def setup
  background(220)
  img = createImage(66, 66)
  img.loadPixels
  (0...img.width).each do |i|
    (0...img.height).each do |j|
      img.set(i, j, color(0, 90, 102))
    end
  end
  img.updatePixels
  image(img, 17, 17)
end

def setup
  background(220)
  img = createImage(66, 66)
  img.loadPixels
  (0...img.width).each do |i|
    (0...img.height).each do |j|
      img.set(i, j, color(0, 90, 102, (i % img.width) * 2))
    end
  end
  img.updatePixels
  image(img, 17, 17)
  image(img, 34, 34)
end

def setup
  background(220)
  pink = color(255, 102, 204)
  img = createImage(66, 66)
  img.loadPixels
  d = pixelDensity
  halfImage = 4 * (img.width * d) * (img.height / 2 * d)
  0.step(halfImage, 4) do |i|
    img.pixels[i]     = red(pink)
    img.pixels[i + 1] = green(pink)
    img.pixels[i + 2] = blue(pink)
    img.pixels[i + 3] = alpha(pink)
  end
  img.updatePixels
  image(img, 17, 17)
end