/****************************************************************************

**

** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).

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** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtOpenGL module of the Qt Toolkit.

**

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

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**

** If you have questions regarding the use of this file, please contact

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** $QT_END_LICENSE$

**

****************************************************************************/

//

//  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 <QMultiHash>

#include <QObject>

#include <QtOpenGL/QtOpenGL>

#include <private/qgl_p.h>

QT_BEGIN_NAMESPACE

class QGL2GradientCache

{

    struct CacheInfo

    {

        inline CacheInfo(QGradientStops s, qreal op, QGradient::InterpolationMode mode) :

            stops(s), opacity(op), interpolationMode(mode) {}

        GLuint texId;

        QGradientStops stops;

        qreal opacity;

        QGradient::InterpolationMode interpolationMode;

    };

    typedef QMultiHash<quint64, CacheInfo> QGLGradientColorTableHash;

public:

    static QGL2GradientCache *cacheForContext(const QGLContext *context);

    QGL2GradientCache() { }

    ~QGL2GradientCache() {cleanCache();}

    GLuint getBuffer(const QGradient &gradient, qreal opacity);

    inline int paletteSize() const { return 1024; }

protected:

    inline int maxCacheSize() const { return 60; }

    inline void generateGradientColorTable(const QGradient& gradient,

                                           uint *colorTable,

                                           int size, qreal opacity) const;

    GLuint addCacheElement(quint64 hash_val, const QGradient &gradient, qreal opacity);

    void cleanCache();

    QGLGradientColorTableHash cache;

};

QT_END_NAMESPACE