Simple camera class in FTS - lookAt function. (See related posts)

/// Makes the camera look at a certain point.
/** This function makes the camera look at a certain point. If that point is the same as its
 *  current position, the camera moves back the (current) distance |camera-target|.
 *
 * \param in_vTgt The position where the camera should look at.
 *
 * \return If successfull: ERR_OK
 * \return If failed:      An error code < 0
 *
 * \author Pompei2
 */
CFTSCamera *CFTSCamera::lookAt(const CFTSVector & in_vTgt)
{
    // Calculate the new front vector that points to the target.
    CFTSVector vNewFront = (in_vTgt - m_vPos).normalize();

    // The two vectors are in one plane. This gives us the cosine of the angle between
    // these two vectors.
    float fDotProd = vNewFront.dot(m_vFront);
    if(fDotProd > 1.0f || fDotProd < -1.0f)
        return this;

    // By getting the arc cosine of this, we get the angle in radians between the two
    // vectors. But we only get an angle between 0 and pi, that will be a problem.
    float fAlpha = acosf(fDotProd);

    // Here we get the normal to these two vectors, we will need to rotate our front
    // vector around this normal.
    CFTSVector vNormal = vNewFront.cross(m_vFront).normalize();

    // As I said, we have a problem: as we only get an angle between 0 and pi,
    // we don't know if we need to rotate clockwise or counterclockwise ...
    // We solve this problem by just trying it out.
    CFTSVector vFrontTest = m_vFront.rotate(vNormal, fAlpha);

    // If the dot product is near to one, it means we were right. with our guess
    // rotating counterclockwise.
    // Else, we must rotate clockwise.
    fDotProd = vFrontTest.dot(vNewFront);
    if(fabs(fDotProd) > (1.0f - D_FTS_DELTA)) {
            m_vFront = vFrontTest;
            m_vUp = m_vUp.rotate(vNormal, fAlpha);
            m_vRight = m_vRight.rotate(vNormal, fAlpha);
    } else {
            m_vFront = m_vFront.rotate(vNormal, -fAlpha);
            m_vUp = m_vUp.rotate(vNormal, -fAlpha);
            m_vRight = m_vRight.rotate(vNormal, -fAlpha);
    }

    // If the dot product is near to -1, it means we look the wrong way.
    // To correct this, we just rotate pi radians (a half circle).
    if(fDotProd < -(1.0f - D_FTS_DELTA))
        this->rotateYRadians(M_PI);

    return this;
}