float SquaredDistancePointSolidBox (Box box, Point P)
{
    D = P - box.C;
    sqrDist = 0;
    isInsideBox = true;

    for (i = 0; i < 3; i++)
    {
        s[i] = Dot(box.U[i],D);
        if ( s[i] <= -box.e[i] )
        {
            isInsideBox = false;
            delta = s[i] + box.e[i];
            sqrDist += delta*delta;
        }
        else if ( s[i] >= box.e[i] )
        {
            isInsideBox = false;
            delta = s[i] - box.e[i];
            sqrDist += delta*delta;
        }
    }

    if ( isInsideBox )
    {
        dist = min(box.e[0]-|s[0]|,box.e[1]-|s[1]|,box.e[2]-|s[2]|);
        sqrDist = dist*dist;
    }

    return sqrDist;
}