control are provided by the libraries.
The games can be converted to Java Applets with only a minimal additional work (mainly providing a wrapper WorldApplet class and modifying the model .html file with the information that describes the programmer’s game.
The design of these libraries is based on the libraries in DrRacket and its teaching languages that support the text How to Design Programs, 2nd Edition.
Here is a picture of a simple game where a shark lures on the left, controlled by the up and down keys trying to eat some fish from a school of fish swimming towards him. (Here the shark has died of starvation, not catching enough fish):
