BSIQuadrature.h

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/*--------------------------------------------------------------------------------------+
|
|   Supplied under applicable software license agreement.
|
|   Copyright (c) 2018 Bentley Systems, Incorporated. All rights reserved.
|
+---------------------------------------------------------------------------------------*/
#pragma once

BEGIN_BENTLEY_GEOMETRY_NAMESPACE
//#include <Geom/msgeomstructs_typedefs.h>

#ifdef __cplusplus

class GEOMDLLIMPEXP BSIVectorIntegrand
{
public:
GEOMAPI_VIRTUAL ~BSIVectorIntegrand(){}
GEOMAPI_VIRTUAL void EvaluateVectorIntegrand (double t, double *pF) = 0;
GEOMAPI_VIRTUAL int  GetVectorIntegrandCount () = 0;
};

class GEOMDLLIMPEXP BSIIncrementalVectorIntegrand : public BSIVectorIntegrand
{
public:
GEOMAPI_VIRTUAL ~BSIIncrementalVectorIntegrand(){}
// Return true to continue integration.
GEOMAPI_VIRTUAL bool AnnounceIntermediateIntegral (double t, double *pIntegrals) = 0;
};


class BSIVectorIntegrandXY
{
public:
GEOMAPI_VIRTUAL void EvaluateVectorIntegrand (double x, double y, double *pF) = 0;
GEOMAPI_VIRTUAL int GetVectorIntegrandCount () = 0;
};


struct GEOMDLLIMPEXP BSIQuadraturePoints
{
private:
    static int const MaxPoints = 20;
    double mWi[MaxPoints];
    double mUi[MaxPoints];
    int    mNumEval;

    double mU0, mU1;    // Limits of idealized interval.
    double mDivDU;      // Precomputed 1/ (mU1 - mU0);
    double mConvergencePower;    // Expected degree of convergence.

    bool AddEval (double u, double w);
    void Init(double u0, double u1);
public:

int InitUniform (int numEval);

int InitGauss (int numEval);

int InitGaussLobatto (int numEval);

int InitGaussKronrod (int numEval, BSIQuadraturePoints &gaussPartner);

bool GetEval (int i, double a0, double a1, double &a, double &w) const;

static bool GetXYEval (
    BSIQuadraturePoints const &xRule, int ix, double x0, double x1,
    BSIQuadraturePoints const &yRule, int iy, double y0, double y1,
    double &x, double &y, double &w
    );
    


int GetNumEval () const;

double GetConvergencePower () const;

void AccumulateWeightedSums
(
BSIVectorIntegrand &function,
double t0,
double t1,
double *pSums,
int     numInterval
);

/*----------------------------------------------------------------*/
bool IntegrateWithRombergExtrapolation
(
BSIIncrementalVectorIntegrand &function,
double t0,
double t1,
uint32_t numInterval,
double &totalErrorBound
);
BSIQuadraturePoints ();
};



struct GEOMDLLIMPEXP BSITriangleQuadraturePoints
{
private:
    static int const MaxPoints = 20;
    double mWi[MaxPoints];
    double mUi[MaxPoints];
    double mVi[MaxPoints];
    int    mNumEval;

    double mConvergencePower;    // Expected degree of convergence.

    bool AddEval (double u, double v, double w);
    void Init();
public:


int InitStrang (int selector);

bool GetEval (int i, double &u, double &v, double &w) const;    

int GetNumEval () const;

double GetConvergencePower () const;

BSITriangleQuadraturePoints ();

void AccumulateWeightedSums(BSIVectorIntegrandXY &function, double *pSums);

void AccumulateWeightedSumsMapped
    (
    BSIVectorIntegrandXY &function, double *pSums, 
    double ax, double ay,
    double bx, double by,
    double cx, double cy
    );

};



#endif
END_BENTLEY_GEOMETRY_NAMESPACE