// 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 QPAINTERPATH_P_H

#define QPAINTERPATH_P_H

//

//  W A R N I N G

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

//

// This file is not part of the Qt API.  It exists for the convenience

// of other Qt classes.  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 "QtGui/qregion.h"

#include "QtCore/qlist.h"

#include "QtCore/qshareddata.h"

#include "QtCore/qvarlengtharray.h"

#include <private/qvectorpath_p.h>

#include <private/qstroker_p.h>

#include <private/qbezier_p.h>

#include <memory>

QT_BEGIN_NAMESPACE

class QPolygonF;

class QVectorPathConverter;

class QVectorPathConverter

{

public:

    QVectorPathConverter(const QList<QPainterPath::Element> &path, bool hasWindingFill, bool convex)

        : pathData(path, hasWindingFill, convex),

          path(pathData.points.data(), path.size(), pathData.elements.data(), pathData.flags)

    {

    }

    const QVectorPath &vectorPath() {

        return path;

    }

    struct QVectorPathData {

        QVectorPathData(const QList<QPainterPath::Element> &path, bool hasWindingFill, bool convex)

            : elements(path.size()), points(path.size() * 2), flags(0)

        {

            int ptsPos = 0;

            bool isLines = true;

            for (int i=0; i<path.size(); ++i) {

                const QPainterPath::Element &e = path.at(i);

                elements[i] = e.type;

                points[ptsPos++] = e.x;

                points[ptsPos++] = e.y;

                if (e.type == QPainterPath::CurveToElement)

                    flags |= QVectorPath::CurvedShapeMask;

                // This is to check if the path contains only alternating lineTo/moveTo,

                // in which case we can set the LinesHint in the path. MoveTo is 0 and

                // LineTo is 1 so the i%2 gets us what we want cheaply.

                isLines = isLines && e.type == (QPainterPath::ElementType) (i%2);

            }

            if (hasWindingFill)

                flags |= QVectorPath::WindingFill;

            else

                flags |= QVectorPath::OddEvenFill;

            if (isLines)

                flags |= QVectorPath::LinesShapeMask;

            else {

                flags |= QVectorPath::AreaShapeMask;

                if (!convex)

                    flags |= QVectorPath::NonConvexShapeMask;

            }

        }

        QVarLengthArray<QPainterPath::ElementType> elements;

        QVarLengthArray<qreal> points;

        uint flags;

    };

    QVectorPathData pathData;

    QVectorPath path;

private:

    Q_DISABLE_COPY_MOVE(QVectorPathConverter)

};

class QPainterPathPrivate : public QSharedData

{

public:

    friend class QPainterPath;

    friend class QPainterPathStroker;

    friend class QPainterPathStrokerPrivate;

    friend class QTransform;

    friend class QVectorPath;

#ifndef QT_NO_DATASTREAM

    friend Q_GUI_EXPORT QDataStream &operator<<(QDataStream &, const QPainterPath &);

    friend Q_GUI_EXPORT QDataStream &operator>>(QDataStream &, QPainterPath &);

#endif

    QPainterPathPrivate() noexcept

        : QSharedData(),

          require_moveTo(false),

          dirtyBounds(false),

          dirtyControlBounds(false),

          convex(false),

          hasWindingFill(false),

          cacheEnabled(false)

    {

    }

    QPainterPathPrivate(QPointF startPoint)

        : QSharedData(),

          elements{ { startPoint.x(), startPoint.y(), QPainterPath::MoveToElement } },

          bounds(startPoint, QSizeF(0, 0)),

          controlBounds(startPoint, QSizeF(0, 0)),

          require_moveTo(false),

          dirtyBounds(false),

          dirtyControlBounds(false),

          convex(false),

          hasWindingFill(false),

          cacheEnabled(false)

    {

    }

    QPainterPathPrivate(const QPainterPathPrivate &other) noexcept

        : QSharedData(other),

          elements(other.elements),

          m_runLengths(other.m_runLengths),

          bounds(other.bounds),

          controlBounds(other.controlBounds),

          cStart(other.cStart),

          require_moveTo(false),

          dirtyBounds(other.dirtyBounds),

          dirtyControlBounds(other.dirtyControlBounds),

          dirtyRunLengths(other.dirtyRunLengths),

          convex(other.convex),

          hasWindingFill(other.hasWindingFill),

          cacheEnabled(other.cacheEnabled)

    {

    }

    QPainterPathPrivate &operator=(const QPainterPathPrivate &) = delete;

    ~QPainterPathPrivate() = default;

    inline bool isClosed() const;

    inline void close();

    inline void maybeMoveTo();

    inline void clear();

    QPointF endPointOfElement(int elemIdx) const;

    void computeRunLengths();

    int elementAtLength(qreal len);

    int elementAtT(qreal t);

    QBezier bezierAtT(const QPainterPath &path, qreal t, qreal *startingLength,

                      qreal *bezierLength) const;

    enum TrimFlags {

        TrimStart = 0x01,

        TrimEnd = 0x02

    };

    void appendTrimmedElement(QPainterPath *to, int elemIdx, int trimFlags, qreal startLen, qreal endLen);

    void appendStartOfElement(QPainterPath *to, int elemIdx, qreal len)

    {

        appendTrimmedElement(to, elemIdx, TrimEnd, 0, len);

    }

    void appendEndOfElement(QPainterPath *to, int elemIdx, qreal len)

    {

        appendTrimmedElement(to, elemIdx, TrimStart, len, 0);

    }

    void appendSliceOfElement(QPainterPath *to, int elemIdx, qreal fromLen, qreal toLen)

    {

        appendTrimmedElement(to, elemIdx, TrimStart | TrimEnd, fromLen, toLen);

    }

    void appendElementRange(QPainterPath *to, int first, int last);

    const QVectorPath &vectorPath() {

        if (!pathConverter)

            pathConverter.reset(new QVectorPathConverter(elements, hasWindingFill, convex));

        return pathConverter->path;

    }

private:

    QList<QPainterPath::Element> elements;

    std::unique_ptr<QVectorPathConverter> pathConverter;

    QList<qreal> m_runLengths;

    QRectF bounds;

    QRectF controlBounds;

    int cStart = 0;

    bool require_moveTo : 1;

    bool dirtyBounds : 1;

    bool dirtyControlBounds : 1;

    bool dirtyRunLengths : 1;

    bool convex : 1;

    bool hasWindingFill : 1;

    bool cacheEnabled : 1;

};

class QPainterPathStrokerPrivate

{

public:

    QPainterPathStrokerPrivate();

    QStroker stroker;

    QList<qfixed> dashPattern;

    qreal dashOffset;

};

inline const QPainterPath QVectorPath::convertToPainterPath() const

{

        QPainterPath path;

        path.ensureData();

        QPainterPathPrivate *data = path.d_func();

        data->elements.reserve(m_count);

        int index = 0;

        data->elements[0].x = m_points[index++];

        data->elements[0].y = m_points[index++];

        if (m_elements) {

            data->elements[0].type = m_elements[0];

            for (int i=1; i<m_count; ++i) {

                QPainterPath::Element element;

                element.x = m_points[index++];

                element.y = m_points[index++];

                element.type = m_elements[i];

                data->elements << element;

            }

        } else {

            data->elements[0].type = QPainterPath::MoveToElement;

            for (int i=1; i<m_count; ++i) {

                QPainterPath::Element element;

                element.x = m_points[index++];

                element.y = m_points[index++];

                element.type = QPainterPath::LineToElement;

                data->elements << element;

            }

        }

        data->hasWindingFill = !(m_hints & OddEvenFill);

        return path;

}

void Q_GUI_EXPORT qt_find_ellipse_coords(const QRectF &r, qreal angle, qreal length,

                                         QPointF* startPoint, QPointF *endPoint);

inline bool QPainterPathPrivate::isClosed() const

{

    const QPainterPath::Element &first = elements.at(cStart);

    const QPainterPath::Element &last = elements.last();

    return first.x == last.x && first.y == last.y;

}

inline void QPainterPathPrivate::close()

{

    Q_ASSERT(ref.loadRelaxed() == 1);

    require_moveTo = true;

    const QPainterPath::Element &first = elements.at(cStart);

    QPainterPath::Element &last = elements.last();

    if (first.x != last.x || first.y != last.y) {

        if (qFuzzyCompare(first.x, last.x) && qFuzzyCompare(first.y, last.y)) {

            last.x = first.x;

            last.y = first.y;

        } else {

            QPainterPath::Element e = { first.x, first.y, QPainterPath::LineToElement };

            elements << e;

        }

    }

}

inline void QPainterPathPrivate::maybeMoveTo()

{

    if (require_moveTo) {

        QPainterPath::Element e = elements.last();

        e.type = QPainterPath::MoveToElement;

        elements.append(e);

        require_moveTo = false;

    }

}

inline void QPainterPathPrivate::clear()

{

    Q_ASSERT(ref.loadRelaxed() == 1);

    elements.clear();

    m_runLengths.clear();

    cStart = 0;

    bounds = {};

    controlBounds = {};

    require_moveTo = false;

    dirtyBounds = false;

    dirtyControlBounds = false;

    dirtyRunLengths = false;

    convex = false;

    pathConverter.reset();

}

inline QPointF QPainterPathPrivate::endPointOfElement(int elemIdx) const

{

    const QPainterPath::Element &e = elements.at(elemIdx);

    if (e.isCurveTo())

        return elements.at(elemIdx + 2);

    else

        return e;

}

inline int QPainterPathPrivate::elementAtLength(qreal len)

{

    Q_ASSERT(cacheEnabled);

    Q_ASSERT(!dirtyRunLengths);

    const auto it = std::lower_bound(m_runLengths.constBegin(), m_runLengths.constEnd(), len);

    return (it == m_runLengths.constEnd()) ? m_runLengths.size() - 1 : int(it - m_runLengths.constBegin());

}

inline int QPainterPathPrivate::elementAtT(qreal t)

{

    Q_ASSERT(cacheEnabled);

    if (dirtyRunLengths)

        computeRunLengths();

    qreal len = t * m_runLengths.constLast();

    return elementAtLength(len);

}

#define KAPPA qreal(0.5522847498)

QT_END_NAMESPACE

#endif // QPAINTERPATH_P_H