/*
---------------------------------------------------------------------------
Open Asset Import Library (ASSIMP)
---------------------------------------------------------------------------

Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

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with or without modification, are permitted provided that the following 
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* Redistributions of source code must retain the above
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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

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*/

/** @file Implementation of the 3ds importer class */


#include "AssimpPCH.h"

// internal headers
#include "3DSLoader.h"
#include "TargetAnimation.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Setup final material indices, generae a default material if necessary
void Discreet3DSImporter::ReplaceDefaultMaterial()
{
	// *******************************************************************
	// try to find an existing material that matches the
	// typical default material setting:
	// - no textures
	// - diffuse color (in grey!)
	// NOTE: This is here to workaround the fact that some
	// exporters are writing a default material, too.
	// *******************************************************************
	unsigned int idx = 0xcdcdcdcd;
	for (unsigned int i = 0; i < mScene->mMaterials.size();++i)
	{
		std::string s = mScene->mMaterials[i].mName;
		for (std::string::iterator it = s.begin(); it != s.end(); ++it)
			*it = ::tolower(*it);

		if (std::string::npos == s.find("default"))continue;

		if (mScene->mMaterials[i].mDiffuse.r !=
			mScene->mMaterials[i].mDiffuse.g ||
			mScene->mMaterials[i].mDiffuse.r !=
			mScene->mMaterials[i].mDiffuse.b)continue;

		if (mScene->mMaterials[i].sTexDiffuse.mMapName.length()   != 0	||
			mScene->mMaterials[i].sTexBump.mMapName.length()      != 0	|| 
			mScene->mMaterials[i].sTexOpacity.mMapName.length()   != 0	||
			mScene->mMaterials[i].sTexEmissive.mMapName.length()  != 0	||
			mScene->mMaterials[i].sTexSpecular.mMapName.length()  != 0	||
			mScene->mMaterials[i].sTexShininess.mMapName.length() != 0 )
		{
			continue;
		}
		idx = i;
	}
	if (0xcdcdcdcd == idx)idx = (unsigned int)mScene->mMaterials.size();

	// now iterate through all meshes and through all faces and
	// find all faces that are using the default material
	unsigned int cnt = 0;
	for (std::vector<D3DS::Mesh>::iterator
		i =  mScene->mMeshes.begin();
		i != mScene->mMeshes.end();++i)
	{
		for (std::vector<unsigned int>::iterator
			a =  (*i).mFaceMaterials.begin();
			a != (*i).mFaceMaterials.end();++a)
		{
			// NOTE: The additional check seems to be necessary,
			// some exporters seem to generate invalid data here
			if (0xcdcdcdcd == (*a))
			{
				(*a) = idx;
				++cnt;
			}
			else if ( (*a) >= mScene->mMaterials.size())
			{
				(*a) = idx;
				DefaultLogger::get()->warn("Material index overflow in 3DS file. Using default material");
				++cnt;
			}
		}
	}
	if (cnt && idx == mScene->mMaterials.size())
	{
		// We need to create our own default material
		D3DS::Material sMat;
		sMat.mDiffuse = aiColor3D(0.3f,0.3f,0.3f);
		sMat.mName = "%%%DEFAULT";
		mScene->mMaterials.push_back(sMat);

		DefaultLogger::get()->info("3DS: Generating default material");
	}
	return;
}

// ------------------------------------------------------------------------------------------------
// Check whether all indices are valid. Otherwise we'd crash before the validation step was reached
void Discreet3DSImporter::CheckIndices(D3DS::Mesh& sMesh)
{
	for (std::vector< D3DS::Face >::iterator
		 i =  sMesh.mFaces.begin();
		 i != sMesh.mFaces.end();++i)
	{
		// check whether all indices are in range
		for (unsigned int a = 0; a < 3;++a)
		{
			if ((*i).mIndices[a] >= sMesh.mPositions.size())
			{
				DefaultLogger::get()->warn("3DS: Vertex index overflow)");
				(*i).mIndices[a] = (uint32_t)sMesh.mPositions.size()-1;
			}
			if ( !sMesh.mTexCoords.empty() && (*i).mIndices[a] >= sMesh.mTexCoords.size())
			{
				DefaultLogger::get()->warn("3DS: Texture coordinate index overflow)");
				(*i).mIndices[a] = (uint32_t)sMesh.mTexCoords.size()-1;
			}
		}
	}
	return;
}

// ------------------------------------------------------------------------------------------------
// Generate out unique verbose format representation
void Discreet3DSImporter::MakeUnique(D3DS::Mesh& sMesh)
{
	// Allocate output storage
	std::vector<aiVector3D> vNew  (sMesh.mFaces.size() * 3);
	std::vector<aiVector3D> vNew2;
	if (sMesh.mTexCoords.size())
		vNew2.resize(sMesh.mFaces.size() * 3);

	for (unsigned int i = 0, base = 0; i < sMesh.mFaces.size();++i)
	{
		D3DS::Face& face = sMesh.mFaces[i];

		// Positions
		for (unsigned int a = 0; a < 3;++a,++base)
		{
			vNew[base] = sMesh.mPositions[face.mIndices[a]];
			if (sMesh.mTexCoords.size())
				vNew2[base] = sMesh.mTexCoords[face.mIndices[a]];

			face.mIndices[a] = base;
		}
	}
	sMesh.mPositions = vNew;
	sMesh.mTexCoords = vNew2;
	return;
}

// ------------------------------------------------------------------------------------------------
void CopyTexture(MaterialHelper& mat, D3DS::Texture& texture, aiTextureType type)
{
	// Setup the texture name
	aiString tex;
	tex.Set( texture.mMapName);
	mat.AddProperty( &tex, AI_MATKEY_TEXTURE(type,0));

	// Setup the texture blend factor
	if (is_not_qnan(texture.mTextureBlend))
		mat.AddProperty<float>( &texture.mTextureBlend, 1, AI_MATKEY_TEXBLEND(type,0));

	// Setup the texture mapping mode
	mat.AddProperty<int>((int*)&texture.mMapMode,1,AI_MATKEY_MAPPINGMODE_U(type,0));
	mat.AddProperty<int>((int*)&texture.mMapMode,1,AI_MATKEY_MAPPINGMODE_V(type,0));

	// Mirroring - double the scaling values 
	if (texture.mMapMode == aiTextureMapMode_Mirror)
	{
		texture.mScaleU *= 2.f;
		texture.mScaleV *= 2.f;
		texture.mOffsetU /= 2.f;
		texture.mOffsetV /= 2.f;
	}
	
	// Setup texture UV transformations
	mat.AddProperty<float>(&texture.mOffsetU,5,AI_MATKEY_UVTRANSFORM(type,0));
}

// ------------------------------------------------------------------------------------------------
// Convert a 3DS material to an aiMaterial
void Discreet3DSImporter::ConvertMaterial(D3DS::Material& oldMat,
	MaterialHelper& mat)
{
	// NOTE: Pass the background image to the viewer by bypassing the
	// material system. This is an evil hack, never do it again!
	if (0 != mBackgroundImage.length() && bHasBG)
	{
		aiString tex;
		tex.Set( mBackgroundImage);
		mat.AddProperty( &tex, AI_MATKEY_GLOBAL_BACKGROUND_IMAGE);

		// Be sure this is only done for the first material
		mBackgroundImage = std::string("");
	}

	// At first add the base ambient color of the scene to the material
	oldMat.mAmbient.r += mClrAmbient.r;
	oldMat.mAmbient.g += mClrAmbient.g;
	oldMat.mAmbient.b += mClrAmbient.b;

	aiString name;
	name.Set( oldMat.mName);
	mat.AddProperty( &name, AI_MATKEY_NAME);

	// Material colors
	mat.AddProperty( &oldMat.mAmbient, 1, AI_MATKEY_COLOR_AMBIENT);
	mat.AddProperty( &oldMat.mDiffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
	mat.AddProperty( &oldMat.mSpecular, 1, AI_MATKEY_COLOR_SPECULAR);
	mat.AddProperty( &oldMat.mEmissive, 1, AI_MATKEY_COLOR_EMISSIVE);

	// Phong shininess and shininess strength
	if (D3DS::Discreet3DS::Phong == oldMat.mShading || 
		D3DS::Discreet3DS::Metal == oldMat.mShading)
	{
		if (!oldMat.mSpecularExponent || !oldMat.mShininessStrength)
		{
			oldMat.mShading = D3DS::Discreet3DS::Gouraud;
		}
		else
		{
			mat.AddProperty( &oldMat.mSpecularExponent, 1, AI_MATKEY_SHININESS);
			mat.AddProperty( &oldMat.mShininessStrength, 1, AI_MATKEY_SHININESS_STRENGTH);
		}
	}

	// Opacity
	mat.AddProperty<float>( &oldMat.mTransparency,1,AI_MATKEY_OPACITY);

	// Bump height scaling
	mat.AddProperty<float>( &oldMat.mBumpHeight,1,AI_MATKEY_BUMPSCALING);

	// Two sided rendering?
	if (oldMat.mTwoSided)
	{
		int i = 1;
		mat.AddProperty<int>(&i,1,AI_MATKEY_TWOSIDED);
	}

	// Shading mode
	aiShadingMode eShading = aiShadingMode_NoShading;
	switch (oldMat.mShading)
	{
		case D3DS::Discreet3DS::Flat:
			eShading = aiShadingMode_Flat; break;

		// I don't know what "Wire" shading should be,
		// assume it is simple lambertian diffuse shading
		case D3DS::Discreet3DS::Wire:
			{
				// Set the wireframe flag
				unsigned int iWire = 1;
				mat.AddProperty<int>( (int*)&iWire,1,AI_MATKEY_ENABLE_WIREFRAME);
			}

		case D3DS::Discreet3DS::Gouraud:
			eShading = aiShadingMode_Gouraud; break;

		// assume cook-torrance shading for metals.
		case D3DS::Discreet3DS::Phong :
			eShading = aiShadingMode_Phong; break;

		case D3DS::Discreet3DS::Metal :
			eShading = aiShadingMode_CookTorrance; break;

			// FIX to workaround a warning with GCC 4 who complained
			// about a missing case Blinn: here - Blinn isn't a valid
			// value in the 3DS Loader, it is just needed for ASE
		case D3DS::Discreet3DS::Blinn :
			eShading = aiShadingMode_Blinn; break;
	}
	mat.AddProperty<int>( (int*)&eShading,1,AI_MATKEY_SHADING_MODEL);

	// DIFFUSE texture
	if( oldMat.sTexDiffuse.mMapName.length() > 0)
		CopyTexture(mat,oldMat.sTexDiffuse, aiTextureType_DIFFUSE);

	// SPECULAR texture
	if( oldMat.sTexSpecular.mMapName.length() > 0)
		CopyTexture(mat,oldMat.sTexSpecular, aiTextureType_SPECULAR);

	// OPACITY texture
	if( oldMat.sTexOpacity.mMapName.length() > 0)
		CopyTexture(mat,oldMat.sTexOpacity, aiTextureType_OPACITY);

	// EMISSIVE texture
	if( oldMat.sTexEmissive.mMapName.length() > 0)
		CopyTexture(mat,oldMat.sTexEmissive, aiTextureType_EMISSIVE);

	// BUMP texture
	if( oldMat.sTexBump.mMapName.length() > 0)
		CopyTexture(mat,oldMat.sTexBump, aiTextureType_HEIGHT);

	// SHININESS texture
	if( oldMat.sTexShininess.mMapName.length() > 0)
		CopyTexture(mat,oldMat.sTexShininess, aiTextureType_SHININESS);

	// Store the name of the material itself, too
	if( oldMat.mName.length())
	{
		aiString tex;
		tex.Set( oldMat.mName);
		mat.AddProperty( &tex, AI_MATKEY_NAME);
	}
	return;
}

// ------------------------------------------------------------------------------------------------
// Split meshes by their materials and generate output aiMesh'es
void Discreet3DSImporter::ConvertMeshes(aiScene* pcOut)
{
	std::vector<aiMesh*> avOutMeshes;
	avOutMeshes.reserve(mScene->mMeshes.size() * 2);

	unsigned int iFaceCnt = 0;

	// we need to split all meshes by their materials
	for (std::vector<D3DS::Mesh>::iterator i =  mScene->mMeshes.begin();
		i != mScene->mMeshes.end();++i)
	{
		std::vector<unsigned int>* aiSplit = new std::vector<unsigned int>[
			mScene->mMaterials.size()];

		unsigned int iNum = 0;
		for (std::vector<unsigned int>::const_iterator a =  (*i).mFaceMaterials.begin();
			a != (*i).mFaceMaterials.end();++a,++iNum)
		{
			aiSplit[*a].push_back(iNum);
		}
		// now generate submeshes
		for (unsigned int p = 0; p < mScene->mMaterials.size();++p)
		{
			if (aiSplit[p].size())
			{
				aiMesh* meshOut = new aiMesh();
				meshOut->mPrimitiveTypes = aiPrimitiveType_TRIANGLE;

				// be sure to setup the correct material index
				meshOut->mMaterialIndex = p;

				// use the color data as temporary storage
				meshOut->mColors[0] = (aiColor4D*)(&*i);
				avOutMeshes.push_back(meshOut);
				
				// convert vertices
				meshOut->mNumFaces = (unsigned int)aiSplit[p].size();
				meshOut->mNumVertices = meshOut->mNumFaces*3;

				// allocate enough storage for faces
				meshOut->mFaces = new aiFace[meshOut->mNumFaces];
				iFaceCnt += meshOut->mNumFaces;
			
				meshOut->mVertices = new aiVector3D[meshOut->mNumVertices];
				meshOut->mNormals  = new aiVector3D[meshOut->mNumVertices];
				if ((*i).mTexCoords.size())
				{
					meshOut->mTextureCoords[0] = new aiVector3D[meshOut->mNumVertices];
				}
				for (unsigned int q = 0, base = 0; q < aiSplit[p].size();++q)
				{
					register unsigned int index = aiSplit[p][q];
					aiFace& face = meshOut->mFaces[q];

					face.mIndices = new unsigned int[3];
					face.mNumIndices = 3;

					for (unsigned int a = 0; a < 3;++a,++base)
					{
						unsigned int idx = (*i).mFaces[index].mIndices[a];
						meshOut->mVertices[base]  = (*i).mPositions[idx];
						meshOut->mNormals [base]  = (*i).mNormals[idx];

						if ((*i).mTexCoords.size())
							meshOut->mTextureCoords[0][base] = (*i).mTexCoords[idx];

						face.mIndices[a] = base;
					}
				}
			}
		}
		delete[] aiSplit;
	}

	// Copy them to the output array
	pcOut->mNumMeshes = (unsigned int)avOutMeshes.size();
	pcOut->mMeshes = new aiMesh*[pcOut->mNumMeshes]();
	for (unsigned int a = 0; a < pcOut->mNumMeshes;++a)
		pcOut->mMeshes[a] = avOutMeshes[a];

	// We should have at least one face here
	if (!iFaceCnt)
		throw new ImportErrorException("No faces loaded. The mesh is empty");
}

// ------------------------------------------------------------------------------------------------
// Add a node to the scenegraph and setup its final transformation
void Discreet3DSImporter::AddNodeToGraph(aiScene* pcSOut,aiNode* pcOut,
	D3DS::Node* pcIn, aiMatrix4x4& absTrafo)
{
	std::vector<unsigned int> iArray;
	iArray.reserve(3);

	aiMatrix4x4 abs;
	if (pcIn->mName == "$$$DUMMY")
	{
		// FIX: Append the "real" name of the dummy to the string
		pcIn->mName = "Dummy." + pcIn->mDummyName;
	}
	else // if (pcIn->mName != "$$$DUMMY")
	{		
		// Find all meshes with the same name as the node
		for (unsigned int a = 0; a < pcSOut->mNumMeshes;++a)
		{
			const D3DS::Mesh* pcMesh = (const D3DS::Mesh*)pcSOut->mMeshes[a]->mColors[0];
			ai_assert(NULL != pcMesh);

			if (pcIn->mName == pcMesh->mName)
				iArray.push_back(a);
		}
		if (!iArray.empty())
		{
			// The matrix should be identical for all meshes with the 
			// same name. It HAS to be identical for all meshes .....
			aiMatrix4x4 mInv = ((D3DS::Mesh*)pcSOut->mMeshes[iArray[0]]->mColors[0])->mMat;
			mInv.Inverse();
			const aiVector3D& pivot = pcIn->vPivot;

			pcOut->mNumMeshes = (unsigned int)iArray.size();
			pcOut->mMeshes = new unsigned int[iArray.size()];
			for (unsigned int i = 0;i < iArray.size();++i)
			{
				const unsigned int iIndex = iArray[i];
				aiMesh* const mesh = pcSOut->mMeshes[iIndex];

				// Pivot point adjustment
				// See: http://www.zfx.info/DisplayThread.php?MID=235690#235690
				const aiVector3D* const pvEnd = mesh->mVertices+mesh->mNumVertices;
				aiVector3D* pvCurrent = mesh->mVertices;

				if(pivot.x || pivot.y || pivot.z)
				{
					for (;pvCurrent != pvEnd;++pvCurrent)
					{
						*pvCurrent = mInv * (*pvCurrent);
						*pvCurrent -= pivot;
					}
				}
				else
				{
					for (;pvCurrent != pvEnd;++pvCurrent)
						*pvCurrent = mInv * (*pvCurrent);
				}
				// Setup the mesh index
				pcOut->mMeshes[i] = iIndex;
			}
		}
	}

	// Now build the transformation matrix of the node
	// ROTATION
	if (pcIn->aRotationKeys.size())
	{
		pcOut->mTransformation = aiMatrix4x4( pcIn->aRotationKeys[0].mValue.GetMatrix() );
	}
	else if (pcIn->aCameraRollKeys.size())
	{
		aiMatrix4x4::RotationZ(AI_DEG_TO_RAD(- pcIn->aCameraRollKeys[0].mValue),
			pcOut->mTransformation);
	}

	// SCALING
	aiMatrix4x4& m = pcOut->mTransformation;
	if (pcIn->aScalingKeys.size())
	{
		const aiVector3D& v = pcIn->aScalingKeys[0].mValue;
		m.a1 *= v.x; m.b1 *= v.x; m.c1 *= v.x;
		m.a2 *= v.y; m.b2 *= v.y; m.c2 *= v.y;
		m.a3 *= v.z; m.b3 *= v.z; m.c3 *= v.z;
	}

	// TRANSLATION
	if (pcIn->aPositionKeys.size())
	{
		const aiVector3D& v = pcIn->aPositionKeys[0].mValue;
		m.a4 += v.x;
		m.b4 += v.y;
		m.c4 += v.z;
	}

	// Generate animation channels for the node
	if (pcIn->aPositionKeys.size()  > 1  || pcIn->aRotationKeys.size()   > 1   ||
		pcIn->aScalingKeys.size()   > 1  || pcIn->aCameraRollKeys.size() > 1 ||
		pcIn->aTargetPositionKeys.size() > 1)
	{
		aiAnimation* anim = pcSOut->mAnimations[0];
		ai_assert(NULL != anim);

		if (pcIn->aCameraRollKeys.size() > 1)
		{
			DefaultLogger::get()->debug("3DS: Converting camera roll track ...");

			// Camera roll keys - in fact they're just rotations
			// around the camera's z axis. The angles are given
			// in degrees (and they're clockwise).
			pcIn->aRotationKeys.resize(pcIn->aCameraRollKeys.size());
			for (unsigned int i = 0; i < pcIn->aCameraRollKeys.size();++i)
			{
				aiQuatKey&  q = pcIn->aRotationKeys[i];
				aiFloatKey& f = pcIn->aCameraRollKeys[i];

				q.mTime  = f.mTime;
				q.mValue = aiQuaternion(0.f,0.f,AI_DEG_TO_RAD(- f.mValue));
			}
		}

		if (pcIn->aTargetPositionKeys.size() > 1)
		{
			DefaultLogger::get()->debug("3DS: Converting target track ...");

			// Camera or spot light - need to convert the separate
			// target position channel to our representation
			TargetAnimationHelper helper;

			if (pcIn->aPositionKeys.empty())
			{
				// We can just pass zero here ...
				helper.SetFixedMainAnimationChannel(aiVector3D());
			}
			else  helper.SetMainAnimationChannel(&pcIn->aPositionKeys);
			helper.SetTargetAnimationChannel(&pcIn->aTargetPositionKeys);

			// Do the conversion
			std::vector<aiVectorKey> distanceTrack;
			helper.Process(&distanceTrack);

			// Now add a new node as child, name it <ourName>.Target
			// and assign the distance track to it. This is that the
			// information where the target is and how it moves is
			// not lost
			D3DS::Node* nd = new D3DS::Node();
			pcIn->push_back(nd);

			nd->mName = pcIn->mName + ".Target";

			aiNodeAnim* nda = anim->mChannels[anim->mNumChannels++] = new aiNodeAnim();
			nda->mNodeName.Set(nd->mName);

			nda->mNumPositionKeys = (unsigned int)distanceTrack.size();
			nda->mPositionKeys = new aiVectorKey[nda->mNumPositionKeys];
			::memcpy(nda->mPositionKeys,&distanceTrack[0],
				sizeof(aiVectorKey)*nda->mNumPositionKeys);
		}

		// Allocate a new nda, increment the nda index
		aiNodeAnim* nda = anim->mChannels[anim->mNumChannels++] = new aiNodeAnim();
		nda->mNodeName.Set(pcIn->mName);

		// POSITION keys
		if (pcIn->aPositionKeys.size()  > 0)
		{
			nda->mNumPositionKeys = (unsigned int)pcIn->aPositionKeys.size();
			nda->mPositionKeys = new aiVectorKey[nda->mNumPositionKeys];
			::memcpy(nda->mPositionKeys,&pcIn->aPositionKeys[0],
				sizeof(aiVectorKey)*nda->mNumPositionKeys);
		}

		// ROTATION keys
		if (pcIn->aRotationKeys.size()  > 0)
		{
			nda->mNumRotationKeys = (unsigned int)pcIn->aRotationKeys.size();
			nda->mRotationKeys = new aiQuatKey[nda->mNumRotationKeys];

			// Rotations are quaternion offsets
			aiQuaternion abs;
			for (unsigned int n = 0; n < nda->mNumRotationKeys;++n)
			{
				const aiQuatKey& q = pcIn->aRotationKeys[n];

				abs = (n ? abs * q.mValue : q.mValue);
				nda->mRotationKeys[n].mTime  = q.mTime;
				nda->mRotationKeys[n].mValue = abs.Normalize();
			}
		}

		// SCALING keys
		if (pcIn->aScalingKeys.size()  > 0)
		{
			nda->mNumScalingKeys = (unsigned int)pcIn->aScalingKeys.size();
			nda->mScalingKeys = new aiVectorKey[nda->mNumScalingKeys];
			::memcpy(nda->mScalingKeys,&pcIn->aScalingKeys[0],
				sizeof(aiVectorKey)*nda->mNumScalingKeys);
		}
	}

	// Setup the name of the node
	pcOut->mName.Set(pcIn->mName);

	// Allocate storage for children 
	pcOut->mNumChildren = (unsigned int)pcIn->mChildren.size();
	pcOut->mChildren = new aiNode*[pcIn->mChildren.size()];

	// Recursively process all children
	const unsigned int size = pcIn->mChildren.size();
	for (unsigned int i = 0; i < size;++i)
	{
		pcOut->mChildren[i] = new aiNode();
		pcOut->mChildren[i]->mParent = pcOut;
		AddNodeToGraph(pcSOut,pcOut->mChildren[i],pcIn->mChildren[i],abs);
	}
	return;
}

// ------------------------------------------------------------------------------------------------
// Find out how many node animation channels we'll have finally
void CountTracks(D3DS::Node* node, unsigned int& cnt)
{
	// We will never generate more than one channel for a node, so
	// this is rather easy here.

	if (node->aPositionKeys.size()  > 1  || node->aRotationKeys.size()   > 1   ||
		node->aScalingKeys.size()   > 1  || node->aCameraRollKeys.size() > 1 ||
		node->aTargetPositionKeys.size()  > 1)
	{
		++cnt;

		if (node->aTargetPositionKeys.size()  > 1)++cnt;
	}

	// Recursively process all children
	for (unsigned int i = 0; i < node->mChildren.size();++i)
		CountTracks(node->mChildren[i],cnt);
}

// ------------------------------------------------------------------------------------------------
// Generate the output node graph
void Discreet3DSImporter::GenerateNodeGraph(aiScene* pcOut)
{
	pcOut->mRootNode = new aiNode();

	if (0 == mRootNode->mChildren.size())
	{
		// seems the file has not even a hierarchy.
		// generate a flat hiearachy which looks like this:
		//
		//                ROOT_NODE
		//                   |
		//   ----------------------------------------
		//   |       |       |            |         |  
		// MESH_0  MESH_1  MESH_2  ...  MESH_N    CAMERA_0 ....
		//
		DefaultLogger::get()->warn("No hierarchy information has been found in the file. ");

		pcOut->mRootNode->mNumChildren = pcOut->mNumMeshes + 
			mScene->mCameras.size() + mScene->mLights.size();

		pcOut->mRootNode->mChildren = new aiNode* [ pcOut->mRootNode->mNumChildren ];
		pcOut->mRootNode->mName.Set("<3DSDummyRoot>");

		// Build dummy nodes for all meshes
		unsigned int a = 0;
		for (unsigned int i = 0; i < pcOut->mNumMeshes;++i,++a)
		{
			aiNode* pcNode = pcOut->mRootNode->mChildren[a] = new aiNode();
			pcNode->mParent = pcOut->mRootNode;
			pcNode->mMeshes = new unsigned int[1];
			pcNode->mMeshes[0] = i;
			pcNode->mNumMeshes = 1;

			// Build a name for the node
			pcNode->mName.length = sprintf(pcNode->mName.data,"3DSMesh_%i",i);	
		}

		// Build dummy nodes for all cameras
		for (unsigned int i = 0; i < (unsigned int )mScene->mCameras.size();++i,++a)
		{
			aiNode* pcNode = pcOut->mRootNode->mChildren[a] = new aiNode();
			pcNode->mParent = pcOut->mRootNode;

			// Build a name for the node
			pcNode->mName = mScene->mCameras[i]->mName;
		}

		// Build dummy nodes for all lights
		for (unsigned int i = 0; i < (unsigned int )mScene->mLights.size();++i,++a)
		{
			aiNode* pcNode = pcOut->mRootNode->mChildren[a] = new aiNode();
			pcNode->mParent = pcOut->mRootNode;

			// Build a name for the node
			pcNode->mName = mScene->mLights[i]->mName;
		}
	}
	else
	{
		// First of all: find out how many scaling, rotation and translation
		// animation tracks we'll have afterwards
		unsigned int numChannel = 0;
		CountTracks(mRootNode,numChannel);

		if (numChannel)
		{
			// Allocate a primary animation channel
			pcOut->mNumAnimations = 1;
			pcOut->mAnimations    = new aiAnimation*[1];
			aiAnimation* anim     = pcOut->mAnimations[0] = new aiAnimation();

			anim->mName.Set("3DSMasterAnim");

			// Allocate enough storage for all node animation channels, 
			// but don't set the mNumChannels member - we'll use it to
			// index into the array
			anim->mChannels = new aiNodeAnim*[numChannel];
		}

		aiMatrix4x4 m;
		AddNodeToGraph(pcOut,  pcOut->mRootNode, mRootNode,m);

		// If the root node is unnamed name it "<3DSRoot>"
		if (::strstr( pcOut->mRootNode->mName.data, "UNNAMED" )
			|| pcOut->mRootNode->mName.data[0] == '$' 
			&& pcOut->mRootNode->mName.data[1] == '$')
		{
			pcOut->mRootNode->mName.Set("<3DSRoot>");
		}
	}

	// We used the first vertex color set to store some
	// temporary values, so we need to cleanup here
	for (unsigned int a = 0; a < pcOut->mNumMeshes;++a)
		pcOut->mMeshes[a]->mColors[0] = NULL;

	// if the root node has only one child ... set the child as root node
	if (1 == pcOut->mRootNode->mNumChildren)
	{
		aiNode* pcOld = pcOut->mRootNode;
		pcOut->mRootNode = pcOut->mRootNode->mChildren[0];
		pcOut->mRootNode->mParent = NULL;
		pcOld->mChildren[0] = NULL;
		delete pcOld;
	}
}

// ------------------------------------------------------------------------------------------------
// Convert all meshes in the scene and generate the final output scene.
void Discreet3DSImporter::ConvertScene(aiScene* pcOut)
{
	// Allocate enough storage for all output materials
	pcOut->mNumMaterials = (unsigned int)mScene->mMaterials.size();
	pcOut->mMaterials    = new aiMaterial*[pcOut->mNumMaterials];

	//  ... and convert the 3DS materials to aiMaterial's
	for (unsigned int i = 0; i < pcOut->mNumMaterials;++i)
	{
		MaterialHelper* pcNew = new MaterialHelper();
		ConvertMaterial(mScene->mMaterials[i],*pcNew);
		pcOut->mMaterials[i] = pcNew;
	}

	// Generate the output mesh list
	ConvertMeshes(pcOut);

	// Now copy all light sources to the output scene
	pcOut->mNumLights = (unsigned int)mScene->mLights.size();
	if (pcOut->mNumLights)
	{
		pcOut->mLights = new aiLight*[pcOut->mNumLights];
		::memcpy(pcOut->mLights,&mScene->mLights[0],sizeof(void*)*pcOut->mNumLights);
	}

	// Now copy all cameras to the output scene
	pcOut->mNumCameras = (unsigned int)mScene->mCameras.size();
	if (pcOut->mNumCameras)
	{
		pcOut->mCameras = new aiCamera*[pcOut->mNumCameras];
		::memcpy(pcOut->mCameras,&mScene->mCameras[0],sizeof(void*)*pcOut->mNumCameras);
	}

	return;
}
