#ifndef EIM_H
#define EIM_H

/*
 * METRIC --- Mode expansion modeling in integrated optics / photonics
 * http://metric.computational-photonics.eu/ 
 */

/*
 * eim.h
 * Procedures related to an effective-index-like dimensionality reduction   
 * 2D -> 1D for integrated optical scattering problems
 */

/* ------------------------------------------------------------------------ */ 

/* field container, including the solver procedure */

class EimField
{
public:
	// the structure in question
	SegWgStruct str;

	// polarization: TE, TM
	Polarization pol;

	// vacuum wavelength and derived quantities
	double lambda;
	double k0;
	double invommu0;
	double invomep0;

	// initialize; 
	EimField(SegWgStruct s, Polarization p, double wl);

	// the vEIM solver
	// v = 0: standard version, 
	// v = 1: modified 'vectorial' approach
	void solve(int v);
	void solve() { solve(0); }

	// the resulting field 
	Complex field(Fcomp cp, double x, double z) const;
	// values on a rectangular mesh
	Cmatrix field(Fcomp cp, Interval wx, int npx, 
	                        Interval wz, int npz) const;

	// ----------------------------------------------------------- 
	// internal representation of the principal field component, 
	// adjusted / calculated by the solver

	// vertical mode shape
	Mode vp;
	// effective permittivity profile
	Waveguide epseff;
	Waveguide epseff_b;
	// horizontal field shape 
	ModeArray hp;
	Cvector amp;
	// reflection, transmission
	double ref;
	double trans;

	// ----------------------------------------------------------- 
	// preparation of physical field plots:
        // selection of the global phase / snapshot time 0 within one period

        // multiply the entire field by a phase factor exp(i phi),
        // the internal representation is modified accordingly
        void adjustphase(double phi);

        // adjust the global phase, such that a plot(cp, ORG) of the physical
        // basic field component (cp = EY for TE, cp = HY for TM) exhibits the
        // maximum field at position (x, z)
        void adjustphase(double x, double z);

	// adjust the global phase, such that a plot(cp, ORG) of the physical
	// basic field component (cp = EY for TE, cp = HY for TM) exhibits an
	// overall field maximum (-> time snapshot of an extremal state
	// in case of a configuration with partially standing waves)
	// ... determine the maximum on a regular mesh of numx * mumz points
	//     on the window given by xbeg, xend, zbeg, zend 
	void adjustphase(double xbeg, double xend, double zbeg, double zend,
	                 int numx, int numz);

	// ----------------------------------------------------------- 
	// visualization: output to MATLAB .m files  
	// evaluation of the mode interference pattern in the display window 
	// xbeg <= x <= xend, zbeg <= z <=zend 
	// npx, npz: number of points in output mesh
	// ext0, ext1: filename id characters for the .m file

	// image plot corresponding to field component cp
	// cp: EX, EY, EZ, HX, HY, HZ, SX, SY, SZ 
	// foa: MOD, SQR, REP, IMP
	void plot(Fcomp cp, Afo foa,
                  double xbeg, double xend, double zbeg, double zend, 
	          int npx, int npz, char ext0, char ext1) const;

	// export full field data ("everything") into a viewer MATLAB file
        void viewer(double xbeg, double xend, double zbeg, double zend,
                    int npx, int npz, char ext0, char ext1) const;

private:

};

#endif // EIM_H