# Burning Ship Fractal for CodeSkulptor3

import simplegui

# dimensions of screen are in pixels
width  = 150
height = 110
# scale, pixels per unit on complex plane
scale = 40
# offsets
# distance of (0, 0) from the top left of the drawing area
# in units on complex plane
xoff = 2.5
yoff = 2

# Handler to draw on canvas
def draw(canvas):
  lim = 200 # iteration limit
  # iterate over every pixel
  for x in range(width):
    for y in range(height):
      i = 0
      x1 = x / scale - xoff
      y1 = y / scale - yoff
      a = 0
      b = 0
      while (a*a+b*b) < 4 and i < lim:
        i += 1
        c = abs(2 * a * b)
        a = (a*a-b*b) + x1
        try:
          b = c + y1
        except Exception as e:
          print(repr(e))
          i = lim
      colour = (i >= lim and 'black' or
          'hsl(' + str(i*1.5) + ', 100%, 50%)')
      if not colour == 'black':
          canvas.draw_point([x, y], colour)
  print("Finished drawing")

def main():
  # Create a frame and assign callbacks to event handlers
  frame = simplegui.create_frame("Burning Ship", width, height)
  frame.set_draw_handler(draw)

  # Start the frame animation
  frame.start()

main()