eng_bsp.hh

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/*
 * LEGAL:   COPYRIGHT (C) 2007 JIM E. BROOKS
 *          THIS SOURCE CODE IS RELEASED UNDER THE TERMS
 *          OF THE GNU GENERAL PUBLIC LICENSE VERSION 2 (GPL 2).
 *****************************************************************************/

#ifndef ENG_BSP_HH
#define ENG_BSP_HH 1

namespace eng {

class Object;

class BSP
{

friend class Quadrant;
friend class World;

public:
    enum ePolicy
    {
        ePolicy_FORCE,  
        ePolicy_THROW_EXCEPTION
    };

//------------------------------------------------------------------------------
// Functor:
public:
    class ForEachObjectFunctor
    {
    public:
                        ForEachObjectFunctor( void ) { }
        virtual         ~ForEachObjectFunctor() { }
        virtual void    operator()( SharedPtr<Object> obj ) = 0;
    };

    void        ForEachObject( ForEachObjectFunctor& functor ); 

//------------------------------------------------------------------------------
// Viewpoint (defined appropriately for recursing a BSP tree).
private:
    class Viewpoint
    {
    public:
                    Viewpoint( void );
                    ~Viewpoint();
        fp Distance( const BoxVolume& boxVolume ) const
        {
            return gfx::Distance<WorldVertex,Vector3>( mPos, boxVolume.GetCenter() );
        }

    private:
        WorldVertex     mPos;  
    };

//------------------------------------------------------------------------------
// BSP Node:
private:
    class Node
    {
    
    public:
        typedef list< shptr<Object> > ObjectList;  // Dlist incompatible with SharedPtr
        typedef Node* Ptr;
    public:
                    Node( const BoxVolume& boxVolume );
                    ~Node();
        bool        IfInside( const WorldVertex& viewpoint ) const { return mBoxVolume.IfInside( viewpoint ); }
        bool        IfInside( const Volume& volume ) const { return mBoxVolume.IfInside( volume ); }
        bool        IfInside( const BoxVolume& boxVolume ) const { return mBoxVolume.IfInside( boxVolume ); }
        eAttached   Attach( SharedPtr<Object> object );
        eAttached   Detach( SharedPtr<Object> object );
        void        Draw( const BSP::Viewpoint& viewpoint );
        void        ForEachObject( BSP::ForEachObjectFunctor& functor );
        // Saves memory by lazy-allocation.  Not for use in testing if a node exists.
        ObjectList* GetOrNewObjectList( void )
        {
            return (mObjectList != NULL) ? mObjectList : (mObjectList = new ObjectList);
        }
    private:
        void        DrawVisit( void );

    public:
        BoxVolume       mBoxVolume;     
        Node::Ptr       mLeft;          
        Node::Ptr       mRight;         
    private:
        ObjectList*     mObjectList;    
        struct Bits                     
        {
            uint mObjectCnt            : 16;
            uint mObjectCntTranslucent : 16;
        };
        Bits            mBits;
        CLASS_CONST uint NODE_OBJECT_LIMIT = 0x7fff;  // 16 bits
    public:
        
    };

//------------------------------------------------------------------------------
// BSP interface:
public:
                BSP( const BoxVolume& boxVolume );
                ~BSP();
    CLASS_METHOD void SetPolicy( const ePolicy policy );
    // BoxVolume::IfInside() is faster than absract Volume::IfInside().
    bool        IfInside( const Volume& volume ) { return mRoot->IfInside( volume ); }
    bool        IfInside( const BoxVolume& boxVolume ) { return mRoot->IfInside( boxVolume ); }
    const BoxVolume& GetBoxVolume( void ) { return mRoot->mBoxVolume; }
    eAttached   Attach( SharedPtr<Object> object );
    eAttached   Detach( SharedPtr<Object> object );
    void        Draw( void );

//------------------------------------------------------------------------------
// BSP private methods:
private:
    BSP::Node::Ptr  FindFit( SharedPtr<Object> object );
    BSP::Node::Ptr  FindFit( const BoxVolume& objectVolume );

    bool IfContinueRecursion( const uint level )
    {
        return (level < msRecursionLimit) && (mNodeCnt < msNodeLimit);
    }

//------------------------------------------------------------------------------
// BSP data members:
public:
#if DEBUG
    CLASS_VAR uint      msDebugRecursionLevel;  // for testing
    CLASS_VAR bool      msDebugDrawBox;
#endif
private:
    CLASS_VAR uint      msRecursionLimit;   
    CLASS_VAR int       msNodeLimit;        
    CLASS_VAR ePolicy   msPolicy;
    Node::Ptr           mRoot;              
    int                 mNodeCnt;
};

//==============================================================================

class PolygonBSP
{
// STUB
};

//==============================================================================

class ExceptionBSP : public Exception
{
public:
    string  GetText( void ) const { return "BSP exception"; }
};

} // namespace eng

#endif // ENG_BSP_HH

Palomino 3D Engine documents generated by doxygen 1.5.3 on Fri Nov 23 11:26:07 2007