/****************************************************************************
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** Copyright (C) 2015 The Qt Company Ltd.
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** This file is part of the QtGui module of the Qt Toolkit.
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** $QT_BEGIN_LICENSE:LGPL21$
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//
//  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.
//

#ifndef QOPENGLTEXTURECACHE_P_H
#define QOPENGLTEXTURECACHE_P_H

#include <QHash>
#include <QObject>
#include <QCache>
#include <private/qopenglcontext_p.h>
#include <QtCore/qmutex.h>

QT_BEGIN_NAMESPACE

class QOpenGLCachedTexture
{
public:
    QOpenGLCachedTexture(GLuint id, int options, QOpenGLContext *context);
    ~QOpenGLCachedTexture() { m_resource->free(); }

    GLuint id() const { return m_resource->id(); }
    int options() const { return m_options; }

private:
    QOpenGLSharedResourceGuard *m_resource;
    int m_options;
};

class Q_GUI_EXPORT QOpenGLTextureCache : public QOpenGLSharedResource
{
public:
    static QOpenGLTextureCache *cacheForContext(QOpenGLContext *context);

    QOpenGLTextureCache(QOpenGLContext *);
    ~QOpenGLTextureCache();

    enum BindOption {
        NoBindOption                            = 0x0000,
        PremultipliedAlphaBindOption            = 0x0001,
        UseRedFor8BitBindOption                 = 0x0002,
    };
    Q_DECLARE_FLAGS(BindOptions, BindOption)

    GLuint bindTexture(QOpenGLContext *context, const QPixmap &pixmap, QOpenGLTextureCache::BindOptions options = PremultipliedAlphaBindOption);
    GLuint bindTexture(QOpenGLContext *context, const QImage &image, QOpenGLTextureCache::BindOptions options = PremultipliedAlphaBindOption);

    void invalidate(qint64 key);

    void invalidateResource() Q_DECL_OVERRIDE;
    void freeResource(QOpenGLContext *ctx) Q_DECL_OVERRIDE;

private:
    GLuint bindTexture(QOpenGLContext *context, qint64 key, const QImage &image, QOpenGLTextureCache::BindOptions options);

    QMutex m_mutex;
    QCache<quint64, QOpenGLCachedTexture> m_cache;
};

Q_DECLARE_OPERATORS_FOR_FLAGS(QOpenGLTextureCache::BindOptions)

QT_END_NAMESPACE

#endif