Asteroids Game in Racket (2021)

The article discusses the implementation of the classic Asteroids game using the Racket programming language, focusing on creating a game engine and a physics engine within approximately 1000 lines of code. The game involves controlling a spaceship to shoot and destroy asteroids while avoiding collisions. The game engine manages a scene composed of actors, which represent game entities. It includes functions for adding and removing actors, updating their states, and handling user input. Each actor must implement methods for painting itself, updating its state, and responding to keyboard events.

The game window is created using a class that handles user interface events, while a canvas object allows for drawing on the window. The game loop is crucial for maintaining a consistent frame rate, updating the scene, and redrawing the canvas. The physics engine simulates the movement of rigid bodies, which are represented as circles for collision detection. It tracks properties such as position, velocity, and acceleration, and uses vectors to manage two-dimensional space.

The article emphasizes that while the physics engine provides basic movement and collision handling, it does not fully simulate real-world physics. The implementation is designed to be efficient and straightforward, allowing for a playable version of Asteroids without external libraries, showcasing the capabilities of Racket for game development.