For two weeks, Leo coded obsessively. He implemented offside rules using a Linesman helper class. He coded a Referee that threw FoulException objects, which the main loop caught and turned into free kicks. He even added a rudimentary crowd noise class that played a .wav file of static mixed with a faint "Olé!" every time a pass completed.
The core was elegant. A Pitch class, a 2D array of Tile objects. A Ball with double x, y and a Vector velocity . Eleven Player objects on each side, each an instance of a complex hierarchy: Goalkeeper extends Player , Defender extends Player , Forward extends Player . They had states: RUNNING , STANDING , TACKLING , SHOOTING . They had AI—primitive at first, a simple decide() method that calculated the shortest path to the ball. java football game
It had started as a joke. A final project for Advanced Object-Oriented Programming: "Simulate any real-world system." His classmates chose traffic intersections, library catalogs, and a particle physics engine. Leo chose football. Not the American kind—the beautiful game. He called it GoalZone 1.0 . For two weeks, Leo coded obsessively