Function invTransformCubicBzeirs

plugin/seq/plotPDF.cpp:1981–2019

            zx.push_back( x );
	    zy.push_back( y );
        }
    }
    return;
}

void invTransformCubicBzeirs( std::vector< std::vector<double> > &Cxs, std::vector< std::vector<double> > &Cys,
			      const double *const PHI )
{
    const double EPS = 1e-10;

    const double &lambda1 = PHI[0]; const double &lambda2 = PHI[1];
    const double &D = PHI[6]; const double &E = PHI[7];

    const double &ev1x = PHI[2]; const double &ev1y = PHI[3];
    const double &ev2x = PHI[4]; const double &ev2y = PHI[5];
    const double  P[2][2] = { { ev1x, ev2x }, { ev1y, ev2y } };

    assert( Cxs.size() == Cys.size() );

    if( Cxs.size() == 0 ) return; // nothing to transform

    for(size_t k = 0; k < Cxs.size(); k++){

	std::vector<double> &Cx = Cxs[k];
	std::vector<double> &Cy = Cys[k];

	assert( Cx.size() == Cy.size() );

	for(size_t j = 0; j < Cx.size(); j++){ // j=0 : starting point

	    double Px = Cx[j];
	    double Py = Cy[j];

	    if( fabs(lambda1) > EPS )
		Px -= D/(2*lambda1);
	    if( fabs(lambda2) > EPS )
		Py -= E/(2*lambda2);

	    Cx[j] = P[0][0] * Px + P[0][1] * Py;
	    Cy[j] = P[1][0] * Px + P[1][1] * Py;
	}
    } // k