/*==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 "MaxMain/MaxAPI.h"

#include "plRenderInstance.h"

class plNilView : public View 
{
    
public:
    
    Point2 ViewToScreen(Point3 p) { return Point2(p.x,p.y); }
    
    plNilView() 
    {       
        projType = 1;
        fov = hsConstants::pi<float> * 0.25f;
        pixelSize = 1.f;
        affineTM.IdentityMatrix();
        worldToView.IdentityMatrix();
        screenW=640.0f; screenH = 480.0f;
    }
    
};

static plNilView nilView;

plRenderInstance::plRenderInstance()
:   fNext(),
    fNode(),
    fObject(),
    fDeleteMesh()
{
    mtl = nullptr;
    mesh = nullptr;
    flags = 0;
    wireSize = 1.f;
    vis = 1.f;
    nodeID = 0;
    objMotBlurFrame = 0;
    objBlurID = 0;
    objToWorld.IdentityMatrix();
    objToCam.IdentityMatrix();
    normalObjToCam.IdentityMatrix();
    camToObj.IdentityMatrix();
    obBox.Init();
    center = Point3(0,0,0);
    radsq = 0;
}

plRenderInstance::~plRenderInstance()
{
}

void plRenderInstance::Cleanup()
{
    if( mesh && fDeleteMesh )
    {
        mesh->DeleteThis();
        mesh = nullptr;
        fDeleteMesh = false;
    }
}

BOOL plRenderInstance::Update(TimeValue& t)
{
    fObject = fNode->EvalWorldState(t).obj;
    if( !fObject )
        return false;

    // this shouldn't happen, we shouldn't be trying to make 
    // renderinstances from non GEOMOBJECT's
    if( fObject->SuperClassID() != GEOMOBJECT_CLASS_ID )
        return false;

    if( mesh && fDeleteMesh )
    {
        mesh->DeleteThis();
        mesh = nullptr;
    }
    fDeleteMesh = false;
    mesh = ((GeomObject*)fObject)->GetRenderMesh(t, fNode, nilView, fDeleteMesh);
    if( !mesh )
        return false;

    vis = fNode->GetVisibility(t);
    if( vis < 0.0f ) 
    {
        vis = 0.0f;
        SetFlag(INST_HIDE, 1);
        return false;
    }
    if (vis > 1.0f) vis = 1.0f;
    SetFlag(INST_HIDE, 0);

    objMotBlurFrame = NO_MOTBLUR;
    objBlurID = 0;

    objToWorld = fNode->GetObjectTM(t);
    objToCam = objToWorld;
    camToObj = Inverse(objToCam);

    normalObjToCam.IdentityMatrix();
    Matrix3 inv = camToObj;
    int i;
    for( i = 0; i < 3; i++ )
        normalObjToCam.SetRow(i, inv.GetColumn3(i));

    obBox = mesh->getBoundingBox(nullptr);
    center = obBox.Center();
    radsq = LengthSquared(obBox.Width());

    return true;
}

BOOL plRenderInstance::GetFromNode(INode* node, TimeValue& t, int idx)
{
    fNext = nullptr;

    fValid = Interval(t, t);

    fNode = node;
    mtl = node->GetMtl();
    if( mtl )
    {
        wireSize = mtl->WireSize();
    }

    nodeID = idx;

    ClearLights();

    return Update(t);
}

BOOL plRenderInstance::CastsShadowsFrom(const ObjLightDesc& constLt)
{
    ObjLightDesc& lt = const_cast<ObjLightDesc&>(constLt);
    if( !fNode->CastShadows() )
        return false;

    if( !lt.ls.shadow )
        return false;

    if( lt.GetExclList() && lt.GetExclList()->TestFlag(NT_AFFECT_SHADOWCAST) )
    {
        int idx = lt.GetExclList()->FindNode(fNode);
        BOOL isInc = lt.GetExclList()->TestFlag(NT_INCLUDE); 

        if( idx >= 0 )
        {
            return isInc;
        }
        else
        {
            return !isInc;
        }
    }

    return true;
}

Point3 plRenderInstance::GetFaceNormal(int fnum)
{
    Face* f = &mesh->faces[fnum];
    Point3 a = GetCamVert(f->v[1]) - GetCamVert(f->v[0]);
    Point3 b = GetCamVert(f->v[2]) - GetCamVert(f->v[0]);

    Point3 n = CrossProd(a, b).Normalize();
    return n;
}

Point3 plRenderInstance::GetFaceVertNormal(int fnum, int vertNum)
{
    Point3 retNorm;

    int smGroup=0;

    Face* f = &mesh->faces[fnum];

    // Get the rendered vertex.  Don't use the device position, fPos. 
    RVertex &rv = mesh->getRVert(f->v[vertNum]);

    // Number of normals at the vertex
    int numNormalsAtVert = (rv.rFlags & NORCT_MASK);

    // Specified normal ?
    int specNrml = (rv.rFlags & SPECIFIED_NORMAL);

    if (specNrml || (numNormalsAtVert == 1))
    {
        // The normal case is one normal per vertex (a vertex not beng shared by more than one smoothing group)
        // We'll assign vertex normals here.
        // If the object is faceted, this will be the same as the face normal.
        retNorm = rv.rn.getNormal();
    }
    else
    {
        int found = 0;
        for(int j=0;j<numNormalsAtVert; j++)
        {
            smGroup = rv.ern[j].getSmGroup();
            // Since this vertex is shared by more than one smoothing group, it has multiple normals.
            // This is fairly rare and doesn't occur in faceted objects.
            // Just pick the first normal and use that as the vertex normal.
            int faceSmGroup = f->getSmGroup();
            if ((smGroup & faceSmGroup) == faceSmGroup)
            {
                retNorm = rv.ern[j].getNormal();
                found++;

                // NOTE: Remove this to really check smoothing groups
                break;
            }
        }
    }
    retNorm = retNorm * normalObjToCam;
    retNorm.Normalize();
    return retNorm;
}

Point3 plRenderInstance::GetCamVert(int vertnum)
{
    return objToCam*mesh->verts[vertnum];
}

void plRenderInstance::GetObjVerts(int fnum, Point3 obp[3])
{
    Face* f = &mesh->faces[fnum];
    obp[0] = mesh->verts[f->v[0]];
    obp[1] = mesh->verts[f->v[1]];
    obp[2] = mesh->verts[f->v[2]];
}

void plRenderInstance::GetCamVerts(int fnum, Point3 cp[3])
{
    Face* f = &mesh->faces[fnum];
    cp[0] = objToCam*mesh->verts[f->v[0]];
    cp[1] = objToCam*mesh->verts[f->v[1]];
    cp[2] = objToCam*mesh->verts[f->v[2]];
}

Mtl* plRenderInstance::GetMtl(int fnum)
{
    if( !mtl )
        return nullptr;

    if( TestFlag(INST_MTL_BYFACE) )
    {
        if( mtl->ClassID() != Class_ID(MULTI_CLASS_ID,0) )
            return mtl;

        Face* f = &mesh->faces[fnum];
        int matIndex = f->getMatID();
        return mtl->GetSubMtl(matIndex);

    }
    else
    {
        return mtl;
    }
}

ULONG plRenderInstance::MtlRequirements(int mtlNum, int faceNum)
{
    if( !mtl )
        return 0;

    if( TestFlag(INST_MTL_BYFACE) )
    {
        Mtl* faceMtl = GetMtl(faceNum);
        return faceMtl ? faceMtl->Requirements(mtlNum) : 0;
    }
    return mtl->Requirements(mtlNum);
}