#////////////////////////////////////////////////////////
//  Small linear mesh to substitute the array from PData
//  The mesh is inherited from TF1, and allow to use
//  mesh->Draw()
//  
//
//                    Author: I. Froehlich
//                    Written: 7.05.2007
//                    Revised: 
//
////////////////////////////////////////////////////////


#include "PMesh.h"
#include <iostream>
#include "TH1.h"
#include "TROOT.h"
#include "TVirtualPad.h"

using namespace std;

PMesh::PMesh(Int_t psize, const Char_t * name):TF1(name,"0", 0, 1) {
    // Copied from TF1 constructor... 
    SetName(name);
    fNpar = 0;

    fXmin      = 0.;
    fXmax      = 0.;

    fNpx       = psize-1;

#if ( ROOT_VERSION_CODE >= ROOT_VERSION(6,12,0) )
    fType      = static_cast<TF1::EFType>(0);
#else
    fType = 0;
#endif

    //    fFunction  = 0;
    fNdim = 1;
    
    if (psize<=0) {
	cout << "PMesh::PMesh: size " << psize << " not allowed" << endl;
	td=nullptr;
    }
    td=new Double_t[psize];
    size=psize;
    max=0.;
    min=0.;
}

PMesh::~PMesh() {
    if (td) delete[] td;
};

Double_t PMesh::EvalPar(const Double_t *x, const Double_t* /*params*/) {
    return Eval(x[0]);
}
 
Double_t PMesh::Eval(Double_t x, Double_t /*y*/ , Double_t /*z*/ , Double_t /*t*/ ) const
{
    return GetLinearIP(x);
}

void     PMesh::SetNode(Int_t node,Double_t v) {
    if ((node>=size) || (node<0))
	return;
    td[node]=v;
};

Double_t PMesh::GetNode(Int_t node){
    if ((node>=size) || (node<0))
	return 0;
    return td[node];
};

void PMesh::Print(const Option_t* /*delme*/) const {
    cout << "Min:  " << min << endl;
    cout << "Max:  " << max << endl;
    cout << "Size: " << size << endl;
    TF1::Print();
}

Double_t PMesh::GetLinearIP(Double_t m) const {
    if ((m > min)  && (m < max) ) {
	Double_t dm=(max-min)/(size-1.); 
	
	int bin     = int((m-min)/dm);
	
	double mlow = min + bin*dm,
	    mup  = mlow + dm,
	    wlow = td[bin],
	    wup  = td[bin+1];
	return ((mup*wlow-mlow*wup) + m*(wup-wlow))/dm;
    }
    //catch NAN
    return 0;     // mass out of bounds

};