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#ifndef QT3DRENDER_RENDER_PICKBOUNDINGVOLUMEUTILS_H
#define QT3DRENDER_RENDER_PICKBOUNDINGVOLUMEUTILS_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 <Qt3DCore/QNodeId>
#include <Qt3DRender/private/qray3d_p.h>
#include <Qt3DRender/private/trianglesvisitor_p.h>
#include <Qt3DRender/private/qraycastingservice_p.h>


QT_BEGIN_NAMESPACE

namespace Qt3DRender {
namespace RayCasting {
class QAbstractCollisionQueryService;
}

namespace Render {

class Entity;
class Renderer;
class FrameGraphNode;

namespace PickingUtils {

struct Q_AUTOTEST_EXPORT ViewportCameraAreaTriplet
{
    Qt3DCore::QNodeId cameraId;
    QRectF viewport;
    QSize area;
};
QT3D_DECLARE_TYPEINFO_3(Qt3DRender, Render, PickingUtils, ViewportCameraAreaTriplet, Q_PRIMITIVE_TYPE)

class Q_AUTOTEST_EXPORT ViewportCameraAreaGatherer
{
public:
    ViewportCameraAreaGatherer(const Qt3DCore::QNodeId &nodeId = Qt3DCore::QNodeId()) : m_targetCamera(nodeId) { }
    QVector<ViewportCameraAreaTriplet> gather(FrameGraphNode *root);

private:
    Qt3DCore::QNodeId m_targetCamera;
    QVector<FrameGraphNode *> m_leaves;

    void visit(FrameGraphNode *node);
    ViewportCameraAreaTriplet gatherUpViewportCameraAreas(Render::FrameGraphNode *node) const;
    bool isUnique(const QVector<ViewportCameraAreaTriplet> &vcaTriplets, const ViewportCameraAreaTriplet &vca) const;
};

class Q_AUTOTEST_EXPORT EntityGatherer
{
public:
    explicit EntityGatherer(Entity *root);

    QVector<Entity *> entities() const;

private:
    Entity *m_root;
    mutable QVector<Entity *> m_entities;
    mutable bool m_needsRefresh;
};

typedef QVector<RayCasting::QCollisionQueryResult::Hit> HitList;

class Q_AUTOTEST_EXPORT HierarchicalEntityPicker
{
public:
    explicit HierarchicalEntityPicker(const RayCasting::QRay3D &ray);

    bool collectHits(Entity *root);
    inline HitList hits() const { return m_hits; }
    inline QVector<Entity *> entities() const { return m_entities; }

private:
    RayCasting::QRay3D m_ray;
    HitList m_hits;
    QVector<Entity *> m_entities;
};

struct Q_AUTOTEST_EXPORT AbstractCollisionGathererFunctor
{
    AbstractCollisionGathererFunctor();
    virtual ~AbstractCollisionGathererFunctor();

    NodeManagers *m_manager;
    RayCasting::QRay3D m_ray;

    virtual HitList computeHits(const QVector<Entity *> &entities, bool allHitsRequested) = 0;

    // This define is required to work with QtConcurrent
    typedef HitList result_type;
    HitList operator ()(const Entity *entity) const;
    virtual HitList pick(const Entity *entity) const = 0;

    bool rayHitsEntity(const Entity *entity) const;
    static void sortHits(HitList &results);
};

struct Q_AUTOTEST_EXPORT EntityCollisionGathererFunctor : public AbstractCollisionGathererFunctor
{
    HitList computeHits(const QVector<Entity *> &entities, bool allHitsRequested) Q_DECL_OVERRIDE;
    HitList pick(const Entity *entity) const Q_DECL_OVERRIDE;
};

struct Q_AUTOTEST_EXPORT TriangleCollisionGathererFunctor : public AbstractCollisionGathererFunctor
{
    bool m_frontFaceRequested;
    bool m_backFaceRequested;

    HitList computeHits(const QVector<Entity *> &entities, bool allHitsRequested) Q_DECL_OVERRIDE;
    HitList pick(const Entity *entity) const Q_DECL_OVERRIDE;
};

} // PickingUtils

} // Render

} // Qt3DRender

QT_END_NAMESPACE

#endif // QT3DRENDER_RENDER_PICKBOUNDINGVOLUMEUTILS_H