box-o-sand/intro-to-crafty/src/game.js

Game = {
  map_grid: {
    width: 24,
    height: 16,
    tile: {
      width: 16,
      height: 16
    }
  },

  width: function() {
    return this.map_grid.width * this.map_grid.tile.width;
  },

  height: function() {
    return this.map_grid.height * this.map_grid.tile.height;
  },

  start: function() {
    Crafty.init(Game.width(), Game.height());
    Crafty.background('rgb(249, 223, 125)');

    for (var x = 0; x < Game.map_grid.width; x++) {
      for (var y = 0; y < Game.map_grid.height; y++) {
        var at_edge = x == 0 || x == Game.map_grid.width - 1 || y == 0 || y == Game.map_grid.height - 1;

        if (at_edge) {
          Crafty.e('Tree').at(x, y);
        } else if (Math.random() < 0.06) {
          Crafty.e('Bush').at(x, y);
        }
      }
    }
  }
}