include <d3dx9.h>
  include <iostream>
  using namespace std;
  
  // Overload the  "<<" operators so that we can use cout to 
  // output D3DXVECTOR3 objects.
  
  ostream& operator<<(ostream& os, D3DXVECTOR3& v)
  {
          os << "(" << v.x << ", " << v.y << ", " << v.z << ")";
          return os;
  }
  
  int main()
  {
          // Using constructor, D3DXVECTOR3(FLOAT x, FLOAT y, FLOAT z);
          D3DXVECTOR3 u(1.0f, 2.0f, 3.0f);
  
          // Using constructor, D3DXVECTOR3(CONST FLOAT *);
          float x[3] = {-2.0f, 1.0f, -3.0f};
          D3DXVECTOR3 v(x);
  
          // Using constructor, D3DXVECTOR3() {};
          D3DXVECTOR3 a, b, c, d, e;  
  
          // Vector addition: D3DXVECTOR3 operator + 
          a = u + v;
  
          // Vector subtraction: D3DXVECTOR3 operator - 
          b = u - v;
  
          // Scalar multiplication: D3DXVECTOR3 operator * 
          c = u * 10;
  
          // ||u||
          float length = D3DXVec3Length(&u);
  
          // d = u / ||u||
          D3DXVec3Normalize(&d, &u);
  
          // s = u dot v
          float s = D3DXVec3Dot(&u, &v);
  
          // e = u x v
          D3DXVec3Cross(&e, &u, &v);
  
          cout << "u       = " << u << endl;
          cout << "v       = " << v << endl;
          cout << "a       = " << a << endl;
          cout << "b       = " << b << endl;
          cout << "c       = " << c << endl;
          cout << "d       = " << d << endl;
          cout << "e       = " << e << endl;
          cout << "||u||   = " << length << endl;
          cout << "u dot v = " << s << endl;
  
          return 0;
  }