/**
 * @author Michael Krebs (AMVALOR)
 * @date 25.01.2017
 * @version 1
 */
#ifndef LVOX3_TRUSTINTERPOLATIONVISITOR_H
#define LVOX3_TRUSTINTERPOLATIONVISITOR_H

#include "lvox3_propagationvisitor.h"
#include "tools/lvox3_gridtype.h"
#include "lvox_sharedfortest.h"

/**
 * @brief Use this visitor to interpolate a grid with a trust (confiance) factor
 *
 * The formula used is : Sum(IDR * TF)
 *                       --------------------
 *                       Sum(TF)
 *
 * "IDR" = value of density of the cell inspected
 * "TF" a trust factor calculated like this :
 *      if ((Nt - Nb) is <= effectiveRayThreshold)                  => TF = 0
 *      if ((Nt - Nb) > endRayThreshold)                            => TF = 1
 *      if (effectiveRayThreshold < (Nb - Nt) < endRayThreshold     => TF = sin( ((Nb - Nt) - effectiveRayThreshold) / (endRayThreshold-effectiveRayThreshold))
 */
class LVOX3_TrustInterpolationVisitor : public LVOX3_PropagationVisitor
{
public:
    /**
     * @brief LVOX3_TrustInterpolationVisitor. Between effectiveRayThreshold and endRayThreshold the function will be sin((Nt-Nb)-effectiveRayThreshold)
     * @param outDensityGrid : grid to modify
     * @param inBeforeGrid : grid representing the sum of blocked rays
     * @param inTheoreticalGrid : grid representing the number of theoretical rays
     * @param effectiveRayThreshold : minimum number of effective ray (Nt-Nb must be > to threshold) to have a trust factor > 0
     * @param endRayThreshold : maximum number of effective ray. If (Nt-Nb) > endRayThreshold the trust factor will be 1
     */
    LVOX3_TrustInterpolationVisitor(const lvox::Grid3Df* inDensityGrid,
                                    lvox::Grid3Df* const outDensityGrid,
                                    const lvox::Grid3Di* inBeforeGrid,
                                    const lvox::Grid3Di* inTheoreticalsGrid,
                                    qint32 effectiveRayThreshold,
                                    qint32 endRayThreshold);

    /**
     * @brief Called when the propagation start
     * @param context : will contains all elements compute by the algorithm  when it will start. Contains
     *                  information of the first cell
     */
    void start(const LVOX3_PropagationVisitorContext& context);

    /**
     * @brief Called when a voxel must be visited
     * @param context : will contains all elements compute by the algorithm  when it will start. Contains
     *                  information of the current cell
     */
    void visit(const LVOX3_PropagationVisitorContext& context);

    /**
     * @brief Called when the propagation was finished
     * @param context : will contains all elements compute by the algorithm  when it will start. Contains
     *                  information of the first cell
     */
    void finish(const LVOX3_PropagationVisitorContext& context);

    /**
     * @brief Main trust factor computation
     * @param Nt : theoretical rays
     * @param Nb : blocked rays
     * @param effectiveRayThreshold : minimum number of rays
     * @param endRayThreshold : threshold for fully trusted value
     * @param diffEffectiveRay : endRayThreshold - effectiveRayThreshold
     */
    static double getTrustFactor(const qint32& Nt, const qint32& Nb,
                                 const qint32& effectiveRayThreshold, const qint32& endRayThreshold,
                                 const qint32& diffEffectiveRay);
private:
    const lvox::Grid3Df*    m_inGrid;
    lvox::Grid3Df* const    m_outGrid;
    const lvox::Grid3Di*    m_beforeGrid;
    const lvox::Grid3Di*    m_theoriticalsGrid;
    qint32                  m_effectiveRayThreshold;
    qint32                  m_endRayThreshold;
    qint32                  m_diffEffectiveRay;
    double                  m_denominator;
    double                  m_numerator;
};

#endif // LVOX3_TRUSTINTERPOLATIONVISITOR_H