function math.angle(x1,y1, x2,y2)
     return math.atan2(x2-x1, y2-y1)
end

using System;  
using WindmillEngine;  

namespace FirstGame  
{  
       class Program  
       {  
           static void Main()  
           {  
               Windmill ge = new Windmill();  
               ge.IniEngine("FirstGame", 800, 600, false, ge.COLOR(255, 0, 0, 0));  
               ge.RunEngine(null);  
           }  

           static void Game(Windmill gameEngine)  
           {  
               gameEngine.DrawLine(10, 10, 400, 400, 1, 1, gameEngine.COLOR(255, 255, 255, 255));  
           }  
       }  
}