code: function addAlignment(x, y) {
      var i;
  
      frameBuffer[x + width * y] = 1;
  
      for (i = -2; i < 2; i++) {
        frameBuffer[(x + i)     + width * (y - 2)]     = 1;
        frameBuffer[(x - 2)     + width * (y + i + 1)] = 1;
        frameBuffer[(x + 2)     + width * (y + i)]     = 1;
        frameBuffer[(x + i + 1) + width * (y + 2)]     = 1;
      }
  
      for (i = 0; i < 2; i++) {
        setMask(x - 1, y + i);
        setMask(x + 1, y - i);
        setMask(x - i, y - 1);
        setMask(x + i, y + 1);
      }
    }
docs: Enter alignment pattern. Foreground colour to frame, background to mask. Frame will be merged with mask later.