STDMETHODIMP CVectorObject::Rotate(float fTheta, IVector *pvres)
{
D3DVECTOR rlvThis, rlvRotated, rlvAxis;
D3DVALUE valModulus;
if (!pvres)
return E_POINTER;
rlvThis.x = m_x;
rlvThis.y = m_y;
rlvThis.z = m_z;
rlvAxis.x = 0.0F;
rlvAxis.y = 1.0F;
rlvAxis.z = 0.0F;
valModulus = D3DRMVectorModulus(&rlvThis);
D3DRMVectorRotate(&rlvRotated, &rlvThis, &rlvAxis, fTheta);
// D3DRMVectorRotate will return a unit vector. We need the original size vector.
D3DRMVectorScale(&rlvRotated, &rlvRotated, valModulus);
pvres->set(rlvRotated.x, rlvRotated.y, rlvRotated.z);
return S_OK;
}
STDMETHODIMP CVectorObject::RotateAboutAxis(float fTheta, float fAxisX, float fAxisY, float fAxisZ)
{
D3DVECTOR rlvThis, rlvRotated, rlvAxis;
D3DVALUE valModulus;
HRESULT hr = S_OK;
if (fAxisX == 0.0f && fAxisY == 0.0f && fAxisZ == 0.0f)
return E_INVALIDARG;
rlvThis.x = m_x;
rlvThis.y = m_y;
rlvThis.z = m_z;
rlvAxis.x = fAxisX;
rlvAxis.y = fAxisY;
rlvAxis.z = fAxisZ;
valModulus = D3DRMVectorModulus(&rlvThis);
D3DRMVectorRotate(&rlvRotated, &rlvThis, &rlvAxis, fTheta);
// D3DRMVectorRotate will return a unit vector. We need the original size vector.
D3DRMVectorScale(&rlvRotated, &rlvRotated, valModulus);
hr = set(rlvRotated.x, rlvRotated.y, rlvRotated.z);
return hr;
}
/* Normalize a vector. Returns (1,0,0) if INPUT is the NULL vector. */
LPD3DVECTOR WINAPI D3DRMVectorNormalize(LPD3DVECTOR u)
{
D3DVALUE modulus = D3DRMVectorModulus(u);
if(modulus)
{
D3DRMVectorScale(u,u,1.0/modulus);
}
else
{
u->u1.x=1.0;
u->u2.y=0.0;
u->u3.z=0.0;
}
return u;
}
