// Copyright (C) 2016 The Qt Company Ltd.

// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef QPATHCLIPPER_P_H

#define QPATHCLIPPER_P_H

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

//

#include <QtGui/private/qtguiglobal_p.h>

#include <QtGui/qpainterpath.h>

#include <QtCore/qlist.h>

#include <private/qbezier_p.h>

#include <private/qdatabuffer_p.h>

#include <stdio.h>

QT_BEGIN_NAMESPACE

class QWingedEdge;

class Q_GUI_EXPORT QPathClipper

{

public:

    enum Operation {

        BoolAnd,

        BoolOr,

        BoolSub,

        Simplify

    };

public:

    QPathClipper(const QPainterPath &subject,

                 const QPainterPath &clip);

    QPainterPath clip(Operation op = BoolAnd);

    bool intersect();

    bool contains();

    static bool pathToRect(const QPainterPath &path, QRectF *rect = nullptr);

    static QPainterPath intersect(const QPainterPath &path, const QRectF &rect);

private:

    Q_DISABLE_COPY_MOVE(QPathClipper)

    enum ClipperMode {

        ClipMode, // do the full clip

        CheckMode // for contains/intersects (only interested in whether the result path is non-empty)

    };

    bool handleCrossingEdges(QWingedEdge &list, qreal y, ClipperMode mode);

    bool doClip(QWingedEdge &list, ClipperMode mode);

    QPainterPath subjectPath;

    QPainterPath clipPath;

    Operation op;

    int aMask;

    int bMask;

};

struct QPathVertex

{

public:

    QPathVertex(const QPointF &p = QPointF(), int e = -1);

    operator QPointF() const;

    int edge;

    qreal x;

    qreal y;

};

Q_DECLARE_TYPEINFO(QPathVertex, Q_PRIMITIVE_TYPE);

class QPathEdge

{

public:

    enum Traversal {

        RightTraversal,

        LeftTraversal

    };

    enum Direction {

        Forward,

        Backward

    };

    enum Type {

        Line,

        Curve

    };

    explicit QPathEdge(int a = -1, int b = -1);

    mutable int flag;

    int windingA;

    int windingB;

    int first;

    int second;

    double angle;

    double invAngle;

    int next(Traversal traversal, Direction direction) const;

    void setNext(Traversal traversal, Direction direction, int next);

    void setNext(Direction direction, int next);

    Direction directionTo(int vertex) const;

    int vertex(Direction direction) const;

private:

    int m_next[2][2] = { { -1, -1 }, { -1, -1 } };

};

Q_DECLARE_TYPEINFO(QPathEdge, Q_PRIMITIVE_TYPE);

class QPathSegments

{

public:

    struct Intersection {

        qreal t;

        int vertex;

        int next;

        bool operator<(const Intersection &o) const {

            return t < o.t;

        }

    };

    friend class QTypeInfo<Intersection>;

    struct Segment {

        Segment(int pathId, int vertexA, int vertexB)

            : path(pathId)

            , va(vertexA)

            , vb(vertexB)

            , intersection(-1)

        {

        }

        int path;

        // vertices

        int va;

        int vb;

        // intersection index

        int intersection;

        QRectF bounds;

    };

    friend class QTypeInfo<Segment>;

    QPathSegments(int reserve);

    void setPath(const QPainterPath &path);

    void addPath(const QPainterPath &path);

    int intersections() const;

    int segments() const;

    int points() const;

    const Segment &segmentAt(int index) const;

    const QLineF lineAt(int index) const;

    const QRectF &elementBounds(int index) const;

    int pathId(int index) const;

    const QPointF &pointAt(int vertex) const;

    int addPoint(const QPointF &point);

    const Intersection *intersectionAt(int index) const;

    void addIntersection(int index, const Intersection &intersection);

    void mergePoints();

private:

    QDataBuffer<QPointF> m_points;

    QDataBuffer<Segment> m_segments;

    QDataBuffer<Intersection> m_intersections;

    int m_pathId;

};

Q_DECLARE_TYPEINFO(QPathSegments::Intersection, Q_PRIMITIVE_TYPE);

Q_DECLARE_TYPEINFO(QPathSegments::Segment, Q_PRIMITIVE_TYPE);

class Q_AUTOTEST_EXPORT QWingedEdge

{

public:

    struct TraversalStatus

    {

        int edge;

        QPathEdge::Traversal traversal;

        QPathEdge::Direction direction;

        void flipDirection();

        void flipTraversal();

        void flip();

    };

    QWingedEdge();

    QWingedEdge(const QPainterPath &subject, const QPainterPath &clip);

    void simplify();

    QPainterPath toPath() const;

    int edgeCount() const;

    QPathEdge *edge(int edge);

    const QPathEdge *edge(int edge) const;

    int vertexCount() const;

    int addVertex(const QPointF &p);

    QPathVertex *vertex(int vertex);

    const QPathVertex *vertex(int vertex) const;

    TraversalStatus next(const TraversalStatus &status) const;

    int addEdge(const QPointF &a, const QPointF &b);

    int addEdge(int vertexA, int vertexB);

    bool isInside(qreal x, qreal y) const;

    static QPathEdge::Traversal flip(QPathEdge::Traversal traversal);

    static QPathEdge::Direction flip(QPathEdge::Direction direction);

private:

    void intersectAndAdd();

    void printNode(int i, FILE *handle);

    void removeEdge(int ei);

    int insert(const QPathVertex &vertex);

    TraversalStatus findInsertStatus(int vertex, int edge) const;

    qreal delta(int vertex, int a, int b) const;

    QDataBuffer<QPathEdge> m_edges;

    QDataBuffer<QPathVertex> m_vertices;

    QList<qreal> m_splitPoints;

    QPathSegments m_segments;

};

inline QPathEdge::QPathEdge(int a, int b)

    : flag(0)

    , windingA(0)

    , windingB(0)

    , first(a)

    , second(b)

    , angle(0)

    , invAngle(0)

{

}

inline int QPathEdge::next(Traversal traversal, Direction direction) const

{

    return m_next[int(traversal)][int(direction)];

}

inline void QPathEdge::setNext(Traversal traversal, Direction direction, int next)

{

    m_next[int(traversal)][int(direction)] = next;

}

inline void QPathEdge::setNext(Direction direction, int next)

{

    m_next[0][int(direction)] = next;

    m_next[1][int(direction)] = next;

}

inline QPathEdge::Direction QPathEdge::directionTo(int vertex) const

{

    return first == vertex ? Backward : Forward;

}

inline int QPathEdge::vertex(Direction direction) const

{

    return direction == Backward ? first : second;

}

inline QPathVertex::QPathVertex(const QPointF &p, int e)

    : edge(e)

    , x(p.x())

    , y(p.y())

{

}

inline QPathVertex::operator QPointF() const

{

    return QPointF(x, y);

}

inline QPathSegments::QPathSegments(int reserve) :

    m_points(reserve),

    m_segments(reserve),

    m_intersections(reserve),

    m_pathId(0)

{

}

inline int QPathSegments::segments() const

{

    return m_segments.size();

}

inline int QPathSegments::points() const

{

    return m_points.size();

}

inline const QPointF &QPathSegments::pointAt(int i) const

{

    return m_points.at(i);

}

inline int QPathSegments::addPoint(const QPointF &point)

{

    m_points << point;

    return m_points.size() - 1;

}

inline const QPathSegments::Segment &QPathSegments::segmentAt(int index) const

{

    return m_segments.at(index);

}

inline const QLineF QPathSegments::lineAt(int index) const

{

    const Segment &segment = m_segments.at(index);

    return QLineF(m_points.at(segment.va), m_points.at(segment.vb));

}

inline const QRectF &QPathSegments::elementBounds(int index) const

{

    return m_segments.at(index).bounds;

}

inline int QPathSegments::pathId(int index) const

{

    return m_segments.at(index).path;

}

inline const QPathSegments::Intersection *QPathSegments::intersectionAt(int index) const

{

    const int intersection = m_segments.at(index).intersection;

    if (intersection < 0)

        return nullptr;

    else

        return &m_intersections.at(intersection);

}

inline int QPathSegments::intersections() const

{

    return m_intersections.size();

}

inline void QPathSegments::addIntersection(int index, const Intersection &intersection)

{

    m_intersections << intersection;

    Segment &segment = m_segments.at(index);

    if (segment.intersection < 0) {

        segment.intersection = m_intersections.size() - 1;

    } else {

        Intersection *isect = &m_intersections.at(segment.intersection);

        while (isect->next != 0)

            isect += isect->next;

        isect->next = (m_intersections.size() - 1) - (isect - m_intersections.data());

    }

}

inline int QWingedEdge::edgeCount() const

{

    return m_edges.size();

}

inline QPathEdge *QWingedEdge::edge(int edge)

{

    return edge < 0 ? nullptr : &m_edges.at(edge);

}

inline const QPathEdge *QWingedEdge::edge(int edge) const

{

    return edge < 0 ? nullptr : &m_edges.at(edge);

}

inline int QWingedEdge::vertexCount() const

{

    return m_vertices.size();

}

inline int QWingedEdge::addVertex(const QPointF &p)

{

    m_vertices << p;

    return m_vertices.size() - 1;

}

inline QPathVertex *QWingedEdge::vertex(int vertex)

{

    return vertex < 0 ? nullptr : &m_vertices.at(vertex);

}

inline const QPathVertex *QWingedEdge::vertex(int vertex) const

{

    return vertex < 0 ? nullptr : &m_vertices.at(vertex);

}

inline QPathEdge::Traversal QWingedEdge::flip(QPathEdge::Traversal traversal)

{

    return traversal == QPathEdge::RightTraversal ? QPathEdge::LeftTraversal : QPathEdge::RightTraversal;

}

inline void QWingedEdge::TraversalStatus::flipTraversal()

{

    traversal = QWingedEdge::flip(traversal);

}

inline QPathEdge::Direction QWingedEdge::flip(QPathEdge::Direction direction)

{

    return direction == QPathEdge::Forward ? QPathEdge::Backward : QPathEdge::Forward;

}

inline void QWingedEdge::TraversalStatus::flipDirection()

{

    direction = QWingedEdge::flip(direction);

}

inline void QWingedEdge::TraversalStatus::flip()

{

    flipDirection();

    flipTraversal();

}

QT_END_NAMESPACE

#endif // QPATHCLIPPER_P_H