"""

    Space invaders - without killing aliens :)
    Code Toolkit: Python, Fall 2020
"""


global fighterX
fighterX = 350

global bulletY
bulletY = -5

def setup():
    size(700, 800)
    global swarmX, swarmY
    global swarmXDirection
    
    swarmX = 100
    swarmY = 100
    swarmXDirection = 2


def draw():

      global swarmX, swarmY, swarmXDirection, bulletY
      
      background(0)

      # Draw swarm of aliens with a nested loop
      noStroke()
      i = 0
      while i < 10:

          j = 0
          while j < 5:

              fill(100, 100, 255)
              rect( swarmX + i * 40, swarmY + j * 80, 20, 40)

              j = j + 1

          i = i + 1


      # Draw fighter ship
      fill(150)
      noStroke()
      triangle( fighterX, 650, fighterX+25, 700, fighterX-25, 700)


      # Draw bullet
      stroke(255, 255, 150)
      strokeWeight(5)
      line(fighterX, bulletY, fighterX, bulletY-25)


      # Move alien swarm
      swarmX = swarmX + swarmXDirection

      # Check alien swarm direction for "bounce" 
      if swarmX > 200:
          swarmXDirection = -2
          swarmY = swarmY + 2

      if swarmX < 100:
          swarmXDirection = 2
          swarmY = swarmY + 2

      # Move bullet
      bulletY = bulletY - 2


def keyPressed():
    
    global bulletY, fighterX

    if key == ' ':
        bulletY = 625

    if key == 'a':
        fighterX = fighterX - 2

    if key == 'd':
        fighterX = fighterX + 2