/**
	This software was developed by the University of Tennessee as part of the
	Distributed Data Analysis of Neutron Scattering Experiments (DANSE)
	project funded by the US National Science Foundation.

	If you use DANSE applications to do scientific research that leads to
	publication, we ask that you acknowledge the use of the software with the
	following sentence:

	"This work benefited from DANSE software developed under NSF award DMR-0520547."

	copyright 2009, University of Tennessee
 */
#ifndef SMEARER_CLASS_H
#define SMEARER_CLASS_H

#include <vector>

using namespace std;

/**
 * Base smearer class, implementing the matrix multiplication only
 */
class BaseSmearer {
protected:
	// Internal flag: true when the weights vector is filled
	bool has_matrix;
	// True when only qmin, qmax and nbins are given. Bins are equidistant
	bool even_binning;
	// Smearing matrix
	vector<double>* weights;
	// Q vector
	double* q_values;
    // Q_min (Min Q-value for I(q))
    double qmin;
    // Q_max (Max Q_value for I(q))
    double qmax;
    // Number of Q bins
    int nbins;

public:
    // Constructor
    BaseSmearer(double qmin, double qmax, int nbins);
    BaseSmearer(double* q, int nbins);
	// Smear function
	virtual void smear(double *, double *, int, int);
	// Compute the smearing matrix
	virtual void compute_matrix(){};
	// Utility function to check the number of bins
	int get_nbins() { return nbins; }
	// Get the q range of a particular bin
	virtual int get_bin_range(int, double*, double*, double*);
};


/**
 * Slit smearer class
 */
class SlitSmearer : public BaseSmearer {

protected:
    // Number of points used in the smearing computation
    static const int npts   = 500;

public:
    // Slit width in Q units
    double width;
    // Slit height in Q units
    double height;

    // Constructor
	SlitSmearer(double width, double height, double qmin, double qmax, int nbins);
	SlitSmearer(double width, double height, double* q, int nbins);
	// Compute the smearing matrix
	virtual void compute_matrix();
};


/**
 * Point smearer class
 */
class QSmearer : public BaseSmearer {

protected:
    // Standard deviation in Q [A-1]
    double* width;

public:

    // Constructor
    QSmearer(double* width, double qmin, double qmax, int nbins);
    QSmearer(double* width, double* q, int nbins);
	// Compute the smearing matrix
	virtual void compute_matrix();
};

#endif