Class SnakeGame

snake-dqn/snake_game.js:49–325

}

export class SnakeGame {
  /**
   * Constructor of SnakeGame.
   *
   * @param {object} args Configurations for the game. Fields include:
   *   - height {number} height of the board (positive integer).
   *   - width {number} width of the board (positive integer).
   *   - numFruits {number} number of fruits present on the screen
   *     at any given step.
   *   - initLen {number} initial length of the snake.
   */
  constructor(args) {
    if (args == null) {
      args = {};
    }
    if (args.height == null) {
      args.height = DEFAULT_HEIGHT;
    }
    if (args.width == null) {
      args.width = DEFAULT_WIDTH;
    }
    if (args.numFruits == null) {
      args.numFruits = DEFAULT_NUM_FRUITS;
    }
    if (args.initLen == null) {
      args.initLen = DEFAULT_INIT_LEN;
    }

    assertPositiveInteger(args.height, 'height');
    assertPositiveInteger(args.width, 'width');
    assertPositiveInteger(args.numFruits, 'numFruits');
    assertPositiveInteger(args.initLen, 'initLen');

    this.height_ = args.height;
    this.width_ = args.width;
    this.numFruits_ = args.numFruits;
    this.initLen_ = args.initLen;

    this.reset();
  }

  /**
   * Reset the state of the game.
   *
   * @return {object} Initial state of the game.
   *   See the documentation of `getState()` for details.
   */
  reset() {
    this.initializeSnake_();
    this.fruitSquares_ = null;
    this.makeFruits_();
    return this.getState();
  }

  /**
   * Perform a step of the game.
   *
   * @param {0 | 1 | 2 | 3} action The action to take in the current step.