/*==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/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

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 "HeadSpin.h"
#include "hsColorRGBA.h"
#include "hsGeometry3.h"
#include "hsResMgr.h"
#include "plTweak.h"

#include "MaxComponent/plComponent.h"

#include "MaxMain/MaxAPI.h"

#include "MaxMain/plMaxNode.h"
#include "MaxComponent/plLightGrpComponent.h"
#include "MaxComponent/plSoftVolumeComponent.h"

#include "plClusterUtil.h"

#include "plDrawable/plClusterGroup.h"
#include "plDrawable/plCluster.h"
#include "plDrawable/plSpanTemplate.h"
#include "plDrawable/plSpanInstance.h"
#include "plDrawable/plGeometrySpan.h"

#include "plSurface/hsGMaterial.h"
#include "plSurface/plLayer.h"
#include "plScene/plVisRegion.h"
#include "plGLight/plLightInfo.h"

#include "plMeshConverter.h"
#include "hsVertexShader.h"
#include "plLightMapGen.h"

#include "pnKeyedObject/plUoid.h"

#include "pnMessage/plNodeRefMsg.h"

plConst(int) kDefMinFaces(200);
plConst(int) kDefMaxFaces(1000);
plConst(float) kDefMinSize(50.f);

plClusterUtil::plClusterUtil()
:   fGroup(),
    fTemplNode(),
    fTemplate(),
    fMinFaces(kDefMinFaces),
    fMaxFaces(kDefMaxFaces),
    fMinSize(kDefMinSize),
    fIdx()
{
}

plClusterUtil::~plClusterUtil()
{
}

plClusterGroup* plClusterUtil::CreateGroup(plMaxNode* templNode, const ST::string& name)
{
    plClusterGroup* retVal = new plClusterGroup;
    
    ST::string buff = ST::format("{}_{}_{}", name, templNode->GetName(), fIdx++);
    hsgResMgr::ResMgr()->NewKey(buff, retVal, templNode->GetLocation(), templNode->GetLoadMask());

    plKey sceneNode = templNode->GetRoomKey();
    retVal->SetSceneNode(sceneNode);

    plNodeRefMsg* refMsg = new plNodeRefMsg(sceneNode, plRefMsg::kOnCreate, -1, plNodeRefMsg::kGeneric);
    hsgResMgr::ResMgr()->AddViaNotify(retVal->GetKey(), refMsg, plRefFlags::kActiveRef);

    return retVal;
}

plClusterGroup* plClusterUtil::SetupGroup(plClusterGroup *group, plMaxNode* templNode, plSpanTemplateB* templ)
{
    fTemplNode = templNode;
    fGroup = group;
    fTemplate = templ;

    fGroup->fTemplate = templ;
    fGroup->ISendToSelf(plClusterGroup::kRefMaterial, templ->fMaterial);

    fGroup->fRenderLevel = templ->fRenderLevel;

    fMinInsts = fMinFaces / templ->NumTris();
    fMaxInsts = fMaxFaces / templ->NumTris();
    if( fMinInsts < 1 )
        fMinInsts = 1;
    if( fMaxInsts <= fMinInsts )
        fMaxInsts = fMinInsts+1;

    // STUB
    // Finish setting up the group here (lights, visregions, LOD), extracting all info
    // from the template node.
    ISetupGroupFromTemplate(templNode);

    return fGroup;
}

void plClusterUtil::ISetupGroupFromTemplate(plMaxNode* templ)
{
    plLightGrpComponent* liGrp = plLightGrpComponent::GetComp(templ);
    if( liGrp )
    {
        const std::vector<plLightInfo*>& lights = liGrp->GetLightInfos();
        for (plLightInfo* light : lights)
            fGroup->ISendToSelf(plClusterGroup::kRefLight, light);
    }
    if( templ->HasFade() )
    {
        float maxDist = 0;
        float minDist = 0;

        Box3 fade = templ->GetFade();
        const float kMaxMaxDist = 1.e10f;
        if( fade.Min()[2] < 0 )
        {
            minDist = fade.Min()[0];
            maxDist = kMaxMaxDist;
        }

        if( fade.Max()[2] > 0 )
            maxDist = fade.Max()[0];

        if( maxDist > minDist )
        {
            fGroup->fLOD.Set(minDist, maxDist);
        }
    }
    std::vector<plVisRegion*> regions;
    plVisRegionComponent::CollectRegions(templ, regions);
    plEffVisSetComponent::CollectRegions(templ, regions);
    for (plVisRegion* region : regions)
        fGroup->ISendToSelf(plClusterGroup::kRefRegion, region);
}

class sortData
{
public:
    uint16_t          fIdx0;
    uint16_t          fIdx1;
    uint16_t          fIdx2;
    float        fDist;

    sortData() {}
    sortData(uint16_t idx0, uint16_t idx1, uint16_t idx2, float dist)
        : fIdx0(idx0), fIdx1(idx1), fIdx2(idx2), fDist(dist)
    {
    }

    bool operator<(const sortData& ot) const { return fDist < ot.fDist; }
    bool operator>(const sortData& ot) const { return fDist > ot.fDist; }
    bool operator==(const sortData& ot) const { return fDist == ot.fDist; }
    bool operator!=(const sortData& ot) const { return fDist != ot.fDist; }
};

void plClusterUtil::ISortTemplate(plSpanTemplateB* templ) const
{
    uint16_t* indexData = templ->fIndices;
    const int numTris = templ->NumTris();
    typedef std::vector<sortData> sortVec;
    sortVec vec;
    vec.resize(numTris);
    sortVec::iterator iter;
    for( iter = vec.begin(); iter != vec.end(); iter++ )
    {
        iter->fIdx0 = indexData[0];
        iter->fIdx1 = indexData[1];
        iter->fIdx2 = indexData[2];
        hsPoint3 pos;
        pos = *templ->Position(indexData[0]);
        float dist0 = pos.fX * pos.fX + pos.fY * pos.fY;
        pos = *templ->Position(indexData[1]);
        float dist1 = pos.fX * pos.fX + pos.fY * pos.fY;
        pos = *templ->Position(indexData[2]);
        float dist2 = pos.fX * pos.fX + pos.fY * pos.fY;

        iter->fDist = dist0 > dist1
            ? (dist0 > dist2
                ? dist0
                : dist2)
            : (dist1 > dist2
                ? dist1
                : dist2);

        indexData += 3;
    }

    std::sort(vec.begin(), vec.end(), std::less<sortData>());

    indexData = templ->fIndices;
    for( iter = vec.begin(); iter != vec.end(); iter++ )
    {
        indexData[0] = iter->fIdx0;
        indexData[1] = iter->fIdx1;
        indexData[2] = iter->fIdx2;
        
        indexData += 3;
    }
}

void plClusterUtil::ITemplateFromGeo(plSpanTemplateB* templ, plGeometrySpan* geo)
{
    uint16_t format = plSpanTemplate::MakeFormat(
        true, // hasColor
        geo->GetNumUVs(), // UVW count
        geo->fFormat & plGeometrySpan::kSkinIndices, // hasWgtIdx
        (geo->fFormat & plGeometrySpan::kSkinWeightMask) >> 4, // NumWeights
        true, // hasNorm
        true // hasPos;
        );
    

    uint32_t numVerts = geo->fNumVerts;
    uint32_t numTris = geo->fNumIndices / 3;
    
    // Alloc it.
    templ->Alloc(format, numVerts, numTris);
    templ->AllocColors();

    uint32_t numPos = templ->NumPos();
    uint32_t numNorm = templ->NumNorm();
    uint32_t numUVWs = templ->NumUVWs();
    uint32_t numWeights = templ->NumWeights();
    uint32_t numColor = templ->NumColor();
    uint32_t numColor2 = templ->NumColor2();
    uint32_t numWgtIdx = templ->NumWgtIdx();

    // Fill in the data.
    memcpy(templ->fIndices, geo->fIndexData, templ->IndexSize());

    int i;
    for( i = 0; i < templ->NumVerts(); i++ )
    {
        float wgt[4];
        uint32_t wgtIdx;

        geo->ExtractInitColor(i, templ->MultColor(i), templ->AddColor(i));

        hsColorRGBA color;
        geo->ExtractVertex(i, templ->Position(i), templ->Normal(i), &color);

        if( templ->NumColor() )
            *templ->Color(i) = color.ToARGB32();
        if( templ->NumColor2() )
            *templ->Color2(i) = 0; 

        int k;
        for( k = 0; k < templ->NumUVWs(); k++ )
        {
            geo->ExtractUv(i, k, templ->UVWs(i, k));
        }
        
        if( templ->NumWeights() )
        {
            geo->ExtractWeights(i, wgt, &wgtIdx);
            int j;
            for( j = 0; j < templ->NumWeights(); j++ )
                *templ->Weight(i, j) = wgt[j];
            if( templ->NumWgtIdx() )
                *templ->WgtIdx(i) = wgtIdx;
        }
    }

    // Compute the local bounds.
    templ->ComputeBounds();

    ISortTemplate(templ);
}

plSpanTemplateB* plClusterUtil::IAddTemplate(plMaxNode* templNode, plGeometrySpan* geo)
{
    // Shade our mesh.
    // STUB

    // Create our blank template
    plSpanTemplateB* templ = new plSpanTemplateB(templNode);

    templ->fRenderLevel = templNode->GetRenderLevel(!templNode->GetNoDeferDraw());

    ITemplateFromGeo(templ, geo);

    return templ;
}

void plClusterUtil::IAddTemplates(plMaxNode* templNode, plSpanTemplTab& templs)
{
    // STUB
    // Get the Mesh

    // Figure the format and total number of verts.
    // If we're lazy or pressed for time we could use MeshConverter.
    // But we'd probably spend more time undoing MeshConverter hacks than if we start
    // from scratch.
    // But, here we go descending cheerully into hell.
    // At least with this interface we can bail and do it right later without to much
    // bloodshed.
    std::vector<plGeometrySpan*> spanArray;
    if( !plMeshConverter::Instance().CreateSpans(templNode, spanArray, false) )
        return;

    plLightMapGen::Instance().Open(::GetCOREInterface(), ::GetCOREInterface()->GetTime(), false);
    hsVertexShader::Instance().Open();

    hsVertexShader::Instance().ShadeNode(templNode, 
                templNode->GetLocalToWorld44(), templNode->GetWorldToLocal44(), 
                spanArray);

    plLightMapGen::Instance().Close();
    hsVertexShader::Instance().Close();

    for (plGeometrySpan* span : spanArray)
    {
        plSpanTemplateB* templ = IAddTemplate(templNode, span);
        templs.Append(1, &templ);
        templ->fMaterial = span->fMaterial;

        delete span;
    }
}

Box3 plClusterUtil::IBound(const plL2WTab& src) const
{
    Box3 box;
    int i;
    for( i = 0; i < src.Count(); i++ )
    {
        box += src[i].GetTrans();
    }
    return box;
}

Point3 plClusterUtil::ILength(const plL2WTab& src) const
{
    Box3 box = IBound(src);
    return box.Max() - box.Min();
}

int plClusterUtil::ISelectAxis(const plL2WTab& src) const
{
    Box3 box = IBound(src);
    Point3 del = box.Max() - box.Min();
    if( del.x > del.y )
    {
        if( del.x > del.z )
            return 0;
        else
            return 2;
    }
    if( del.y > del.z )
        return 1;

    return 2;
}

static int sortAxis = 0;
static int cmp(const void *elem1, const void *elem2) 
{
    Matrix3* m1 = (Matrix3*) elem1;
    Matrix3* m2 = (Matrix3*) elem2;

    float d1 = m1->GetTrans()[sortAxis];
    float d2 = m2->GetTrans()[sortAxis];

    if( d1 < d2 )
        return -1;
    else if( d1 > d2 )
        return 1;

    return 0;
}


bool plClusterUtil::ISplitCluster(plSpanTemplateB* templ, plL2WTab& src, plL2WTab& lo, plL2WTab& hi)
{
    // Tried this, seems to work pretty well, but a more even grid is probably wiser at
    // this point.
#if 0 // MAX_SEP
    if( src.Count() <= fMinInsts)
        return false;

    // Pick an axis
    sortAxis = ISelectAxis(src);

    if( src.Count() < fMaxInsts)
    {
        Point3 len = ILength(src);
        if( len[sortAxis] < fMinSize )
            return false;
    }

    // Sort by that axis
    src.Sort(cmp);

    // Find the biggest gap
    float maxDist = 0;
    int pivot = 0;
    int i;
    for( i = 1; i < src.Count(); i++ )
    {
        float dist = src[i].GetTrans()[sortAxis] - src[i-1].GetTrans()[sortAxis];
        if( dist > maxDist )
        {
            maxDist = dist;
            pivot = i;
        }
    }
    hsAssert((pivot > 0) && (pivot < src.Count()), "Invalid pivot found");

    // Put everyone above it in hi, below it in lo
    lo.Append(pivot, src.Addr(0));
    hi.Append(src.Count()-pivot, src.Addr(pivot));

#else // MAX_SEP

    if( src.Count() <= fMinInsts )
        return false;

    // Pick an axis
    sortAxis = ISelectAxis(src);

    if( src.Count() < fMaxInsts)
    {
        Point3 len = ILength(src);
        if( len[sortAxis] < fMinSize )
            return false;
    }

    // Sort by that axis
    src.Sort(cmp);

    int pivot = src.Count() >> 1;
    lo.Append(pivot, src.Addr(0));
    hi.Append(src.Count()-pivot, src.Addr(pivot));
#endif // MAX_SEP

    return true;
}

void plClusterUtil::IFindClustersRecur(plSpanTemplateB* templ, plL2WTab& src, plL2WTabTab& dst)
{
    plL2WTab lo;
    plL2WTab hi;

    if( ISplitCluster(templ, src, lo, hi) )
    {
        // Keep going
        IFindClustersRecur(templ, lo, dst);
        IFindClustersRecur(templ, hi, dst);
    }
    else
    {
        plL2WTab* tab = new plL2WTab(src);
        dst.Append(1, &tab);
    }
}

void plClusterUtil::IFreeClustersRecur(plL2WTabTab& dst) const
{
    int i;
    for( i = 0; i < dst.Count(); i++ )
        delete dst[i];
}

inline float inlGetAlpha(uint32_t* color)
{
    return float(*color >> 24) / 255.99f;
}

plSpanEncoding plClusterUtil::ISelectEncoding(plPoint3TabTab& delPosTab, plColorTabTab& colorsTab)
{
    bool hasColor = false;
    bool hasAlpha = false;
    float maxLenSq = 0;
    float maxX = 0;
    float maxY = 0;
    float maxZ = 0;
    int i;
    for( i = 0; i < delPosTab.Count(); i++ )
    {
        int j;
        if( delPosTab[i] )
        {
            plPoint3Tab& delPos = *delPosTab[i];
            for( j = 0; j < delPos.Count(); j++ )
            {
                float lenSq = delPos[j].MagnitudeSquared();
                if( lenSq > maxLenSq )
                    maxLenSq = lenSq;
                float d = fabs(delPos[j].fX);
                if( d > maxX )
                    maxX = d;
                d = fabs(delPos[j].fY);
                if( d > maxY )
                    maxY = d;
                d = fabs(delPos[j].fZ);
                if( d > maxZ )
                    maxZ = d;

            }
        }

        if( colorsTab[i] )
        {
            plColorTab& color = *colorsTab[i];
            for( j = 0; j < color.Count(); j++ )
            {
                uint32_t col = color[j];
                if( (col & 0x00ffffff) != 0x00ffffff )
                    hasColor = true;
                if( (col & 0xff000000) != 0xff000000 )
                    hasAlpha = true;
            }
        }
    }

    uint32_t code = 0;
    float posScale = 1.f;

    if( hasColor && hasAlpha )
        code |= plSpanEncoding::kColAI88;
    else if( hasColor )
        code |= plSpanEncoding::kColI8;
    else if( hasAlpha )
        code |= plSpanEncoding::kColA8;

    plConst(float) kPosQuantum(0.5f / 12.f); // 1/2 inch.
    float maxLen = sqrt(maxLenSq);
    if( maxLen > kPosQuantum )
    {
        if( (maxX < kPosQuantum) && (maxY < kPosQuantum) )
        {
            code |= plSpanEncoding::kPos008;
            posScale = maxLen / 255.9f;
        }
        else if( (maxLen / 255.9f) < kPosQuantum )
        {
            code |= plSpanEncoding::kPos888;
            posScale = maxLen / 255.9f;
        }
        else if( (maxLen / float(1 << 10)) < kPosQuantum )
        {
            code |= plSpanEncoding::kPos101010;
            posScale = maxLen / float(1 << 10);
        }
        else
        {
            code |= plSpanEncoding::kPos161616;
            posScale = maxLen / float(1 << 16);
        }
    }
    return plSpanEncoding(code, posScale);
}

static int CompTemplates(const void *elem1, const void *elem2) 
{
    plSpanTemplateB* templA = *((plSpanTemplateB**)elem1);
    plSpanTemplateB* templB = *((plSpanTemplateB**)elem2);

    float hA = templA->GetLocalBounds().GetMaxs().fZ;
    float hB = templB->GetLocalBounds().GetMaxs().fZ;

    if( hA < hB )
        return -1;

    if( hA > hB )
        return 1;

    return 0;
}

void plClusterUtil::ISortTemplates(plSpanTemplTab& templs) const
{
    templs.Sort(CompTemplates);

    float maxZ = -1.e33f;

    int i;
    for( i = 1; i < templs.Count(); i++ )
    {
        templs[i]->fRenderLevel.Set(templs[i-1]->fRenderLevel.Level() + 1);
    }
}

plSpanTemplTab plClusterUtil::MakeTemplates(INode* templNode)
{
    plSpanTemplTab templs;
    IAddTemplates((plMaxNode*)templNode, templs);
    ISortTemplates(templs);
    return templs;
}

void plClusterUtil::AddClusters(plL2WTab& insts, plDeformVert* def, plShadeVert* shade)
{
    plPoint3TabTab delPos;
    plColorTabTab colors;

    plL2WTabTab clusters;
    IFindClustersRecur(fTemplate, insts, clusters);

    int j;
    for( j = 0; j < clusters.Count(); j++ )
    {
        // Create a plCluster to hold them all.
        plCluster* cluster = fGroup->IAddCluster();

        // Get the delPositions and colors for all the instances
        IAllocPosAndColor(fTemplate, *clusters[j], delPos, colors);

        IDelPosAndColor(fTemplate, 
                            *clusters[j],
                            def, shade,
                            delPos, colors);


        // Look through the results and pick out a proper encoding
        plSpanEncoding code = ISelectEncoding(delPos, colors);
        cluster->SetEncoding(code);

        // Now create, encode and add all the insts to the cluster.
        IAddInstsToCluster(cluster, fTemplate, *clusters[j], delPos, colors);

        IFreePosAndColor(delPos, colors);
    }
    
    IFreeClustersRecur(clusters);
}

void plClusterUtil::IAddInstsToCluster(plCluster* cluster, plSpanTemplateB* templ, 
                                       const plL2WTab& insts, 
                                       plPoint3TabTab& delPos, 
                                       plColorTabTab& colors)
{
    int i;
    for( i = 0; i < insts.Count(); i++ )
    {
        plSpanInstance* span = new plSpanInstance;
        span->Alloc(cluster->GetEncoding(), templ->NumVerts());

        span->SetLocalToWorld(plMaxNodeBase::Matrix3ToMatrix44(insts[i]));

        span->Encode(cluster->GetEncoding(), templ->NumVerts(),
            delPos[i] ? delPos[i]->Addr(0) : nullptr,
            colors[i] ? colors[i]->Addr(0) : nullptr);

        cluster->IAddInst(span);
    }
}


void plClusterUtil::IAllocPosAndColor(plSpanTemplateB* templ, const plL2WTab& insts,
                                    plPoint3TabTab& delPos, plColorTabTab& colors)
{
    delPos.SetCount(insts.Count());
    colors.SetCount(insts.Count());

    const int numVerts = templ->NumVerts();
    int i;
    for( i = 0; i < insts.Count(); i++ )
    {
        delPos[i] = nullptr;
        colors[i] = nullptr;
    }
}

void plClusterUtil::IFreePosAndColor(plPoint3TabTab& delPos, plColorTabTab& colors) const
{
    int i;
    for( i = 0; i < delPos.Count(); i++ )
        delete delPos[i];
    for( i = 0; i < colors.Count(); i++ )
        delete colors[i];
}

void plClusterUtil::IDelPosAndColor(plSpanTemplateB* templ, 
                                    const plL2WTab& insts, plDeformVert* def, plShadeVert* shade,
                                    plPoint3TabTab& delPos, plColorTabTab& colors)
{

    bool doDef = def != nullptr;
    bool doCol = shade != nullptr;
    // For each inst
    int i;
    for( i = 0; i < insts.Count(); i++ )
    {
        hsBounds3Ext wBnd = templ->GetLocalBounds();
        hsMatrix44 l2w = plMaxNodeBase::Matrix3ToMatrix44(insts[i]);
        hsMatrix44 w2l;
        l2w.GetInverse(&w2l);
        hsMatrix44 w2lT;
        w2l.GetTranspose(&w2lT);

        wBnd.Transform(&l2w);

        if( doDef )
        {
            def->Begin(templ->GetSrcNode(), wBnd);

            delPos[i] = new plPoint3Tab;
            delPos[i]->SetCount(templ->NumVerts());
            int j;
            for( j = 0; j < templ->NumVerts(); j++ )
            {
                hsPoint3 p = l2w * *templ->Position(j);
                plPoint3Tab& dp = *delPos[i];
                dp[j] = def->GetDel(p);
                dp[j] = w2l * dp[j];
            }
            
            def->End();
        }



        // Make the stored colors the actual output uint32_t.
        // templ has the mult and add colors, apply them here.
        if( doCol )
        {
            shade->Begin(templ->GetSrcNode(), wBnd);

            colors[i] = new plColorTab;
            colors[i]->SetCount(templ->NumVerts());
            int j;
            for( j = 0; j < templ->NumVerts(); j++ )
            {
                hsPoint3 pos = *templ->Position(j);
                pos += (*delPos[i])[j];
                pos = l2w * pos;

                hsVector3 norm = *templ->Normal(j);
                norm = w2lT * norm;
                
                Color rgb = shade->GetShade(pos, norm);

                rgb *= Color(templ->MultColor(j)->r, templ->MultColor(j)->g, templ->MultColor(j)->b);
                rgb += Color(templ->AddColor(j)->r, templ->AddColor(j)->g, templ->AddColor(j)->b);

                (*colors[i])[j] = hsColorRGBA().Set(rgb.r, rgb.g, rgb.b, templ->MultColor(j)->a).ToARGB32();
            }
            shade->End();
        }

    }
}

