/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QML Shaders plugin of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** 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
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
** http://www.gnu.org/copyleft/gpl.html.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef SHADEREFFECTITEM_H
#define SHADEREFFECTITEM_H

#include <QDeclarativeItem>
#include <QtOpenGL>
#include "shadereffectsource.h"
#include "scenegraph/qsggeometry.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

class ShaderEffectItem : public QDeclarativeItem
{
    Q_OBJECT
    Q_INTERFACES(QDeclarativeParserStatus)
    Q_PROPERTY(QString fragmentShader READ fragmentShader WRITE setFragmentShader NOTIFY fragmentShaderChanged)
    Q_PROPERTY(QString vertexShader READ vertexShader WRITE setVertexShader NOTIFY vertexShaderChanged)
    Q_PROPERTY(bool blending READ blending WRITE setBlending NOTIFY blendingChanged)
    Q_PROPERTY(QSize meshResolution READ meshResolution WRITE setMeshResolution NOTIFY meshResolutionChanged)

public:
    ShaderEffectItem(QDeclarativeItem* parent = 0);
    ~ShaderEffectItem();

    virtual void componentComplete();
    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0);

    QString fragmentShader() const { return m_fragment_code; }
    void setFragmentShader(const QString &code);

    QString vertexShader() const { return m_vertex_code; }
    void setVertexShader(const QString &code);

    bool blending() const { return m_blending; }
    void setBlending(bool enable);

    QSize meshResolution() const { return m_meshResolution; }
    void setMeshResolution(const QSize &size);

    void preprocess();

Q_SIGNALS:
    void fragmentShaderChanged();
    void vertexShaderChanged();
    void blendingChanged();
    void activeChanged();
    void meshResolutionChanged();

protected:
    virtual void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry);

private Q_SLOTS:
    void changeSource(int index);
    void handleVisibilityChange();
    void markDirty();

private:
    void checkViewportUpdateMode();
    void renderEffect(QPainter *painter, const QMatrix4x4 &matrix);
    void updateEffectState(const QMatrix4x4 &matrix);
    void updateGeometry();
    void bindGeometry();
    void setSource(const QVariant &var, int index);
    void disconnectPropertySignals();
    void connectPropertySignals();
    void reset();
    void updateProperties();
    void updateShaderProgram();
    void lookThroughShaderCode(const QString &code);
    bool active() const { return m_active; }
    void setActive(bool enable);

private:
    QString m_fragment_code;
    QString m_vertex_code;
    QGLShaderProgram* m_program;
    QVector<const char *> m_attributeNames;
    QSet<QByteArray> m_uniformNames;
    QSize m_meshResolution;
    QSGGeometry m_geometry;

    struct SourceData
    {
        QSignalMapper *mapper;
        QPointer<ShaderEffectSource> source;
        QPointer<QDeclarativeItem> item;
        QByteArray name;
    };

    QVector<SourceData> m_sources;

    bool m_changed : 1;
    bool m_blending : 1;
    bool m_program_dirty : 1;
    bool m_active : 1;
    bool m_respectsMatrix : 1;
    bool m_respectsOpacity : 1;
    bool m_checkedViewportUpdateMode : 1;
    bool m_checkedOpenGL : 1;
    bool m_checkedShaderPrograms : 1;
    bool m_hasShaderPrograms : 1;
    bool m_mirrored : 1;
    bool m_defaultVertexShader : 1;

    QGLFramebufferObject* m_contextObserver;
};

QT_END_HEADER

QT_END_NAMESPACE

#endif // SHADEREFFECTITEM_H