<Digital differential line algorithm>=
public void dda(int x0, int y0, int x1, int y1) {
  int x = x0;
  int y = y0;
  plot (x, y);
  while (x < x1) {
    x = x + 1;
    y = y + m;
    plot (x, Math.floor(y+0.5));
  }
}