/****************************************************************************
**
** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
** Copyright (C) 2015 The Qt Company Ltd and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt3D module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL3$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPLv3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or later 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 2.0 requirements will be
** met: http://www.gnu.org/licenses/gpl-2.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#ifndef QT3DRENDER_RENDER_RENDERVIEW_H
#define QT3DRENDER_RENDER_RENDERVIEW_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/qparameter.h>
#include <Qt3DRender/qclearbuffer.h>
#include <Qt3DRender/private/renderer_p.h>
#include <Qt3DRender/private/cameralens_p.h>
#include <Qt3DRender/private/attachmentpack_p.h>
#include <Qt3DRender/private/handle_types_p.h>
#include <Qt3DRender/qparameter.h>

#include <Qt3DCore/private/qframeallocator_p.h>

// TODO: Move out once this is all refactored
#include <Qt3DRender/private/renderviewjobutils_p.h>

#include <QVector>
#include <QMutex>
#include <QColor>

QT_BEGIN_NAMESPACE

namespace Qt3DRender {

class QRenderPass;

namespace Render {

class Renderer;
class NodeManagers;
class RenderCommand;
class RenderPassFilter;
class TechniqueFilter;
class ViewportNode;
class Effect;
class RenderPass;

typedef QPair<ShaderUniform, QVariant> ActivePropertyContent;
typedef QPair<QString, ActivePropertyContent > ActiveProperty;

struct Q_AUTOTEST_EXPORT Plane
{
    explicit Plane(const QVector4D &planeEquation)
        : planeEquation(planeEquation)
        , normal(planeEquation.toVector3D().normalized())
        , d(planeEquation.w() / planeEquation.toVector3D().length())
    {}

    const QVector4D planeEquation;
    const QVector3D normal;
    const float d;
};

// This class is kind of analogous to RenderBin but I want to avoid trampling
// on that until we get this working

class Q_AUTOTEST_EXPORT RenderView
{
public:
    RenderView();
    ~RenderView();

    static void operator delete(void *ptr);
    static void operator delete(void *ptr, void *);

    // TODO: Add a way to specify a sort predicate for the RenderCommands
    void sort();

    void setRenderer(Renderer *renderer);
    inline void setSurfaceSize(const QSize &size) { m_surfaceSize = size; }
    inline Renderer *renderer() const { return m_renderer; }
    inline NodeManagers *nodeManagers() const { return m_manager; }

    inline void setAllocator(Qt3DCore::QFrameAllocator *allocator)
    {
        m_allocator = allocator;
        m_data = m_allocator->allocate<InnerData>();
        // If we have a viewMatrix pointer instead of directly a QMatrix4x4 object in RenderView
        // This allows us to keep the size of RenderView smaller and avoid huge block fragmentation
        //
        // TODO: Is this worth it here. We don't have that many RenderViews to iterate over. This
        // level of memory management would be better in Entity's matrices as they will
        // help cache performance during iteration
        m_data->m_viewMatrix = m_allocator->allocate<QMatrix4x4>();
        m_data->m_viewProjectionMatrix = m_allocator->allocate<QMatrix4x4>();
    }
    inline Qt3DCore::QFrameAllocator *allocator() const { return m_allocator; }

    inline void setRenderCamera(CameraLens *renderCamera) { m_data->m_renderCamera = renderCamera; }
    inline CameraLens *renderCamera() const { return m_data->m_renderCamera; }

    inline void setViewMatrix(const QMatrix4x4 &viewMatrix) { *(m_data->m_viewMatrix) = viewMatrix; }
    inline QMatrix4x4 viewmatrix() const { Q_ASSERT(m_data->m_viewMatrix); return *(m_data->m_viewMatrix); }

    inline void setViewProjectionMatrix(const QMatrix4x4 &viewProjectionMatrix) { *(m_data->m_viewProjectionMatrix) = viewProjectionMatrix; }
    inline QMatrix4x4 viewProjectionMatrix() const { return *(m_data->m_viewProjectionMatrix); }

    inline void setEyePosition(const QVector3D &eyePos) { m_data->m_eyePos = eyePos; }
    inline QVector3D eyePosition() const { return m_data->m_eyePos; }

    inline void appendLayerFilter(const QStringList &layers) { m_data->m_layers << layers; }
    inline QStringList layerFilters() const { return m_data->m_layers; }

    inline void setRenderPassFilter(const RenderPassFilter *rpFilter) { m_data->m_passFilter = rpFilter; }
    inline const RenderPassFilter *renderPassFilter() const { return m_data->m_passFilter; }

    inline void setTechniqueFilter(const TechniqueFilter *filter) { m_data->m_techniqueFilter = filter; }
    inline const TechniqueFilter *techniqueFilter() const { return m_data->m_techniqueFilter; }

    inline RenderStateSet *stateSet() const { return m_stateSet; }
    void setStateSet(RenderStateSet *stateSet) { m_stateSet = stateSet; }

    inline bool noDraw() const { return m_noDraw; }
    void setNoDraw(bool noDraw) { m_noDraw = noDraw; }

    inline bool frustumCulling() const { return m_frustumCulling; }
    void setFrustumCulling(bool frustumCulling) { m_frustumCulling = frustumCulling; }

    // TODO: Get rid of this overly complex memory management by splitting out the
    // InnerData as a RenderViewConfig struct. This can be created by setRenderViewConfigFromFrameGraphLeafNode
    // and passed along with the RenderView to the functions that populate the renderview
    inline void setViewport(const QRectF &vp)
    {
        if (!m_viewport) {
            Q_ASSERT(m_allocator);
            m_viewport = m_allocator->allocate<QRectF>();
            *m_viewport = QRectF(0.0f, 0.0f, 1.0f, 1.0f);
        }
        *m_viewport = vp;
    }
    inline QRectF viewport() const
    {
        if (!m_viewport) {
            Q_ASSERT(m_allocator);
            m_viewport = m_allocator->allocate<QRectF>();
            *m_viewport = QRectF(0.0f, 0.0f, 1.0f, 1.0f);
        }
        return *m_viewport;
    }

    inline void setClearColor(const QColor &c)
    {
        if (!m_clearColor) {
            Q_ASSERT(m_allocator);
            m_clearColor = m_allocator->allocate<QColor>();
            *m_clearColor = QColor(QColor::Invalid);
        }
        *m_clearColor = c;
    }
    inline QColor clearColor() const
    {
        if (!m_clearColor) {
            Q_ASSERT(m_allocator);
            m_clearColor = m_allocator->allocate<QColor>();
            *m_clearColor = QColor(QColor::Invalid);
        }
        return *m_clearColor;
    }

    inline void setClearBuffer(QClearBuffer::BufferType clearBuffer) { m_clearBuffer = clearBuffer; }
    inline QClearBuffer::BufferType clearBuffer() const { return m_clearBuffer; }

    void buildRenderCommands(Entity *preprocessedTreeRoot, const Plane *planes);
    QVector<RenderCommand *> commands() const { return m_commands; }
    void gatherLights(Entity *preprocessedTreeRoot);

    void addRenderAttachment(Attachment attachment) { m_attachmentPack.addAttachment(attachment); }
    void setDrawBuffers(const QList<QRenderAttachment::RenderAttachmentType> &drawBuffers) { m_attachmentPack.setDrawBuffers(drawBuffers); }
    const AttachmentPack &attachmentPack() const;

    void setRenderTargetHandle(HTarget renderTargetHandle) { m_renderTarget = renderTargetHandle; }
    HTarget renderTargetHandle() const { return m_renderTarget; }

    void addSortCriteria(const QList<Qt3DCore::QNodeId> &sortMethodUid) { m_data->m_sortingCriteria.append(sortMethodUid); }

    // Helps making the size of RenderView smaller
    // Contains all the data needed for the actual building of the RenderView
    // But that aren't used later by the Renderer
    struct InnerData {
        InnerData()
            : m_renderCamera(Q_NULLPTR)
            , m_techniqueFilter(Q_NULLPTR)
            , m_passFilter(Q_NULLPTR)
            , m_viewMatrix(Q_NULLPTR)
        {
        }
        CameraLens *m_renderCamera;
        const TechniqueFilter *m_techniqueFilter;
        const RenderPassFilter *m_passFilter;
        QMatrix4x4 *m_viewMatrix;
        QMatrix4x4 *m_viewProjectionMatrix;
        QStringList m_layers;
        QList<Qt3DCore::QNodeId> m_sortingCriteria;
        QVector3D m_eyePos;
        UniformBlockValueBuilder m_uniformBlockBuilder;
    };

    struct LightSource {
        LightSource() : entity(Q_NULLPTR) { }
        LightSource(Entity *entity, const QList<Light *> &lights)
            : entity(entity), lights(lights) { }
        Entity *entity;
        QList<Light *> lights;
    };

private:
    void setShaderAndUniforms(RenderCommand *command, RenderPass *pass, ParameterInfoList &parameters, const QMatrix4x4 &worldTransform,
                              const QVector<LightSource> &activeLightSources);

    Renderer *m_renderer;
    NodeManagers *m_manager;
    QSize m_surfaceSize;
    Qt3DCore::QFrameAllocator *m_allocator;

    InnerData *m_data;

    mutable QColor *m_clearColor;
    mutable QRectF *m_viewport;
    HTarget m_renderTarget;
    AttachmentPack m_attachmentPack;
    QClearBuffer::BufferType m_clearBuffer;
    RenderStateSet *m_stateSet;
    bool m_noDraw;
    bool m_frustumCulling;

    // We do not use pointers to RenderNodes or Drawable's here so that the
    // render aspect is free to change the drawables on the next frame whilst
    // the render thread is submitting these commands.
    QVector<RenderCommand *> m_commands;

    QVector<LightSource> m_lightSources;

    typedef QHash<QString, QUniformValue* (RenderView::*)(const QMatrix4x4& model) const> StandardUniformsPFuncsHash;
    static StandardUniformsPFuncsHash ms_standardUniformSetters;
    static StandardUniformsPFuncsHash initializeStandardUniformSetters();
    static QStringList ms_standardAttributesNames;
    static QStringList initializeStandardAttributeNames();

    QUniformValue *modelMatrix(const QMatrix4x4& model) const;
    QUniformValue *viewMatrix(const QMatrix4x4&) const;
    QUniformValue *projectionMatrix(const QMatrix4x4 &) const;
    QUniformValue *modelViewMatrix(const QMatrix4x4 &model) const;
    QUniformValue *modelViewProjectionMatrix(const QMatrix4x4 &model) const;
    QUniformValue *inverseModelMatrix(const QMatrix4x4 &model) const;
    QUniformValue *inverseViewMatrix(const QMatrix4x4 &) const;
    QUniformValue *inverseProjectionMatrix(const QMatrix4x4 &) const;
    QUniformValue *inverseModelViewMatrix(const QMatrix4x4 &model) const;
    QUniformValue *inverseModelViewProjectionMatrix(const QMatrix4x4 &model) const;
    QUniformValue *modelNormalMatrix(const QMatrix4x4 &model) const;
    QUniformValue *modelViewNormalMatrix(const QMatrix4x4 &model) const;
    QUniformValue *viewportMatrix(const QMatrix4x4 &model) const;
    QUniformValue *inverseViewportMatrix(const QMatrix4x4 &model) const;
    QUniformValue *time(const QMatrix4x4 &model) const;
    QUniformValue *eyePosition(const QMatrix4x4 &model) const;

    void setUniformValue(QUniformPack &uniformPack, const QString &name, const QVariant &value);
    void setStandardUniformValue(QUniformPack &uniformPack, const QString &glslName, const QString &name, const QMatrix4x4 &worldTransform);
    void setUniformBlockValue(QUniformPack &uniformPack,
                              Shader *shader,
                              const ShaderUniformBlock &block,
                              const QVariant &value);
    void setDefaultUniformBlockShaderDataValue(QUniformPack &uniformPack,
                                               Shader *shader,
                                               ShaderData *shaderData,
                                               const QString &structName);
    void buildSortingKey(RenderCommand *command);
};

} // namespace Render
} // namespace Qt3DRender

QT_END_NAMESPACE

#endif // QT3DRENDER_RENDER_RENDERVIEW_H