Adds two 4D vectors.
D3DXVECTOR4 * D3DXVec4Add( D3DXVECTOR4 * pOut, CONST D3DXVECTOR4 * pV1, CONST D3DXVECTOR4 * pV2 );
Pointer to a D3DXVECTOR4 structure that is the sum of the two vectors.
The return value for this function is the same value returned in the pOut parameter. In this way, the D3DXVec4Add function can be used as a parameter for another function.
Header: Declared in D3dx9math.h.