space-invaders.js

setBackdropColor('black')

var rocket = new Image({
  url: "./docs/images/rocket.png",
  width: 120, 
  height: 60,
  y: minY + 100,
  angle: UP
})

when(() => keysDown.includes('LEFT'), () => {
  rocket.x -= 5
})

when(() => keysDown.includes('RIGHT'), () => {
  rocket.x += 5
})

var enemies = []
for (var y = -3; y < 3; y++) {
  var row = []
  for (var x = -3; x < 3; x++) {
    var enemy = new Image({
      url: "./docs/images/space_ship.png",
      width: 30 * 2, 
      height: 17 * 2,
      x: (x * 60) - 100,
      y: (y * 50) + 200,
      rotationStyle: "NO ROTATE"
    })
    row.push(enemy)
  }
  enemies.push(row)
}

var flatten = a => a.reduce(
  ( acc, cur ) => acc.concat(cur),
  []
);

every(700, 'miliseconds', () => {
  var allEnemies = flatten(enemies)
  if (allEnemies.length > 0) {
    var leftMost = allEnemies.reduce((min, next) => next.x < min.x ? next : min , allEnemies[0])
    var rightMost = allEnemies.reduce((max, next) => next.x > max.x ? next : max , allEnemies[0])

    if (leftMost.x < minX || rightMost.x > maxX) {
      allEnemies.forEach(enemy => enemy.turnRight(180))
      allEnemies.forEach(enemy => enemy.y -= 10)
    }
    allEnemies.forEach(enemy => enemy.move(10))
  }
})