GteSpatial.h

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// David Eberly, Geometric Tools, Redmond WA 98052
// Copyright (c) 1998-2017
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
// File Version: 3.0.0 (2016/06/19)

#pragma once

#include <Graphics/GteControlledObject.h>
#include <Graphics/GteCuller.h>
#include <string>

namespace gte
{

// Support for a spatial hierarchy of objects.  Class Spatial has a parent
// pointer.  Class Node derives from Spatial has an array of child pointers.
// The leaf nodes of the hierarchy are either graphical or audial.  Class
// Visual derives from Spatial and represents graphical data.  Class Audial
// derives from Spatial and represents sound data.

class Camera;

class GTE_IMPEXP Spatial : public ControlledObject
{
public:
    // Abstract base class.
    virtual ~Spatial();

    // Update of geometric state.  The function computes world transformations
    // on the downward pass of the scene graph traversal and world bounding
    // volumes on the upward pass of the traversal.  The object that calls the
    // update is the initiator.  Other objects visited during the update are
    // not initiators.  The application time is in milliseconds.
    void Update(double applicationTime = 0.0, bool initiator = true);

    // Access to the parent object, which is null for the root of the
    // hierarchy.
    inline Spatial* GetParent();

    // Allow user-readable names for nodes in a scene graph.
    std::string name;

    // Local and world transforms.  In some situations you might need to set
    // the world transform directly and bypass the Spatial::Update()
    // mechanism, in which case worldTransformIsCurrent should be set to
    // 'true'.
    Transform localTransform;
    Transform worldTransform;
    bool worldTransformIsCurrent;

    // World bound access.  In some situations you might want to set the
    // world bound directly and bypass the Spatial::Update() mechanism, in
    // which case worldBoundIsCurrent flag should be set to 'true'.
    BoundingSphere worldBound;
    CullingMode culling;
    bool worldBoundIsCurrent;

public:
    // Support for hierarchical culling.
    void OnGetVisibleSet(Culler& culler, std::shared_ptr<Camera> const& camera,
        bool noCull);
    virtual void GetVisibleSet(Culler& culler,
        std::shared_ptr<Camera> const& camera, bool noCull) = 0;

    // Access to the parent object.  Node calls this during attach/detach of
    // children.
    void SetParent(Spatial* parent);

protected:
    // Constructor accessible by Node, Visual, and Audial.
    Spatial();

    // Support for geometric updates.
    virtual void UpdateWorldData(double applicationTime);
    virtual void UpdateWorldBound() = 0;
    void PropagateBoundToRoot();

private:
    // Support for a hierarchical scene graph.  Spatial provides the parent
    // pointer.  Node provides the child pointers.  The parent pointer is not
    // shared to avoid reference-count cycles between mParent and 'this.
    // Because the pointer links are set internally rather than by an external
    // manager, it is not possible to use std::weak_ptr to avoid the cycle
    // because we do not know the shared_ptr object that owns mParent.
    Spatial* mParent;
};


inline Spatial* Spatial::GetParent()
{
    return mParent;
}

inline void Spatial::SetParent(Spatial* parent)
{
    mParent = parent;
}

}