Method scaling

dep/agg/src/agg_trans_affine.cpp:178–190

------------------------------------------------------------------------

    //------------------------------------------------------------------------
    void trans_affine::scaling(double* x, double* y) const
    {
        double x1 = 0.0;
        double y1 = 0.0;
        double x2 = 1.0;
        double y2 = 1.0;
        trans_affine t(*this);
        t *= trans_affine_rotation(-rotation());
        t.transform(&x1, &y1);
        t.transform(&x2, &y2);
        *x = x2 - x1;
        *y = y2 - y1;
    }


}