Fix a bug in generative_pattern

  hue = new int[width / 8][height / 8];

  saturation = new int[width / 8][height / 8];

  rand = new int[width / 8][height / 8];

  rand = new int[width / 8 + 1][height / 8 + 1];

  for (int i = 0; i < width / 8; i++){

    for (int j = 0; j < height / 8; j++){

      hue[i][j] = int(random(40, 60));