bresenham algorithm

                                    function line(x0, y0, x1, y1) {
   var dx = Math.abs(x1 - x0);
   var dy = Math.abs(y1 - y0);
   var sx = (x0 < x1) ? 1 : -1;
   var sy = (y0 < y1) ? 1 : -1;
   var err = dx - dy;

   while(true) {
      setPixel(x0, y0); // Do what you need to for this

      if ((x0 === x1) && (y0 === y1)) break;
      var e2 = 2*err;
      if (e2 > -dy) { err -= dy; x0  += sx; }
      if (e2 < dx) { err += dx; y0  += sy; }
   }
}

                                    static void bresenham(int x1, int y1, int x2, int y2) 
    { 
        int m_new = 2 * (y2 - y1); 
        int slope_error_new = m_new - (x2 - x1); 
      
        for (int x = x1, y = y1; x <= x2; x++) 
        { 
            System.out.print("(" +x + "," + y + ")\n"); 
  
            // Add slope to increment angle formed 
            slope_error_new += m_new; 
  
            // Slope error reached limit, time to 
            // increment y and update slope error. 
            if (slope_error_new >= 0) 
            { 
                y++; 
                slope_error_new -= 2 * (x2 - x1); 
            } 
        } 
    }