use Inline C => Config => CCFLAGS => '' => LIBS => '' => CC => 'gcc';
#use Inline C => Config => CCFLAGS => '' => LIBS => '' => CC => 'cl';
#use Inline C;

1;

__DATA__
__C__
#include <stdio.h>
#include <math.h>
#include <float.h>

double TaucLorentz(double E, double e1inf, double e2inf, 
				   double A, double Eg, double En0, double C)
{

	double pi = 3.1415926535;
	double e1TL, e2TL, e2Tauc, L;
	double EminusEg, EplusEg, aln, atan, gsi4, lnE, lnEngrt;
	double dEEg;

	double Eg2    = Eg * Eg;
	double En02   = En0* En0;
	double C2     = C * C;
	double alpha  = sqrt(4.0 * En02 - C2);
	double gamma  = sqrt(En02 - C2/2.0);
	double alpha2 = alpha * alpha;
	double gamma2 = gamma * gamma;

	double lnEn0g   = log( (En02+Eg2+alpha*Eg) / (En02+Eg2-alpha*Eg) );
	double atanEgaC = pi - atan2( (2.0*Eg+alpha)/C, 1.0 ) + atan2( (-2.0*Eg+alpha)/C, 1.0 );
	double atangEg  = pi + 2.0*atan2( 2.0 * (gamma2-Eg2) / alpha / C, 1.0 );

	double E2     = E * E;

	e2TL = e2inf;
	if(E > Eg) {
		dEEg = E - Eg;
		e2Tauc = A * dEEg * dEEg / E / E;
		L = En0 * C * E / ( (E2-En02)*(E2-En02) + C2*E2 );
		e2TL = e2inf + e2Tauc * L;
	}

/* E == Egの場合、log(|E-Eg|)の2つの項が打ち消しあうので、|E-Eg|を1と置き換えても結果は変わらない */
	EminusEg = 1.0;
	if(E != Eg) {
		EminusEg = fabs(E - Eg);
	}
	EplusEg  = E + Eg;
	aln      = (Eg2-En02) * E2 + Eg2*C2 - En02 * (En02 + 3.0*Eg2);
	atan     = (E2-En02) * (En02+Eg2) + Eg2*C2;
	gsi4     = (E2-gamma2)*(E2-gamma2) + alpha2*C2/4.0;
	lnE      = log( EminusEg / EplusEg );
	lnEngrt  = log( EminusEg * EplusEg / sqrt( (En02-Eg2)*(En02-Eg2) + Eg2*C2 ) );

	e1TL = e1inf
			+ (A*C/pi/gsi4) * (aln/2.0/alpha/En0) * lnEn0g
			- (A/pi/gsi4) * (atan/En0) * atanEgaC
			+ 2.0 * (A*En0/pi/gsi4/alpha) * Eg * (E2-gamma2) * atangEg
			- (A*En0*C/pi/gsi4) * (E2+Eg2)/E * lnE
			+ (2.0*A*En0*C/pi/gsi4) * Eg * lnEngrt;
/*
	*pe1 = e1TL;
	*pe2 = e2TL;
*/
	return e1TL;
}