private static void OnMouse(int button, int state, int x, int y)
        {
            // this method gets called whenever a new mouse button event happens
            if(button == Glut.GLUT_RIGHT_BUTTON) mouseDown = (state == Glut.GLUT_DOWN);

            // if the mouse has just been clicked then we hide the cursor and store the position
            if(mouseDown)
            {
                Glut.glutSetCursor(Glut.GLUT_CURSOR_NONE);
                downX = x;
                downY = y;
                ty = 0;
                tp = 0;
            }
            else // unhide the cursor if the mouse has just been released
            { Glut.glutSetCursor(Glut.GLUT_CURSOR_LEFT_ARROW); }
        }
        public static float ty = 0,tp = 0;
        private static void OnMove(int x, int y)
        {
            // if the mouse move event is caused by glutWarpPointer then do nothing
            //if((x == downX && y == downY) || Math.Pow((downX - x), 2) + Math.Pow((downY - y), 2) < 16) return;
            if(x == downX && y == downY)return;
            // move the camera when the mouse is down
            if(mouseDown)
            {
                float yaw = (downX - x) * 0.002f;
                ty += yaw;
                camera.Yaw(yaw);

                float pitch = (downY - y) * 0.002f;
                tp += pitch;
                camera.Pitch(pitch);

                Glut.glutWarpPointer(downX, downY);
                Console.Clear();
                Console.WriteLine(ty.ToString() + "   " + tp.ToString() + "   " + downX.ToString() + "   " + downY.ToString() + "   " + x.ToString() + "   " + y.ToString());
            }
        }