Node rotation via quaternions

//-----------------------------------------------------------------------
void Node::rotate(const quaternion &quat, const TransformSpace::TransformSpace &space)
{
    // Skip if no rotation
    if(quat == quaternion::IDENTITY) return;

        // Apply in correct space
    switch(space)
    {
        // Frist rotate, then apply current
        case TransformSpace::LOCAL :
                _orientation *= quat;
                break;

            // First apply current, then rotate
            case TransformSpace::PARENT :
                _orientation = quat * _orientation;
                break;
    }

    // Normalize quaternion
    _orientation = _orientation.normalize();

    // Set update flag
    _update = true;
}