The definition of the internal DirectX D3DMATRIX object is as follows:

struct D3DMATRIX {
D3DVALUE _11;
D3DVALUE _12;
D3DVALUE _13;
D3DVALUE _14;
D3DVALUE _21;
D3DVALUE _22;
D3DVALUE _23;
D3DVALUE _24;
D3DVALUE _31;
D3DVALUE _32;
D3DVALUE _33;
D3DVALUE _34;
D3DVALUE _41;
D3DVALUE _42;
D3DVALUE _43;
D3DVALUE _44;
};