/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/

#ifndef plSpaceTree_inc
#define plSpaceTree_inc

#include "hsTemplates.h"
#include "hsBounds.h"
#include "pnFactory/plCreatable.h"
#include "hsBitVector.h"

class hsStream;
class hsResMgr;
class plVolumeIsect;

class plSpaceTreeNode 
{
public:
    enum {
        kNone           = 0x0,
        kIsLeaf         = 0x1,
        kDirty          = 0x2,
        kDisabled       = 0x4,
        kEmpty          = 0x8,
        kEnabledTemp    = 0x10
    };

    hsBounds3Ext        fWorldBounds;

    UInt16              fFlags; // mostly for alignment;
    Int16               fParent;
    union {
        Int16               fChildren[2]; // Children are actually in same array as parent
        Int16               fLeafIndex;
    };

    Int16               GetChild(int w) const { hsAssert(!(fFlags & kIsLeaf), "Getting Child of leaf node"); return fChildren[w]; }
    Int16               GetParent() const { return fParent; }
    Int16               GetLeaf() const { hsAssert(fFlags & kIsLeaf, "Getting leaf idx off interior node"); return fLeafIndex; }
    hsBool              IsLeaf() const { return 0 != (fFlags & kIsLeaf); }
    const hsBounds3Ext& GetWorldBounds() const { return fWorldBounds; }

    // Kind of hate this. Would like to blast the whole thing in, but
    // the bounds are a real class.
    void                Read(hsStream* s);
    void                Write(hsStream* s);
};


class plSpaceTree : public plCreatable
{
public:
    enum plHarvestFlags {
        kNone                   = 0x0,
        kSortBackToFront        = 0x1,
        kSortFrontToBack        = 0x2
    };
    enum {
        kRootParent = -1
    };
private:
    hsTArray<plSpaceTreeNode>       fTree;
    const hsBitVector*              fCache;

    Int16                           fRoot;
    Int16                           fNumLeaves;

    UInt16                          fHarvestFlags;

    mutable plVolumeIsect*          fCullFunc;

    hsPoint3                        fViewPos;

    void        IRefreshRecur(Int16 which);
    
    void        IHarvestAndCullLeaves(const plSpaceTreeNode& subRoot, hsTArray<Int16>& list) const;
    void        IHarvestLeaves(const plSpaceTreeNode& subRoot, hsTArray<Int16>& list) const;
    
    void        IHarvestAndCullLeaves(const plSpaceTreeNode& subRoot, hsBitVector& totList, hsBitVector& list) const;
    void        IHarvestLeaves(const plSpaceTreeNode& subRoot, hsBitVector& totList, hsBitVector& list) const;

    void        IHarvestLevel(Int16 subRoot, int level, int currLevel, hsTArray<Int16>& list) const;

    void        IHarvestAndCullEnabledLeaves(Int16 subRoot, const hsBitVector& cache, hsTArray<Int16>& list) const;
    void        IHarvestEnabledLeaves(Int16 subRoot, const hsBitVector& cache, hsTArray<Int16>& list) const;
    void        IHarvestEnabledLeaves(Int16 subIdx, const hsBitVector& cache, hsBitVector& totList, hsBitVector& list) const;

    void        IEnableLeaf(Int16 idx, hsBitVector& cache) const;

public:
    plSpaceTree();
    virtual ~plSpaceTree();

    CLASSNAME_REGISTER( plSpaceTree );
    GETINTERFACE_ANY( plSpaceTree, plCreatable );

    void SetViewPos(const hsPoint3& p) { fViewPos = p; }
    const hsPoint3& GetViewPos() const { return fViewPos; }

    const plSpaceTreeNode&  GetNode(Int16 w) const { return fTree[w]; }
    Int16                   GetRoot() const { return fRoot; }
    hsBool                  IsRoot(Int16 w) const { return fRoot == w; }
    hsBool                  IsLeaf(Int16 w) const { return GetNode(w).IsLeaf(); }

    void HarvestLeaves(hsBitVector& totList, hsBitVector& list) const;
    void HarvestLeaves(hsBitVector& list) const;
    void HarvestLeaves(plVolumeIsect* cullFunc, hsBitVector& list) const;
    void HarvestLeaves(Int16 subRoot, hsBitVector& list) const;
    void HarvestLeaves(Int16 subRoot, hsBitVector& totList, hsBitVector& list) const;

    void HarvestLeaves(hsTArray<Int16>& list) const;
    void HarvestLeaves(plVolumeIsect* cullFunc, hsTArray<Int16>& list) const;
    void HarvestLeaves(Int16 subRoot, hsTArray<Int16>& list) const;

    void EnableLeaf(Int16 idx, hsBitVector& cache) const;
    void EnableLeaves(const hsTArray<Int16>& list, hsBitVector& cache) const;
    void HarvestEnabledLeaves(plVolumeIsect* cullFunc, const hsBitVector& cache, hsTArray<Int16>& list) const;
    void SetCache(const hsBitVector* cache) { fCache = cache; }

    void BitVectorToList(hsTArray<Int16>& list, const hsBitVector& bitVec) const;

    void SetHarvestFlags(plHarvestFlags f) { fHarvestFlags = f; }
    UInt16 GetHarvestFlags() const { return fHarvestFlags; }

    UInt16 HasLeafFlag(Int16 w, UInt16 f) const { return GetNode(w).fFlags & f; }
    void SetLeafFlag(Int16 w, UInt16 f, hsBool on=true);
    void ClearLeafFlag(Int16 w, UInt16 f);
    void ClearTreeFlag(UInt16 f);
    void SetTreeFlag(UInt16 f, hsBool on=true);

    hsBool IsDisabled(UInt16 w) const { return (GetNode(w).fFlags & plSpaceTreeNode::kDisabled) || (fCache && !fCache->IsBitSet(w)); }

    // Should GetWorldBounds check and refresh if needed?
    const hsBounds3Ext& GetWorldBounds() const { return GetNode(GetRoot()).fWorldBounds; }

    void MoveLeaf(Int16 idx, const hsBounds3Ext& newWorldBnd);
    void Refresh();
    hsBool IsEmpty() const { return 0 != (GetNode(GetRoot()).fFlags & plSpaceTreeNode::kEmpty); }
    hsBool IsDirty() const { return 0 != (GetNode(GetRoot()).fFlags & plSpaceTreeNode::kDirty); }
    void MakeDirty() { fTree[GetRoot()].fFlags |= plSpaceTreeNode::kDirty; }

    Int16 GetNumLeaves() const { return fNumLeaves; }

    virtual void Read(hsStream* s, hsResMgr* mgr);
    virtual void Write(hsStream* s, hsResMgr* mgr);

    void HarvestLevel(int level, hsTArray<Int16>& list) const;

    friend class plSpaceTreeMaker;
};

#endif // plSpaceTree_inc