Moon Patrol

Moon Patrol is a tiny JavaScript game created for the Practice in Video Games course at New Bulgarian University

Team

• Project Manager: Dimitar Petrov
• Lead Gameplay Programmer: Spas Kalinov
• Lead Graphic Designer: Lucy Dragodanova

Technical Documentation

Game Area

The gameArea variable is a HTML 5 canvas. Most important methods associated with it:

• gameArea.mainMenu() - instantiates the canvas with the given dimensions and loads the user interface;
• gameArea.start() – sets up the Keyboard Event Listeners (used for user input);
• gameArea.clear() – deletes everything drawn on the canvas;
• gameArea.stop() – stops updating the canvas;
• updateGameArea() – the main update method of the game. Takes care of updating the canvas, moves the player and enemy/obstacle sprites, checks for collisions between player, enemies/obstacles and bullets, handles keyboard input; if the player is dead, invokes the gameArea.stop() method.

  Game Loop

  This is the central code of the game, split into three different parts: initialize, update and draw:

• initialize – the startGame() method. It invokes the gameArea.start() method and initializes the main game components – player sprite, background elements, ground line, HUD, etc.;
• Update and Draw – the gameArea.update() method; the game area is updated once every 10th millisecond (100 times per second). It also takes care of clearing the redrawing the game components on the canvas.

  Component

  The main object constructor is called component. Components have properties and methods to control their appearances and movements. Everything in the game is a component – the player, enemies and bullets, the background elements and the HUD.

  Player Movement

  The player’s movement logic is handled in the Update phase by invoking the moveLeft(), moveRight() or jump() methods.

  Shooting

  The player’s shooting logic is handled in the Update phase by invoking the shoot() method.

  Difficulty Scaling

  The difficulty scaling logic is implemented in the adjustDifficulty() method.

  Sounds and Music

  The sounds and music playback logic is implemented in two methods: music() and playSound(soundType).