| DirectX SDK | 
The D3DXVECTOR4 structure describes a vector in four-dimensional (4-D) space.
typedef struct D3DXVECTOR4 {
  float x, y, z, w;
} D3DXVECTOR4;
C++ programmers can take advantage of operator overloading and type casting. The C++ implementation of the D3DXVECTOR4 structure implements overloaded constructors and overloaded assignment, unary and binary (including equality) operators. For more information, see C++ Specific Features.
  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Windows CE: Unsupported.
  Version: Requires DirectX 7.0.
  Header: Declared in d3dxmath.h.
D3DXVec4Length, D3DXVec4LengthSq, D3DXVec4Dot, D3DXVec4Add, D3DXVec4Subtract, D3DXVec4Minimize, D3DXVec4Maximize, D3DXVec4Scale, D3DXVec4Lerp, D3DXVec4Cross, D3DXVec4Normalize, D3DXVec4Hermite, D3DXVec4BaryCentric, D3DXVec4Transform