path: root/geom_bottleneck/include/basic_defs_bt.h

/*

Copyright (c) 2015, M. Kerber, D. Morozov, A. Nigmetov
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

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You are under no obligation whatsoever to provide any bug fixes, patches, or
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*/

#ifndef HERA_BASIC_DEFS_BT_H
#define HERA_BASIC_DEFS_BT_H

#ifdef _WIN32
#include <ciso646>
#endif

#include <vector>
#include <stdexcept>
#include <math.h>
#include <cstddef>
#include <unordered_map>
#include <unordered_set>
#include <string>
#include <assert.h>

#include "def_debug_bt.h"

#ifndef FOR_R_TDA
#include <iostream>
#endif

namespace  hera {
namespace bt {

typedef int IdType;
constexpr IdType MinValidId = 10;

template<class Real = double>
struct Point {
    Real x, y;

    bool operator==(const Point<Real> &other) const
    {
        return ((this->x == other.x) and (this->y == other.y));
    }

    bool operator!=(const Point<Real> &other) const
    {
        return !(*this == other);
    }

    Point(Real ax, Real ay) : x(ax), y(ay) {}

    Point() : x(0.0), y(0.0) {}

#ifndef FOR_R_TDA

    template<class R>
    friend std::ostream& operator<<(std::ostream& output, const Point<R>& p)
    {
        output << "(" << p.x << ", " << p.y << ")";
        return output;
    }

#endif
};

template<class Real = double>
struct DiagramPoint {
    // Points above the diagonal have type NORMAL
    // Projections onto the diagonal have type DIAG
    // for DIAG points only x-coordinate is relevant
    // to-do: add getters/setters, checks in constructors, etc
    enum Type {
        NORMAL, DIAG
    };
    // data members
private:
    Real x, y;
public:
    Type type;
    IdType id;

    // operators, constructors
    bool operator==(const DiagramPoint<Real> &other) const
    {
        // compare by id only
        assert(this->id >= MinValidId);
        assert(other.id >= MinValidId);
        bool areEqual{ this->id == other.id };
        assert(!areEqual or  ((this->x == other.x) and (this->y == other.y) and (this->type == other.type)));
        return areEqual;
    }

    bool operator!=(const DiagramPoint &other) const
    {
        return !(*this == other);
    }

    DiagramPoint(Real _x, Real _y, Type _type, IdType _id) :
        x(_x),
        y(_y),
        type(_type),
        id(_id)
    {
        if ( _y == _x and _type != DIAG)
            throw std::runtime_error("Point on the main diagonal must have DIAG type");

    }


    bool isDiagonal(void) const { return type == DIAG; }

    bool isNormal(void) const { return type == NORMAL; }

    Real inline getRealX() const // return the x-coord
    {
        return x;
    }

    Real inline getRealY() const // return the y-coord
    {
        return y;
    }

#ifndef FOR_R_TDA
    template<class R>
    friend std::ostream& operator<<(std::ostream& output, const DiagramPoint<R>& p)
    {
        if ( p.isDiagonal() ) {
            output << "(" << p.x << ", " << p.y << ", " <<  0.5 * (p.x + p.y) << ", "  << p.id << " DIAG )";
        } else {
            output << "(" << p.x << ", " << p.y << ", " << p.id << " NORMAL)";
        }
        return output;
    }
#endif

};

// compute l-inf distance between two diagram points
template<class Real>
Real distLInf(const DiagramPoint<Real>& a, const DiagramPoint<Real>& b)
{
    if ( a.isDiagonal() and b.isDiagonal() ) {
        // distance between points on the diagonal is 0
        return 0.0;
    }
    // otherwise distance is a usual l-inf distance
    return std::max(fabs(a.getRealX() - b.getRealX()), fabs(a.getRealY() - b.getRealY()));
}


template <class T>
inline void hash_combine(std::size_t & seed, const T & v)
{
    std::hash<T> hasher;
    seed ^= hasher(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
}

//template<class Real = double>
//struct PointHash {
//    size_t operator()(const Point<Real> &p) const
//    {
//        size_t seed = 0;
//        hash_combine(seed, p.x);
//        hash_combine(seed, p.y);
//        return seed;
//    }
//};

template<class Real = double>
struct DiagramPointHash {
    size_t operator()(const DiagramPoint<Real> &p) const
    {
        assert(p.id >= MinValidId);
        return std::hash<int>()(p.id);
    }
};

template<class Real = double>
Real distLInf(const DiagramPoint<Real> &a, const DiagramPoint<Real> &b);

//template<class Real = double>
//typedef std::unordered_set<Point, PointHash> PointSet;
template<class Real_ = double>
class DiagramPointSet;

template<class Real>
void addProjections(DiagramPointSet<Real> &A, DiagramPointSet<Real> &B);

template<class Real_>
class DiagramPointSet {
public:

    using Real = Real_;
    using DgmPoint = DiagramPoint<Real>;
    using DgmPointHash = DiagramPointHash<Real>;
    using const_iterator = typename std::unordered_set<DgmPoint, DgmPointHash>::const_iterator;
    using iterator = typename std::unordered_set<DgmPoint, DgmPointHash>::iterator;

private:

    bool isLinked { false };
    IdType maxId { MinValidId + 1 };
    std::unordered_set<DgmPoint, DgmPointHash> points;

public:

    void insert(const DgmPoint& p)
    {
        points.insert(p);
        if (p.id > maxId) {
            maxId = p.id + 1;
        }
    }

    void erase(const DgmPoint& p, bool doCheck = true)
    {
    // if doCheck, erasing non-existing elements causes assert
        auto it = points.find(p);
        if (it != points.end()) {
            points.erase(it);
        } else {
            assert(!doCheck);
        }
    }


    void erase(const const_iterator it)
    {
        points.erase(it);
    }

    void removeDiagonalPoints()
    {
        if (isLinked) {
            auto ptIter = points.begin();
            while(ptIter != points.end()) {
                if (ptIter->isDiagonal()) {
                    ptIter = points.erase(ptIter);
                } else {
                    ptIter++;
                }
            }
            isLinked = false;
        }
    }

    size_t size() const
    {
        return points.size();
    }

    void reserve(const size_t newSize)
    {
        points.reserve(newSize);
    }

    void clear()
    {
        points.clear();
    }

    bool empty() const
    {
        return points.empty();
    }

    bool hasElement(const DgmPoint &p) const
    {
        return points.find(p) != points.end();
    }

    iterator find(const DgmPoint &p)
    {
        return points.find(p);
    }

    iterator begin()
    {
        return points.begin();
    }

    iterator end()
    {
        return points.end();
    }

    const_iterator find(const DgmPoint &p) const
    {
        return points.find(p);
    }

    const_iterator cbegin() const
    {
        return points.cbegin();
    }

    const_iterator cend() const
    {
        return points.cend();
    }

#ifndef FOR_R_TDA
    template<class R>
    friend std::ostream& operator<<(std::ostream& output, const DiagramPointSet<R>& ps)
    {
        output << "{ ";
        for(auto pit = ps.cbegin(); pit != ps.cend(); ++pit) {
            output << *pit << ", ";
        }
        output << "\b\b }";
        return output;
    }
#endif

    friend void addProjections<Real_>(DiagramPointSet<Real_>& A, DiagramPointSet<Real_>& B);

    template<class PairIterator>
    void fillIn(PairIterator begin_iter, PairIterator end_iter)
    {
        isLinked = false;
        clear();
        IdType uniqueId = MinValidId + 1;
        for (auto iter = begin_iter; iter != end_iter; ++iter) {
            insert(DgmPoint(iter->first, iter->second, DgmPoint::NORMAL, uniqueId++));
        }
    }

    template<class PointContainer>
    void fillIn(const PointContainer& dgm_cont)
    {
        using Traits = DiagramTraits<PointContainer>;
        isLinked = false;
        clear();
        IdType uniqueId = MinValidId + 1;
        for (const auto& pt : dgm_cont) {
            Real x = Traits::get_x(pt);
            Real y = Traits::get_y(pt);
            insert(DgmPoint(x, y, DgmPoint::NORMAL, uniqueId++));
        }
    }


    // ctor from range
    template<class PairIterator>
    DiagramPointSet(PairIterator begin_iter, PairIterator end_iter)
    {
        fillIn(begin_iter, end_iter);
    }

    // ctor from container, uses DiagramTraits
    template<class PointContainer>
    DiagramPointSet(const PointContainer& dgm)
    {
        fillIn(dgm);
    }


    // default ctor, empty diagram
    DiagramPointSet(IdType minId = MinValidId + 1) : maxId(minId + 1) {};

    IdType nextId() { return maxId + 1; }

}; // DiagramPointSet


template<class Real, class DiagPointContainer>
Real getFurthestDistance3Approx(DiagPointContainer& A, DiagPointContainer& B) {
    Real result{0.0};
    DiagramPoint<Real> begA = *(A.begin());
    DiagramPoint<Real> optB = *(B.begin());
    for (const auto &pointB : B) {
        if (distLInf(begA, pointB) > result) {
            result = distLInf(begA, pointB);
            optB = pointB;
        }
    }
    for (const auto &pointA : A) {
        if (distLInf(pointA, optB) > result) {
            result = distLInf(pointA, optB);
        }
    }
    return result;
}

// preprocess diagrams A and B by adding projections onto diagonal of points of
// A to B and vice versa. NB: ids of points will be changed!
template<class Real_>
void addProjections(DiagramPointSet<Real_>& A, DiagramPointSet<Real_>& B)
{

    using Real = Real_;
    using DgmPoint = DiagramPoint<Real>;
    using DgmPointSet = DiagramPointSet<Real>;

    IdType uniqueId {MinValidId + 1};
    DgmPointSet newA, newB;

    // copy normal points from A to newA
    // add projections to newB
    for(auto& pA : A) {
        if (pA.isNormal()) {
            DgmPoint dpA {pA.getRealX(), pA.getRealY(), DgmPoint::NORMAL, uniqueId++};
            DgmPoint dpB {(pA.getRealX() +pA.getRealY())/2, (pA.getRealX() +pA.getRealY())/2, DgmPoint::DIAG, uniqueId++};
            newA.insert(dpA);
            newB.insert(dpB);
        }
    }

    for(auto& pB : B) {
        if (pB.isNormal()) {
            DgmPoint dpB {pB.getRealX(), pB.getRealY(), DgmPoint::NORMAL, uniqueId++};
            DgmPoint dpA {(pB.getRealX() +pB.getRealY())/2, (pB.getRealX() +pB.getRealY())/2, DgmPoint::DIAG, uniqueId++};
            newB.insert(dpB);
            newA.insert(dpA);
        }
    }

    A = newA;
    B = newB;
    A.isLinked = true;
    B.isLinked = true;
}


//#ifndef FOR_R_TDA

//template<class Real>
//std::ostream& operator<<(std::ostream& output, const DiagramPoint<Real>& p)
//{
//    if ( p.isDiagonal() ) {
//        output << "(" << p.x << ", " << p.y << ", " <<  0.5 * (p.x + p.y) << ", "  << p.id << " DIAG )";
//    } else {
//        output << "(" << p.x << ", " << p.y << ", " << p.id << " NORMAL)";
//    }
//    return output;
//}

//template<class Real>
//std::ostream& operator<<(std::ostream& output, const DiagramPointSet<Real>& ps)
//{
//    output << "{ ";
//    for(auto pit = ps.cbegin(); pit != ps.cend(); ++pit) {
//        output << *pit << ", ";
//    }
//    output << "\b\b }";
//    return output;
//}
//#endif // FOR_R_TDA


} // end namespace bt
} // end namespace hera
#endif  // HERA_BASIC_DEFS_BT_H