// This member function multiplies this vqs with the given vector3 vec. As
// shown in notes.
CVector3 vqs::MultiplyVector( const CVector3& vec ) const
{
//Turn the vector into a quaternion-vector.
DQuaternion quatVec(vec);
//Get the inverse of the current quaternion.
DQuaternion inverse = this->orientation();
inverse.inverted();
//Now multiply inverse*quatVec, then quatVec*normal
quatVec = inverse * quatVec;
quatVec = quatVec * this->orientation();
//Easily transforms back into a vector.
CVector3 result(quatVec.x, quatVec.y, quatVec.z);
//Apply translation to vector.
result = result + this->translation();
//Apply scale after translation.
result = result * this->scale();
//operation is complete.
return result;
}
void rQuaternion::TransformVector3(rVector3& v) const{
rVector3 quatVec(x, y , z);
rVector3 uv = quatVec.Cross(v);
rVector3 uuv = quatVec.Cross(uv);
uv *= (2.0f * w);
uuv *= 2.0f;
v= v + uv + uuv;
}
Vec3f operator*(const Quaternion &quat, const Vec3f &vec)
{
Vec3f quatVec(quat.x, quat.y, quat.z);
Vec3f uv(quatVec.Cross(vec));
Vec3f uuv(quatVec.Cross(uv));
uv *= 2.0f * quat.w;
uuv *= 2.0f;
return vec + uv + uuv;
}
