/*==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==*/

#include "hsTypes.h"
#include "plSpaceTree.h"
#include "hsStream.h"
#include "hsBitVector.h"
#include "plProfile.h"

#include "plIntersect/plVolumeIsect.h"
#include "plMath/hsRadixSort.h"

static hsBitVector scratchTotVec;
static hsBitVector scratchBitVec;
static hsTArray<Int16> scratchList;
static hsTArray<hsRadixSort::Elem> scratchSort;

plProfile_CreateCounter("Harvest Leaves", "Draw", HarvestLeaves);

void plSpaceTreeNode::Read(hsStream* s)
{
    fWorldBounds.Read(s);

    fFlags = s->ReadSwap16();
    fParent = s->ReadSwap16();
    fChildren[0] = s->ReadSwap16();
    fChildren[1] = s->ReadSwap16();

}

void plSpaceTreeNode::Write(hsStream* s)
{
    fWorldBounds.Write(s);

    s->WriteSwap16(fFlags);
    s->WriteSwap16(fParent);
    s->WriteSwap16(fChildren[0]);
    if( fFlags & kIsLeaf )
        // Temp for now to play nice with binary patches
        s->WriteSwap16( 0 );
    else
        s->WriteSwap16(fChildren[1]);
}

plSpaceTree::plSpaceTree()
:   fCullFunc(nil),
    fNumLeaves(0),
    fCache(nil)
{
}

plSpaceTree::~plSpaceTree()
{
}

void plSpaceTree::IRefreshRecur(Int16 which)
{
    plSpaceTreeNode& sub = fTree[which];

    if( sub.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        sub.fFlags &= ~plSpaceTreeNode::kDirty;
        return;
    }
    
    if( sub.fFlags & plSpaceTreeNode::kDirty )
    {
        IRefreshRecur(sub.fChildren[0]);
        IRefreshRecur(sub.fChildren[1]);

        sub.fWorldBounds.MakeEmpty();
        if( !(fTree[sub.fChildren[0]].fFlags & plSpaceTreeNode::kDisabled) )
            sub.fWorldBounds.Union(&fTree[sub.fChildren[0]].fWorldBounds);
        if( !(fTree[sub.fChildren[1]].fFlags & plSpaceTreeNode::kDisabled) )
            sub.fWorldBounds.Union(&fTree[sub.fChildren[1]].fWorldBounds);

        sub.fFlags &= ~plSpaceTreeNode::kDirty;
    }
}

void plSpaceTree::Refresh()
{
    if( !IsEmpty() )
        IRefreshRecur(fRoot);
}

void plSpaceTree::SetTreeFlag(UInt16 f, hsBool on)
{
    if( IsEmpty() )
        return;

    if( !on )
    {
        ClearTreeFlag(f);
        return;
    }

    int i;
    for( i = 0; i < fTree.GetCount(); i++ )
        fTree[i].fFlags |= f;
}

void plSpaceTree::ClearTreeFlag(UInt16 f)
{
    if( IsEmpty() )
        return;

    int i;
    for( i = 0; i < fTree.GetCount(); i++ )
        fTree[i].fFlags &= ~f;
}

void plSpaceTree::SetLeafFlag(Int16 idx, UInt16 f, hsBool on)
{
    if( IsEmpty() )
        return;

    hsAssert(idx == fTree[idx].fLeafIndex, "Some scrambling of indices");

    if( !on )
    {
        ClearLeafFlag(idx, f);
        return;
    }

    fTree[idx].fFlags |= f;

    idx = fTree[idx].fParent;

    while( idx != kRootParent )
    {
        if( (fTree[idx].fFlags & f)
            || !(fTree[fTree[idx].fChildren[0]].fFlags & fTree[fTree[idx].fChildren[1]].fFlags & f) )
        {
            idx = kRootParent;
        }
        else
        {
            fTree[idx].fFlags |= f;
            idx = fTree[idx].fParent;
        }
    }
}

void plSpaceTree::ClearLeafFlag(Int16 idx, UInt16 f)
{
    hsAssert(idx == fTree[idx].fLeafIndex, "Some scrambling of indices");

    while( idx != kRootParent )
    {
        if( !(fTree[idx].fFlags & f) )
        {
            return;
        }
        else
        {
            fTree[idx].fFlags &= ~f;
            idx = fTree[idx].fParent;
        }
    }

}

inline void plSpaceTree::IEnableLeaf(Int16 idx, hsBitVector& cache) const
{

    cache.SetBit(idx);

    idx = fTree[idx].fParent;

    while( idx != kRootParent )
    {
        if( cache.IsBitSet(idx) )
        {
            return;
        }
        else
        {
            cache.SetBit(idx);
            idx = fTree[idx].fParent;
        }
    }
}

void plSpaceTree::EnableLeaf(Int16 idx, hsBitVector& cache) const
{
    IEnableLeaf(idx, cache);
}

void plSpaceTree::EnableLeaves(const hsTArray<Int16>& list, hsBitVector& cache) const
{
    if( IsEmpty() )
        return;
    int i;
    for( i = 0; i < list.GetCount(); i++ )
    {
        IEnableLeaf(list[i], cache);
    }
}

void plSpaceTree::IHarvestAndCullEnabledLeaves(Int16 subIdx, const hsBitVector& cache, hsTArray<Int16>& list) const
{
    if( !cache.IsBitSet(subIdx) )
        return;

    const plSpaceTreeNode& subRoot = fTree[subIdx];

    plVolumeCullResult res = fCullFunc->Test(subRoot.fWorldBounds);
    if( res == kVolumeCulled )
        return;

    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        list.Append(subIdx);
    }
    else
    {
        if( res == kVolumeClear )
        {
            IHarvestEnabledLeaves(subRoot.fChildren[0], cache, list);
            IHarvestEnabledLeaves(subRoot.fChildren[1], cache, list);
        }
        else
        {
            IHarvestAndCullEnabledLeaves(subRoot.fChildren[0], cache, list);
            IHarvestAndCullEnabledLeaves(subRoot.fChildren[1], cache, list);
        }
    }
}

void plSpaceTree::IHarvestEnabledLeaves(Int16 subIdx, const hsBitVector& cache, hsTArray<Int16>& list) const
{
    if( !cache.IsBitSet(subIdx) )
        return;

    const plSpaceTreeNode& subRoot = fTree[subIdx];

    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        plProfile_Inc(HarvestLeaves);
        list.Append(subIdx);
    }
    else
    {
        IHarvestEnabledLeaves(subRoot.fChildren[0], cache, list);
        IHarvestEnabledLeaves(subRoot.fChildren[1], cache, list);
    }
}

void plSpaceTree::HarvestEnabledLeaves(plVolumeIsect* cull, const hsBitVector& cache, hsTArray<Int16>& list) const
{
    if( IsEmpty() )
        return;

    if( fCullFunc = cull )
        IHarvestAndCullEnabledLeaves(fRoot, cache, list);
    else
        IHarvestEnabledLeaves(fRoot, cache, list);
}

void plSpaceTree::IHarvestEnabledLeaves(Int16 subIdx, const hsBitVector& cache, hsBitVector& totList, hsBitVector& list) const
{
    if( IsDisabled(subIdx) )
        return;

    if( totList.IsBitSet(subIdx) )
        return;

    totList.SetBit(subIdx);

    const plSpaceTreeNode& subRoot = fTree[subIdx];
    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        plProfile_Inc(HarvestLeaves);
        list.SetBit(subIdx);
    }
    else
    {
        IHarvestEnabledLeaves(subRoot.fChildren[0], cache, totList, list);
        IHarvestEnabledLeaves(subRoot.fChildren[1], cache, totList, list);
    }
}

void plSpaceTree::MoveLeaf(Int16 idx, const hsBounds3Ext& bnd)
{
    hsAssert(idx == fTree[idx].fLeafIndex, "Some scrambling of indices");

    fTree[idx].fWorldBounds = bnd;

    while( idx != kRootParent )
    {
        if( fTree[idx].fFlags & plSpaceTreeNode::kDirty )
        {
            idx = kRootParent;
        }
        else
        {
            fTree[idx].fFlags |= plSpaceTreeNode::kDirty;
            idx = fTree[idx].fParent;
        }
    }
}

void plSpaceTree::HarvestLeaves(Int16 subRoot, hsBitVector& totList, hsBitVector& list) const
{
    if( !IsEmpty() )
    {
        if( fCache )
        {
            IHarvestEnabledLeaves(subRoot, *fCache, totList, list);
        }
        else
        {
            IHarvestLeaves(fTree[subRoot], totList, list);
        }
    }
}

void plSpaceTree::HarvestLeaves(hsBitVector& totList, hsBitVector& list) const
{
    if( !IsEmpty() )
        IHarvestLeaves(fTree[fRoot], totList, list);
}

void plSpaceTree::HarvestLeaves(hsBitVector& list) const
{
    if( !IsEmpty() )
        IHarvestLeaves(fTree[fRoot], scratchTotVec, list);
    scratchTotVec.Clear();
}

void plSpaceTree::HarvestLeaves(plVolumeIsect* cull, hsBitVector& list) const
{
    if( !IsEmpty() )
    {
        if( fCullFunc = cull )
            IHarvestAndCullLeaves(fTree[fRoot], scratchTotVec, list);
        else
            IHarvestLeaves(fTree[fRoot], scratchTotVec, list);
    }
    scratchTotVec.Clear();
}

void plSpaceTree::HarvestLeaves(Int16 subRoot, hsBitVector& list) const 
{ 
    IHarvestLeaves(GetNode(subRoot), scratchTotVec, list);
    scratchTotVec.Clear();
}

void plSpaceTree::HarvestLeaves(plVolumeIsect* cull, hsTArray<Int16>& list) const
{
    if( !IsEmpty() )
    {
        scratchBitVec.Clear();
        HarvestLeaves(cull, scratchBitVec);

        BitVectorToList(list, scratchBitVec);
    }
}

void plSpaceTree::HarvestLeaves(hsTArray<Int16>& list) const 
{
    if( !IsEmpty() )
    {
        scratchBitVec.Clear();
        HarvestLeaves(scratchBitVec);

        BitVectorToList(list, scratchBitVec);
    }
}

void plSpaceTree::HarvestLeaves(Int16 subRoot, hsTArray<Int16>& list) const 
{ 
    if( !IsEmpty() )
    {
        scratchBitVec.Clear();

        HarvestLeaves(subRoot, scratchBitVec);

        BitVectorToList(list, scratchBitVec);
    }
}

void plSpaceTree::BitVectorToList(hsTArray<Int16>& list, const hsBitVector& bitVec) const
{
#if 0 // added func to bitvector
    int i;
    for( i = 0; i < fNumLeaves; i++ )
    {
        if( bitVec.IsBitSet(i) )
            list.Append(i);
    }
#else  // added func to bitvector
    bitVec.Enumerate(list);
#endif  // added func to bitvector
}

void plSpaceTree::IHarvestAndCullLeaves(const plSpaceTreeNode& subRoot, hsBitVector& totList, hsBitVector& list) const
{
    if( subRoot.fFlags & plSpaceTreeNode::kDisabled )
        return;

    int idx = &subRoot - &fTree[0];
    if( totList.IsBitSet(idx) )
        return;

    hsAssert(fCullFunc, "Oops");
    plVolumeCullResult res = fCullFunc->Test(subRoot.fWorldBounds);
    if( res == kVolumeCulled )
        return;

    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        totList.SetBit(idx);

        plProfile_Inc(HarvestLeaves);
        list.SetBit(subRoot.fLeafIndex);
    }
    else
    {
        if( res == kVolumeClear )
        {
            totList.SetBit(idx);

            IHarvestLeaves(fTree[subRoot.fChildren[0]], totList, list);
            IHarvestLeaves(fTree[subRoot.fChildren[1]], totList, list);
        }
        else
        {
            IHarvestAndCullLeaves(fTree[subRoot.fChildren[0]], totList, list);
            IHarvestAndCullLeaves(fTree[subRoot.fChildren[1]], totList, list);
        }
    }
}

void plSpaceTree::IHarvestAndCullLeaves(const plSpaceTreeNode& subRoot, hsTArray<Int16>& list) const
{
    if( subRoot.fFlags & plSpaceTreeNode::kDisabled )
        return;

    hsAssert(fCullFunc, "Oops");
    plVolumeCullResult res = fCullFunc->Test(subRoot.fWorldBounds);
    if( res == kVolumeCulled )
        return;

    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        plProfile_Inc(HarvestLeaves);
        list.Append(subRoot.fLeafIndex);
    }
    else
    {
        if( res == kVolumeClear )
        {
            IHarvestLeaves(fTree[subRoot.fChildren[0]], list);
            IHarvestLeaves(fTree[subRoot.fChildren[1]], list);
        }
        else
        {
            IHarvestAndCullLeaves(fTree[subRoot.fChildren[0]], list);
            IHarvestAndCullLeaves(fTree[subRoot.fChildren[1]], list);
        }
    }
}

void plSpaceTree::IHarvestLeaves(const plSpaceTreeNode& subRoot, hsBitVector& totList, hsBitVector& list) const
{
    if( subRoot.fFlags & plSpaceTreeNode::kDisabled )
        return;

    int idx = &subRoot - &fTree[0];
    if( totList.IsBitSet(idx) )
        return;

    totList.SetBit(idx);

    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        plProfile_Inc(HarvestLeaves);
        list.SetBit(subRoot.fLeafIndex);
    }
    else
    {
        IHarvestLeaves(fTree[subRoot.fChildren[0]], totList, list);
        IHarvestLeaves(fTree[subRoot.fChildren[1]], totList, list);
    }
}

void plSpaceTree::IHarvestLeaves(const plSpaceTreeNode& subRoot, hsTArray<Int16>& list) const
{
    if( subRoot.fFlags & plSpaceTreeNode::kDisabled )
        return;
    if( subRoot.fFlags & plSpaceTreeNode::kIsLeaf )
    {
        plProfile_Inc(HarvestLeaves);
        list.Append(subRoot.fLeafIndex);
    }
    else
    {
        IHarvestLeaves(fTree[subRoot.fChildren[0]], list);
        IHarvestLeaves(fTree[subRoot.fChildren[1]], list);
    }
}

void plSpaceTree::Read(hsStream* s, hsResMgr* mgr)
{
    plCreatable::Read(s, mgr);

    fRoot = s->ReadSwap16();

    fNumLeaves = UInt16(s->ReadSwap32());

    UInt32 n = s->ReadSwap32();
    fTree.SetCount(n);
    int i;
    for( i = 0; i < n; i++ )
        fTree[i].Read(s);
}

void plSpaceTree::Write(hsStream* s, hsResMgr* mgr)
{
    plCreatable::Write(s, mgr);

    s->WriteSwap16(fRoot);

    s->WriteSwap32(fNumLeaves);

    s->WriteSwap32(fTree.GetCount());
    int i;
    for( i = 0; i < fTree.GetCount(); i++ )
    {
        fTree[i].Write(s);
    }
}

// Some debug only stuff

void plSpaceTree::HarvestLevel(int level, hsTArray<Int16>& list) const
{
    if( !IsEmpty() )
    {
        IHarvestLevel(fRoot, level, 0, list);
    }
}

void plSpaceTree::IHarvestLevel(Int16 subRoot, int level, int currLevel, hsTArray<Int16>& list) const
{
    if( level == currLevel )
    {
        list.Append(subRoot);
        return;
    }
    if( IsLeaf(subRoot) )
        return;

    IHarvestLevel(GetNode(subRoot).GetChild(0), level, currLevel+1, list);
    IHarvestLevel(GetNode(subRoot).GetChild(1), level, currLevel+1, list);
}