/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
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** This file is part of the QtQuick module of the Qt Toolkit.
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** accordance with the commercial license agreement provided with the
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****************************************************************************/

#ifndef QSGSHAREDDISTANCEFIELDGLYPHCACHE_H
#define QSGSHAREDDISTANCEFIELDGLYPHCACHE_H

#include <QtCore/qwaitcondition.h>
#include <private/qsgadaptationlayer_p.h>

QT_BEGIN_NAMESPACE

class QPlatformSharedGraphicsCache;
class QSGSharedDistanceFieldGlyphCache : public QObject, public QSGDistanceFieldGlyphCache
{
    Q_OBJECT
public:
    explicit QSGSharedDistanceFieldGlyphCache(const QByteArray &cacheId,
                                              QPlatformSharedGraphicsCache *sharedGraphicsCache,
                                              QSGDistanceFieldGlyphCacheManager *man,
                                              QOpenGLContext *c,
                                              const QRawFont &font);
    ~QSGSharedDistanceFieldGlyphCache();

    void registerOwnerElement(QQuickItem *ownerElement);
    void unregisterOwnerElement(QQuickItem *ownerElement);
    void processPendingGlyphs();

    void requestGlyphs(const QSet<glyph_t> &glyphs);
    void referenceGlyphs(const QSet<glyph_t> &glyphs);
    void storeGlyphs(const QList<QDistanceField> &glyphs);
    void releaseGlyphs(const QSet<glyph_t> &glyphs);

Q_SIGNALS:
    void glyphsPending();

private Q_SLOTS:
    void reportItemsMissing(const QByteArray &cacheId, const QVector<quint32> &itemIds);
    void reportItemsAvailable(const QByteArray &cacheId,
                              void *bufferId,
                              const QVector<quint32> &itemIds,
                              const QVector<QPoint> &positions);
    void reportItemsUpdated(const QByteArray &cacheId,
                            void *bufferId,
                            const QVector<quint32> &itemIds,
                            const QVector<QPoint> &positions);
    void reportItemsInvalidated(const QByteArray &cacheId, const QVector<quint32> &itemIds);

    void sceneGraphUpdateStarted();
    void sceneGraphUpdateDone();

private:
    void waitForGlyphs();
    void saveTexture(GLuint textureId, int width, int height);

    QSet<quint32> m_requestedGlyphsThatHaveNotBeenReturned;
    QSet<quint32> m_requestedGlyphs;
    QWaitCondition m_pendingGlyphsCondition;
    QByteArray m_cacheId;
    QPlatformSharedGraphicsCache *m_sharedGraphicsCache;
    QMutex m_pendingGlyphsMutex;

    QSet<glyph_t> m_pendingInvalidatedGlyphs;
    QSet<glyph_t> m_pendingMissingGlyphs;

    struct PendingGlyph
    {
        PendingGlyph() : buffer(0) {}

        void *buffer;
        QSize bufferSize;
        QPoint position;
    };

    struct Owner
    {
        Owner() : ref(0) {}
        Owner(const Owner &o) : item(o.item), ref(o.ref) {}
        Owner &operator =(const Owner &o) { item = o.item; ref = o.ref; return *this; }

        QPointer<QQuickItem> item;
        int ref;
    };

    QHash<quint32, PendingGlyph> m_pendingReadyGlyphs;
    QHash<glyph_t, void *> m_bufferForGlyph;
    QHash<QQuickItem *, Owner> m_registeredOwners;

    bool m_isInSceneGraphUpdate;
    bool m_hasPostedEvents;
};

QT_END_NAMESPACE

#endif // QSGSHAREDDISTANCEFIELDGLYPHCACHE_H
