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

#ifndef QT3DRENDER_QBUFFER_H
#define QT3DRENDER_QBUFFER_H

#include <Qt3DCore/qnode.h>
#include <Qt3DRender/qt3drender_global.h>
#include <QSharedPointer>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

class QBufferPrivate;
class QBufferDataGenerator;
typedef QSharedPointer<QBufferDataGenerator> QBufferDataGeneratorPtr;

class QT3DRENDERSHARED_EXPORT QBuffer : public Qt3DCore::QNode
{
    Q_OBJECT
    Q_PROPERTY(BufferType type READ type WRITE setType NOTIFY typeChanged)
    Q_PROPERTY(UsageType usage READ usage WRITE setUsage NOTIFY usageChanged)
    Q_PROPERTY(bool syncData READ isSyncData WRITE setSyncData NOTIFY syncDataChanged)

public:
    enum BufferType
    {
        VertexBuffer        = 0x8892, // GL_ARRAY_BUFFER
        IndexBuffer         = 0x8893, // GL_ELEMENT_ARRAY_BUFFER
        PixelPackBuffer     = 0x88EB, // GL_PIXEL_PACK_BUFFER
        PixelUnpackBuffer   = 0x88EC, // GL_PIXEL_UNPACK_BUFFER
        UniformBuffer       = 0x8A11, // GL_UNIFORM_BUFFER
        ShaderStorageBuffer = 0x90D2  // GL_SHADER_STORAGE_BUFFER
    };
    Q_ENUM(BufferType)

    enum UsageType
    {
        StreamDraw          = 0x88E0, // GL_STREAM_DRAW
        StreamRead          = 0x88E1, // GL_STREAM_READ
        StreamCopy          = 0x88E2, // GL_STREAM_COPY
        StaticDraw          = 0x88E4, // GL_STATIC_DRAW
        StaticRead          = 0x88E5, // GL_STATIC_READ
        StaticCopy          = 0x88E6, // GL_STATIC_COPY
        DynamicDraw         = 0x88E8, // GL_DYNAMIC_DRAW
        DynamicRead         = 0x88E9, // GL_DYNAMIC_READ
        DynamicCopy         = 0x88EA  // GL_DYNAMIC_COPY
    };
    Q_ENUM(UsageType)

    explicit QBuffer(BufferType ty = QBuffer::VertexBuffer, Qt3DCore::QNode *parent = nullptr);
    ~QBuffer();

    UsageType usage() const;
    BufferType type() const;
    bool isSyncData() const;

    void setData(const QByteArray &bytes);
    QByteArray data() const;

    void setDataGenerator(const QBufferDataGeneratorPtr &functor);
    QBufferDataGeneratorPtr dataGenerator() const;

public Q_SLOTS:
    void setType(BufferType type);
    void setUsage(UsageType usage);
    void setSyncData(bool syncData);

protected:
    void sceneChangeEvent(const Qt3DCore::QSceneChangePtr &change) Q_DECL_OVERRIDE;

Q_SIGNALS:
    void dataChanged(const QByteArray &bytes);
    void typeChanged(BufferType type);
    void usageChanged(UsageType usage);
    void syncDataChanged(bool syncData);

private:
    Q_DECLARE_PRIVATE(QBuffer)
    Qt3DCore::QNodeCreatedChangeBasePtr createNodeCreationChange() const Q_DECL_OVERRIDE;
};

} // namespace Qt3DRender

QT_END_NAMESPACE

#endif // QT3DRENDER_QBUFFER_H
