// Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef QT3DRENDER_RENDER_SHADER_H
#define QT3DRENDER_RENDER_SHADER_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of other Qt classes.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <Qt3DRender/private/backendnode_p.h>
#include <Qt3DRender/qshaderprogram.h>

QT_BEGIN_NAMESPACE

class QOpenGLShaderProgram;

namespace Qt3DRender {

namespace Render {

class ShaderManager;
class AttachmentPack;

class Q_3DRENDERSHARED_PRIVATE_EXPORT Shader : public BackendNode
{
public:
    static const int modelMatrixNameId;
    static const int viewMatrixNameId;
    static const int projectionMatrixNameId;
    static const int modelViewMatrixNameId;
    static const int viewProjectionMatrixNameId;
    static const int modelViewProjectionNameId;
    static const int mvpNameId;
    static const int inverseModelMatrixNameId;
    static const int inverseViewMatrixNameId;
    static const int inverseProjectionMatrixNameId;
    static const int inverseModelViewNameId;
    static const int inverseViewProjectionMatrixNameId;
    static const int inverseModelViewProjectionNameId;
    static const int modelNormalMatrixNameId;
    static const int modelViewNormalNameId;
    static const int viewportMatrixNameId;
    static const int inverseViewportMatrixNameId;
    static const int textureTransformMatrixNameId;
    static const int aspectRatioNameId;
    static const int exposureNameId;
    static const int gammaNameId;
    static const int timeNameId;
    static const int eyePositionNameId;
    static const int skinningPaletteNameId;
    static const int yUpInFBOId;
    static const int yUpInNDCId;

    Shader();
    ~Shader();

    void cleanup();

    const std::vector<QByteArray> &shaderCode() const;
    void setShaderCode(QShaderProgram::ShaderType type, const QByteArray &code);

    void syncFromFrontEnd(const Qt3DCore::QNode *frontEnd, bool firstTime) override;

    inline QString log() const { return m_log; }
    inline QShaderProgram::Status status() const { return m_status; }

    void setFormat(QShaderProgram::Format format);
    QShaderProgram::Format format() const { return m_format; }
    bool isDirty() const { return m_dirty; }
    void unsetDirty() { m_dirty = false; }

    inline bool requiresFrontendSync() const { return m_requiresFrontendSync; }
    inline void unsetRequiresFrontendSync() { m_requiresFrontendSync = false; }

    // Set by Renderer plugin
    void setLog(const QString &log);
    void setStatus(QShaderProgram::Status status);
    void initializeFromReference(const Shader &other);

    void requestCacheRebuild();

private:
    std::vector<QByteArray> m_shaderCode;

    QString m_log;
    bool m_requiresFrontendSync;
    QShaderProgram::Status m_status;
    QShaderProgram::Format m_format;
    bool m_dirty;
};

#ifndef QT_NO_DEBUG_STREAM
inline QDebug operator<<(QDebug dbg, const Shader &shader)
{
    QDebugStateSaver saver(dbg);
    dbg << "QNodeId =" << shader.peerId() << Qt::endl;
    return dbg;
}
#endif

class Q_AUTOTEST_EXPORT ShaderFunctor : public Qt3DCore::QBackendNodeMapper
{
public:
    explicit ShaderFunctor(AbstractRenderer *renderer,
                           ShaderManager *manager);
    Qt3DCore::QBackendNode *create(Qt3DCore::QNodeId id) const final;
    Qt3DCore::QBackendNode *get(Qt3DCore::QNodeId id) const final;
    void destroy(Qt3DCore::QNodeId id) const final;

private:
    AbstractRenderer *m_renderer;
    ShaderManager *m_shaderManager;
};

} // namespace Render
} // namespace Qt3DRender

QT_END_NAMESPACE

#endif // QT3DRENDER_RENDER_SHADER_H