qpathclipper_p.h

奇趣公司比较新的qt/emd版本

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#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/qpainterpath.h>
#include <QtCore/qlist.h>

#include <private/qbezier_p.h>
#include <private/qdatabuffer_p.h>
#include <stdio.h>

QT_BEGIN_HEADER

QT_MODULE(Gui)

class Q_AUTOTEST_EXPORT QPathClipper
{
public:
    enum Operation {
        BoolAnd,
        BoolOr,
        BoolSub
    };
public:
    QPathClipper(const QPainterPath &subject,
                 const QPainterPath &clip);
    ~QPathClipper();

    QPainterPath clip(Operation op = BoolAnd);

    bool intersect();
    bool contains();

private:
    Q_DISABLE_COPY(QPathClipper)
    class Private;
    Private *d;
};

struct QPathVertex
{
public:
    QPathVertex(const QPointF &p = QPointF(), int e = -1);
    operator QPointF() const;

    int edge;

    qreal x;
    qreal y;
};

class QPathEdge
{
public:
    enum Traversal {
        RightTraversal,
        LeftTraversal
    };

    enum Direction {
        Forward,
        Backward
    };

    enum Type {
        Line,
        Curve
    };

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

    mutable int flag;

    int windingA;
    int windingB;

    int first;
    int second;

    qreal angle;
    qreal invAngle;

    const QBezier *bezier;
    qreal t0;
    qreal t1;

    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;

    bool isBezier() const;

private:
    int m_next[2][2];
};

class QPathSegments
{
public:
    QPathSegments();

    void setPath(const QPainterPath &path);

    int segments() const;

    const QLineF *lineAt(int index) const;
    const QBezier *bezierAt(int index) const;

    bool isAutoClosingLine(int index) const;

private:
    struct Line {
        Line(const QLineF &l, bool autoClosing = false)
            : line(l)
            , isAutoClosing(autoClosing)
        {
        }

        QLineF line;
        bool isAutoClosing;
    };

    QDataBuffer<QBezier> m_beziers;
    QDataBuffer<Line> m_lines;
};

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;

    QPathVertex *vertex(int vertex);
    const QPathVertex *vertex(int vertex) const;

    TraversalStatus next(const TraversalStatus &status) const;

    int addEdge(const QPointF &a, const QPointF &b, const QBezier *bezier = 0, qreal t0 = 0, qreal t1 = 1);

    bool isInside(qreal x, qreal y) const;

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

private:
    void intersectAndAdd(bool mightIntersect);

    void printNode(int i, FILE *handle);

    QBezier bezierFromIndex(int index) const;

    void removeEdge(int ei);
    void addBezierEdge(const QBezier *bezier, const QPointF &a, const QPointF &b, qreal alphaA, qreal alphaB, int path);

    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;

    QVector<qreal> m_splitPoints;

    QPathSegments m_clipSegments;
    QPathSegments m_subjectSegments;
};

inline QPathEdge::QPathEdge(int a, int b)
    : flag(0)
    , windingA(0)
    , windingB(0)
    , first(a)
    , second(b)
    , bezier(0)
{
    m_next[0][0] = -1;
    m_next[1][0] = -1;
    m_next[0][0] = -1;
    m_next[1][0] = -1;
}

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 bool QPathEdge::isBezier() const
{
    return bezier >= 0;
}

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()
{
}

inline int QPathSegments::segments() const
{
    return m_lines.size() + m_beziers.size();
}

inline const QLineF *QPathSegments::lineAt(int index) const
{
    if (index < m_lines.size())
        return &m_lines.at(index).line;
    else
        return 0;
}

inline const QBezier *QPathSegments::bezierAt(int index) const
{
    if (index >= m_lines.size())
        return &m_beziers.at(index - m_lines.size());
    else
        return 0;
}

inline bool QPathSegments::isAutoClosingLine(int index) const
{
    if (index < m_lines.size())
        return m_lines.at(index).isAutoClosing;
    else
        return false;
}

inline void QWingedEdge::TraversalStatus::flipDirection()
{
    direction = QWingedEdge::flip(direction);
}

inline void QWingedEdge::TraversalStatus::flipTraversal()
{
    traversal = QWingedEdge::flip(traversal);
}

inline void QWingedEdge::TraversalStatus::flip()
{
    flipDirection();
    flipTraversal();
}

inline int QWingedEdge::edgeCount() const
{
    return m_edges.size();
}

inline QPathEdge *QWingedEdge::edge(int edge)
{
    return edge < 0 ? 0 : &m_edges.at(edge);
}

inline const QPathEdge *QWingedEdge::edge(int edge) const
{
    return edge < 0 ? 0 : &m_edges.at(edge);
}

inline int QWingedEdge::vertexCount() const
{
    return m_vertices.size();
}


inline QPathVertex *QWingedEdge::vertex(int vertex)
{
    return vertex < 0 ? 0 : &m_vertices.at(vertex);
}

inline const QPathVertex *QWingedEdge::vertex(int vertex) const
{
    return vertex < 0 ? 0 : &m_vertices.at(vertex);
}

inline QPathEdge::Traversal QWingedEdge::flip(QPathEdge::Traversal traversal)
{
    return traversal == QPathEdge::RightTraversal ? QPathEdge::LeftTraversal : QPathEdge::RightTraversal;
}

inline QPathEdge::Direction QWingedEdge::flip(QPathEdge::Direction direction)
{
    return direction == QPathEdge::Forward ? QPathEdge::Backward : QPathEdge::Forward;
}


QT_END_HEADER

#endif // QPATHCLIPPER_P_H