# Simple animation showing pixel vs subpixel accuracy.
# by Miloslav Ciz, released under CC0 1.0

from PIL import Image
import math

SCALE = 8

FRAMES = 64

RESOLUTION = (32,16)

img = Image.new("RGB",(RESOLUTION[0] * SCALE,RESOLUTION[1] * SCALE),"white")

pixels = img.load()

def drawLine(p0, p1):
  slope = (p1[1] - p0[1]) / float(p1[0] - p0[0])

  for i in range(int(p1[0] - p0[0] + 1)):
    x = round(p0[0] + i) * SCALE
    y = round(p0[1] + i * slope) * SCALE

    for b in range(SCALE):
      for a in range(SCALE):
        pixels[x + a,y + b] = (0,0,0)

for f in range(FRAMES):
  img.paste((255,255,255),(0,0,img.size[0],img.size[1]))

  t = f / float(FRAMES) * math.pi * 2

  x0 = 3
  x1 = 13

  y0 = 8 + math.sin(t) * 3
  y1 = 7 + math.cos(t)

  x0 += (RESOLUTION[0] / 2)
  x1 += (RESOLUTION[0] / 2)

  drawLine((x0,y0),(x1,y1))

  x0 -= (RESOLUTION[0] / 2)
  x1 -= (RESOLUTION[0] / 2)

  y0 = round(y0)
  y1 = round(y1)

  drawLine((x0,y0),(x1,y1))

  for i in range(RESOLUTION[1] * SCALE):
    pixels[int(RESOLUTION[0] * SCALE / 2),i] = (0,0,0)

  img.save("out" + str(f).zfill(2) + ".png")