code: public void generatePixels( HashSet<Point> pix ) {
          // Reset all pixels to background
          for( int j = 0; j < height; ++j ) {
              for( int i = 0; i < width; ++i ) {
                  pixels[i][j] = BACKGROUND;
              }
          }
          convertToPixels(pix);
      }
docs: Generates a new 2D array of pixels from a hash set of
  foreground pixels.
  
  @param pix The hash set of foreground pixels.