/*
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Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

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*/

/** @file Implementation of the Collada loader */

#include "AssimpPCH.h"
#ifndef ASSIMP_BUILD_NO_DAE_IMPORTER

#include "../include/aiAnim.h"
#include "ColladaLoader.h"
#include "ColladaParser.h"

#include "fast_atof.h"
#include "ParsingUtils.h"

#include "time.h"

using namespace Assimp;

// ------------------------------------------------------------------------------------------------
// Constructor to be privately used by Importer
ColladaLoader::ColladaLoader()
{}

// ------------------------------------------------------------------------------------------------
// Destructor, private as well
ColladaLoader::~ColladaLoader()
{}

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool ColladaLoader::CanRead( const std::string& pFile, IOSystem* pIOHandler, bool checkSig) const
{
	// check file extension 
	std::string extension = GetExtension(pFile);
	
	if( extension == "dae")
		return true;

	// XML - too generic, we need to open the file and search for typical keywords
	if( extension == "xml" || !extension.length() || checkSig)	{
		/*  If CanRead() is called in order to check whether we
		 *  support a specific file extension in general pIOHandler
		 *  might be NULL and it's our duty to return true here.
		 */
		if (!pIOHandler)return true;
		const char* tokens[] = {"collada"};
		return SearchFileHeaderForToken(pIOHandler,pFile,tokens,1);
	}
	return false;
}

// ------------------------------------------------------------------------------------------------
// Get file extension list
void ColladaLoader::GetExtensionList( std::string& append)
{
	append.append("*.dae");
}

// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void ColladaLoader::InternReadFile( const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler)
{
	mFileName = pFile;

	// clean all member arrays - just for safety, it should work even if we did not
	mMeshIndexByID.clear();
	mMaterialIndexByName.clear();
	mMeshes.clear();
	newMats.clear();
	mLights.clear();
	mCameras.clear();
	mTextures.clear();

	// parse the input file
	ColladaParser parser( pIOHandler, pFile);

	if( !parser.mRootNode)
		throw new ImportErrorException( "Collada: File came out empty. Something is wrong here.");

	// reserve some storage to avoid unnecessary reallocs
	newMats.reserve(parser.mMaterialLibrary.size()*2);
	mMeshes.reserve(parser.mMeshLibrary.size()*2);

	mCameras.reserve(parser.mCameraLibrary.size());
	mLights.reserve(parser.mLightLibrary.size());

	// create the materials first, for the meshes to find
	BuildMaterials( parser, pScene);

	// build the node hierarchy from it
	pScene->mRootNode = BuildHierarchy( parser, parser.mRootNode);

	// ... then fill the materials with the now adjusted settings
	FillMaterials(parser, pScene);

	// Convert to Y_UP, if different orientation
	if( parser.mUpDirection == ColladaParser::UP_X)
		pScene->mRootNode->mTransformation *= aiMatrix4x4( 
			 0, -1,  0,  0, 
			 1,  0,  0,  0,
			 0,  0,  1,  0,
			 0,  0,  0,  1);
	else if( parser.mUpDirection == ColladaParser::UP_Z)
		pScene->mRootNode->mTransformation *= aiMatrix4x4( 
			 1,  0,  0,  0, 
			 0,  0,  1,  0,
			 0, -1,  0,  0,
			 0,  0,  0,  1);

	// store all meshes
	StoreSceneMeshes( pScene);

	// store all materials
	StoreSceneMaterials( pScene);

	// store all lights
	StoreSceneLights( pScene);

	// store all cameras
	StoreSceneCameras( pScene);
}

// ------------------------------------------------------------------------------------------------
// Recursively constructs a scene node for the given parser node and returns it.
aiNode* ColladaLoader::BuildHierarchy( const ColladaParser& pParser, const Collada::Node* pNode)
{
	// create a node for it
	aiNode* node = new aiNode();

	// now setup the name of the node. We take the name if not empty, otherwise the collada ID
	// FIX: Workaround for XSI calling the instanced visual scene 'untitled' by default.
	if (!pNode->mName.empty() && pNode->mName != "untitled")
		node->mName.Set(pNode->mName);
	else if (!pNode->mID.empty())
		node->mName.Set(pNode->mID);
	else
	{
		// No need to worry. Unnamed nodes are no problem at all, except
		// if cameras or lights need to be assigned to them.
		if (!pNode->mLights.empty() || !pNode->mCameras.empty()) {
	
			::strcpy(node->mName.data,"$ColladaAutoName$_");
			node->mName.length = 17 + ASSIMP_itoa10(node->mName.data+18,MAXLEN-18,(uint32_t)clock());
		}
	}
	
	// calculate the transformation matrix for it
	node->mTransformation = pParser.CalculateResultTransform( pNode->mTransforms);

	// now resolve node instances
	std::vector<Collada::Node*> instances;
	ResolveNodeInstances(pParser,pNode,instances);

	// add children. first the *real* ones
	node->mNumChildren = pNode->mChildren.size()+instances.size();
	node->mChildren = new aiNode*[node->mNumChildren];

	unsigned int a = 0;
	for(; a < pNode->mChildren.size(); a++)
	{
		node->mChildren[a] = BuildHierarchy( pParser, pNode->mChildren[a]);
		node->mChildren[a]->mParent = node;
	}

	// ... and finally the resolved node instances
	for(; a < node->mNumChildren; a++)
	{
		node->mChildren[a] = BuildHierarchy( pParser, instances[a-pNode->mChildren.size()]);
		node->mChildren[a]->mParent = node;
	}

	// construct meshes
	BuildMeshesForNode( pParser, pNode, node);

	// construct cameras
	BuildCamerasForNode(pParser, pNode, node);

	// construct lights
	BuildLightsForNode(pParser, pNode, node);
	return node;
}

// ------------------------------------------------------------------------------------------------
// Resolve node instances
void ColladaLoader::ResolveNodeInstances( const ColladaParser& pParser, const Collada::Node* pNode,
	std::vector<Collada::Node*>& resolved)
{
	// reserve enough storage
	resolved.reserve(pNode->mNodeInstances.size());

	// ... and iterate through all nodes to be instanced as children of pNode
	for (std::vector<Collada::NodeInstance>::const_iterator it = pNode->mNodeInstances.begin(),
		 end = pNode->mNodeInstances.end(); it != end; ++it)
	{
		// find the corresponding node in the library
		ColladaParser::NodeLibrary::const_iterator fnd = pParser.mNodeLibrary.find((*it).mNode);
		if (fnd == pParser.mNodeLibrary.end()) 
			DefaultLogger::get()->error("Collada: Unable to resolve reference to instanced node " + (*it).mNode);
		
		else {
			//	attach this node to the list of children
			resolved.push_back((*fnd).second);
		}
	}
}

// ------------------------------------------------------------------------------------------------
// Resolve UV channels
void ColladaLoader::ApplyVertexToEffectSemanticMapping(Collada::Sampler& sampler,
	 const Collada::SemanticMappingTable& table)
{
	std::map<std::string, Collada::InputSemanticMapEntry>::const_iterator it = table.mMap.find(sampler.mUVChannel);
	if (it != table.mMap.end()) {
		if (it->second.mType != Collada::IT_Texcoord)
			DefaultLogger::get()->error("Collada: Unexpected effect input mapping");

		sampler.mUVId = it->second.mSet;
	}
}

// ------------------------------------------------------------------------------------------------
// Builds lights for the given node and references them
void ColladaLoader::BuildLightsForNode( const ColladaParser& pParser, const Collada::Node* pNode, aiNode* pTarget)
{
	BOOST_FOREACH( const Collada::LightInstance& lid, pNode->mLights)
	{
		// find the referred light
		ColladaParser::LightLibrary::const_iterator srcLightIt = pParser.mLightLibrary.find( lid.mLight);
		if( srcLightIt == pParser.mLightLibrary.end())
		{
			DefaultLogger::get()->warn("Collada: Unable to find light for ID \"" + lid.mLight + "\". Skipping.");
			continue;
		}
		const Collada::Light* srcLight = &srcLightIt->second;
		if (srcLight->mType == aiLightSource_AMBIENT) {
			DefaultLogger::get()->error("Collada: Skipping ambient light for the moment");
			continue;
		}
		
		// now fill our ai data structure
		aiLight* out = new aiLight();
		out->mName = pTarget->mName;
		out->mType = (aiLightSourceType)srcLight->mType;

		// collada lights point in -Z by default, rest is specified in node transform
		out->mDirection = aiVector3D(0.f,0.f,-1.f);

		out->mAttenuationConstant = srcLight->mAttConstant;
		out->mAttenuationLinear = srcLight->mAttLinear;
		out->mAttenuationQuadratic = srcLight->mAttQuadratic;

		// collada doesn't differenciate between these color types
		out->mColorDiffuse = out->mColorSpecular = out->mColorAmbient = srcLight->mColor*srcLight->mIntensity;

		// convert falloff angle and falloff exponent in our representation, if given
		if (out->mType == aiLightSource_SPOT) {
			
			out->mAngleInnerCone = AI_DEG_TO_RAD( srcLight->mFalloffAngle );

			// ... some extension magic. FUCKING COLLADA. 
			if (srcLight->mOuterAngle == 10e10f) 
			{
				// ... some deprecation magic. FUCKING FCOLLADA.
				if (srcLight->mPenumbraAngle == 10e10f) 
				{
					// Need to rely on falloff_exponent. I don't know how to interpret it, so I need to guess ....
					// ci - inner cone angle
					// co - outer cone angle
					// fe - falloff exponent
					// ld - spot direction - normalized
					// rd - ray direction - normalized
					//
					// Formula is:
					// 1. (cos(acos (ld dot rd) - ci))^fe == epsilon
					// 2. (ld dot rd) == cos(acos(epsilon^(1/fe)) + ci)
					// 3. co == acos (ld dot rd)
					// 4. co == acos(epsilon^(1/fe)) + ci)

					// epsilon chosen to be 0.1
					out->mAngleOuterCone = AI_DEG_TO_RAD (acos(pow(0.1f,1.f/srcLight->mFalloffExponent))+
						srcLight->mFalloffAngle);
				}
				else {
					out->mAngleOuterCone = out->mAngleInnerCone + AI_DEG_TO_RAD(  srcLight->mPenumbraAngle );
					if (out->mAngleOuterCone < out->mAngleInnerCone)
						std::swap(out->mAngleInnerCone,out->mAngleOuterCone);
				}
			}
			else out->mAngleOuterCone = AI_DEG_TO_RAD(  srcLight->mOuterAngle );
		}

		// add to light list
		mLights.push_back(out);
	}
}

// ------------------------------------------------------------------------------------------------
// Builds cameras for the given node and references them
void ColladaLoader::BuildCamerasForNode( const ColladaParser& pParser, const Collada::Node* pNode, aiNode* pTarget)
{
	BOOST_FOREACH( const Collada::CameraInstance& cid, pNode->mCameras)
	{
		// find the referred light
		ColladaParser::CameraLibrary::const_iterator srcCameraIt = pParser.mCameraLibrary.find( cid.mCamera);
		if( srcCameraIt == pParser.mCameraLibrary.end())
		{
			DefaultLogger::get()->warn("Collada: Unable to find camera for ID \"" + cid.mCamera + "\". Skipping.");
			continue;
		}
		const Collada::Camera* srcCamera = &srcCameraIt->second;

		// orthographic cameras not yet supported in Assimp
		if (srcCamera->mOrtho) {
			DefaultLogger::get()->warn("Collada: Orthographic cameras are not supported.");
		}

		// now fill our ai data structure
		aiCamera* out = new aiCamera();
		out->mName = pTarget->mName;

		// collada cameras point in -Z by default, rest is specified in node transform
		out->mLookAt = aiVector3D(0.f,0.f,-1.f);

		// near/far z is already ok
		out->mClipPlaneFar = srcCamera->mZFar;
		out->mClipPlaneNear = srcCamera->mZNear;

		// ... but for the rest some values are optional 
		// and we need to compute the others in any combination. FUCKING COLLADA.
		 if (srcCamera->mAspect != 10e10f)
			out->mAspect = srcCamera->mAspect;

		if (srcCamera->mHorFov != 10e10f) {
			out->mHorizontalFOV = srcCamera->mHorFov; 

			if (srcCamera->mVerFov != 10e10f && srcCamera->mAspect != 10e10f) {
				out->mAspect = srcCamera->mHorFov/srcCamera->mVerFov;
			}
		}
		else if (srcCamera->mAspect != 10e10f && srcCamera->mVerFov != 10e10f)	{
			out->mHorizontalFOV = srcCamera->mAspect*srcCamera->mVerFov;
		}

		// Collada uses degrees, we use radians
		out->mHorizontalFOV = AI_DEG_TO_RAD(out->mHorizontalFOV);

		// add to camera list
		mCameras.push_back(out);
	}
}

// ------------------------------------------------------------------------------------------------
// Builds meshes for the given node and references them
void ColladaLoader::BuildMeshesForNode( const ColladaParser& pParser, const Collada::Node* pNode, aiNode* pTarget)
{
	// accumulated mesh references by this node
	std::vector<size_t> newMeshRefs;
	newMeshRefs.reserve(pNode->mMeshes.size());

	// add a mesh for each subgroup in each collada mesh
	BOOST_FOREACH( const Collada::MeshInstance& mid, pNode->mMeshes)
	{
		const Collada::Mesh* srcMesh = NULL;
		const Collada::Controller* srcController = NULL;

		// find the referred mesh
		ColladaParser::MeshLibrary::const_iterator srcMeshIt = pParser.mMeshLibrary.find( mid.mMeshOrController);
		if( srcMeshIt == pParser.mMeshLibrary.end())
		{
			// if not found in the mesh-library, it might also be a controller referring to a mesh
			ColladaParser::ControllerLibrary::const_iterator srcContrIt = pParser.mControllerLibrary.find( mid.mMeshOrController);
			if( srcContrIt != pParser.mControllerLibrary.end())
			{
				srcController = &srcContrIt->second;
				srcMeshIt = pParser.mMeshLibrary.find( srcController->mMeshId);
				if( srcMeshIt != pParser.mMeshLibrary.end())
					srcMesh = srcMeshIt->second;
			}

			if( !srcMesh)
			{
				DefaultLogger::get()->warn( boost::str( boost::format( "Collada: Unable to find geometry for ID \"%s\". Skipping.") % mid.mMeshOrController));
				continue;
			}
		} else
		{
			// ID found in the mesh library -> direct reference to an unskinned mesh
			srcMesh = srcMeshIt->second;
		}

		// build a mesh for each of its subgroups
		size_t vertexStart = 0, faceStart = 0;
		for( size_t sm = 0; sm < srcMesh->mSubMeshes.size(); ++sm)
		{
			const Collada::SubMesh& submesh = srcMesh->mSubMeshes[sm];
			if( submesh.mNumFaces == 0)
				continue;

			// find material assigned to this submesh
			std::map<std::string, Collada::SemanticMappingTable >::const_iterator meshMatIt = mid.mMaterials.find( submesh.mMaterial);

			const Collada::SemanticMappingTable* table;
			if( meshMatIt != mid.mMaterials.end())
				table = &meshMatIt->second;
			else {
				table = NULL;
				DefaultLogger::get()->warn( boost::str( boost::format( "Collada: No material specified for subgroup \"%s\" in geometry \"%s\".") % submesh.mMaterial % mid.mMeshOrController));
			}
			const std::string& meshMaterial = table ? table->mMatName : "";

			// OK ... here the *real* fun starts ... we have the vertex-input-to-effect-semantic-table
			// given. The only mapping stuff which we do actually support is the UV channel.
			std::map<std::string, size_t>::const_iterator matIt = mMaterialIndexByName.find( meshMaterial);
			unsigned int matIdx;
			if( matIt != mMaterialIndexByName.end())
				matIdx = matIt->second;
			else
				matIdx = 0;

			if (table && !table->mMap.empty() ) {
				std::pair<Collada::Effect*, aiMaterial*>&  mat = newMats[matIdx];

				// Iterate through all texture channels assigned to the effect and
				// check whether we have mapping information for it.
				ApplyVertexToEffectSemanticMapping(mat.first->mTexDiffuse,    *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexAmbient,    *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexSpecular,   *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexEmissive,   *table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexTransparent,*table);
				ApplyVertexToEffectSemanticMapping(mat.first->mTexBump,       *table);
			}

			// built lookup index of the Mesh-Submesh-Material combination
			ColladaMeshIndex index( mid.mMeshOrController, sm, meshMaterial);

			// if we already have the mesh at the library, just add its index to the node's array
			std::map<ColladaMeshIndex, size_t>::const_iterator dstMeshIt = mMeshIndexByID.find( index);
			if( dstMeshIt != mMeshIndexByID.end())
			{
				newMeshRefs.push_back( dstMeshIt->second);
			} else
			{
				// else we have to add the mesh to the collection and store its newly assigned index at the node
				aiMesh* dstMesh = CreateMesh( pParser, srcMesh, submesh, srcController, vertexStart, faceStart);

				// store the mesh, and store its new index in the node
				newMeshRefs.push_back( mMeshes.size());
				mMeshIndexByID[index] = mMeshes.size();
				mMeshes.push_back( dstMesh);
				vertexStart += dstMesh->mNumVertices; faceStart += submesh.mNumFaces;

				// assign the material index
				dstMesh->mMaterialIndex = matIdx;
			}
		}
	}

	// now place all mesh references we gathered in the target node
	pTarget->mNumMeshes = newMeshRefs.size();
	if( newMeshRefs.size())
	{
		pTarget->mMeshes = new unsigned int[pTarget->mNumMeshes];
		std::copy( newMeshRefs.begin(), newMeshRefs.end(), pTarget->mMeshes);
	}
}

// ------------------------------------------------------------------------------------------------
// Creates a mesh for the given ColladaMesh face subset and returns the newly created mesh
aiMesh* ColladaLoader::CreateMesh( const ColladaParser& pParser, const Collada::Mesh* pSrcMesh, const Collada::SubMesh& pSubMesh, 
								  const Collada::Controller* pSrcController, size_t pStartVertex, size_t pStartFace)
{
	aiMesh* dstMesh = new aiMesh;

	// count the vertices addressed by its faces
	const size_t numVertices = std::accumulate( pSrcMesh->mFaceSize.begin() + pStartFace,
		pSrcMesh->mFaceSize.begin() + pStartFace + pSubMesh.mNumFaces, 0);

	// copy positions
	dstMesh->mNumVertices = numVertices;
	dstMesh->mVertices = new aiVector3D[numVertices];
	std::copy( pSrcMesh->mPositions.begin() + pStartVertex, pSrcMesh->mPositions.begin() + 
		pStartVertex + numVertices, dstMesh->mVertices);

	// normals, if given. HACK: (thom) Due to the fucking Collada spec we never 
	// know if we have the same number of normals as there are positions. So we 
	// also ignore any vertex attribute if it has a different count
	if( pSrcMesh->mNormals.size() == pSrcMesh->mPositions.size())
	{
		dstMesh->mNormals = new aiVector3D[numVertices];
		std::copy( pSrcMesh->mNormals.begin() + pStartVertex, pSrcMesh->mNormals.begin() +
			pStartVertex + numVertices, dstMesh->mNormals);
	}

	// tangents, if given. 
	if( pSrcMesh->mTangents.size() == pSrcMesh->mPositions.size())
	{
		dstMesh->mTangents = new aiVector3D[numVertices];
		std::copy( pSrcMesh->mTangents.begin() + pStartVertex, pSrcMesh->mTangents.begin() + 
			pStartVertex + numVertices, dstMesh->mTangents);
	}

	// bitangents, if given. 
	if( pSrcMesh->mBitangents.size() == pSrcMesh->mPositions.size())
	{
		dstMesh->mBitangents = new aiVector3D[numVertices];
		std::copy( pSrcMesh->mBitangents.begin() + pStartVertex, pSrcMesh->mBitangents.begin() + 
			pStartVertex + numVertices, dstMesh->mBitangents);
	}

	// same for texturecoords, as many as we have
	for( size_t a = 0; a < AI_MAX_NUMBER_OF_TEXTURECOORDS; a++)
	{
		if( pSrcMesh->mTexCoords[a].size() == pSrcMesh->mPositions.size())
		{
			dstMesh->mTextureCoords[a] = new aiVector3D[numVertices];
			for( size_t b = 0; b < numVertices; ++b)
				dstMesh->mTextureCoords[a][b] = pSrcMesh->mTexCoords[a][pStartVertex+b];
			
			dstMesh->mNumUVComponents[a] = pSrcMesh->mNumUVComponents[a];
		}
	}

	// same for vertex colors, as many as we have
	for( size_t a = 0; a < AI_MAX_NUMBER_OF_COLOR_SETS; a++)
	{
		if( pSrcMesh->mColors[a].size() == pSrcMesh->mPositions.size())
		{
			dstMesh->mColors[a] = new aiColor4D[numVertices];
			std::copy( pSrcMesh->mColors[a].begin() + pStartVertex, pSrcMesh->mColors[a].begin() + pStartVertex + numVertices, dstMesh->mColors[a]);
		}
	}

	// create faces. Due to the fact that each face uses unique vertices, we can simply count up on each vertex
	size_t vertex = 0;
	dstMesh->mNumFaces = pSubMesh.mNumFaces;
	dstMesh->mFaces = new aiFace[dstMesh->mNumFaces];
	for( size_t a = 0; a < dstMesh->mNumFaces; ++a)
	{
		size_t s = pSrcMesh->mFaceSize[ pStartFace + a];
		aiFace& face = dstMesh->mFaces[a];
		face.mNumIndices = s;
		face.mIndices = new unsigned int[s];
		for( size_t b = 0; b < s; ++b)
			face.mIndices[b] = vertex++;
	}

	// create bones if given
	if( pSrcController)
	{
		// refuse if the vertex count does not match
//		if( pSrcController->mWeightCounts.size() != dstMesh->mNumVertices)
//			throw new ImportErrorException( "Joint Controller vertex count does not match mesh vertex count");

		// resolve references - joint names
		const Collada::Accessor& jointNamesAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mJointNameSource);
		const Collada::Data& jointNames = pParser.ResolveLibraryReference( pParser.mDataLibrary, jointNamesAcc.mSource);
		// joint offset matrices
		const Collada::Accessor& jointMatrixAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mJointOffsetMatrixSource);
		const Collada::Data& jointMatrices = pParser.ResolveLibraryReference( pParser.mDataLibrary, jointMatrixAcc.mSource);
		// joint vertex_weight name list - should refer to the same list as the joint names above. If not, report and reconsider
		const Collada::Accessor& weightNamesAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mWeightInputJoints.mAccessor);
		if( &weightNamesAcc != &jointNamesAcc)
			throw new ImportErrorException( "Temporary implementational lazyness. If you read this, please report to the author.");
		// vertex weights
		const Collada::Accessor& weightsAcc = pParser.ResolveLibraryReference( pParser.mAccessorLibrary, pSrcController->mWeightInputWeights.mAccessor);
		const Collada::Data& weights = pParser.ResolveLibraryReference( pParser.mDataLibrary, weightsAcc.mSource);

		if( !jointNames.mIsStringArray || jointMatrices.mIsStringArray || weights.mIsStringArray)
			throw new ImportErrorException( "Data type mismatch while resolving mesh joints");
		// sanity check: we rely on the vertex weights always coming as pairs of BoneIndex-WeightIndex
		if( pSrcController->mWeightInputJoints.mOffset != 0 || pSrcController->mWeightInputWeights.mOffset != 1)
			throw new ImportErrorException( "Unsupported vertex_weight adresssing scheme. Fucking collada spec.");

		// create containers to collect the weights for each bone
		size_t numBones = jointNames.mStrings.size();
		std::vector<std::vector<aiVertexWeight> > dstBones( numBones);

		// build a temporary array of pointers to the start of each vertex's weights
		typedef std::vector< std::pair<size_t, size_t> > IndexPairVector;
		std::vector<IndexPairVector::const_iterator> weightStartPerVertex( pSrcController->mWeightCounts.size());
		IndexPairVector::const_iterator pit = pSrcController->mWeights.begin();
		for( size_t a = 0; a < pSrcController->mWeightCounts.size(); ++a)
		{
			weightStartPerVertex[a] = pit;
			pit += pSrcController->mWeightCounts[a];
		}

		// now for each vertex put the corresponding vertex weights into each bone's weight collection
		for( size_t a = pStartVertex; a < pStartVertex + numVertices; ++a)
		{
			// which position index was responsible for this vertex? that's also the index by which
			// the controller assigns the vertex weights
			size_t orgIndex = pSrcMesh->mFacePosIndices[a];
			// find the vertex weights for this vertex
			IndexPairVector::const_iterator iit = weightStartPerVertex[orgIndex];
			size_t pairCount = pSrcController->mWeightCounts[orgIndex];

			for( size_t b = 0; b < pairCount; ++b, ++iit)
			{
				size_t jointIndex = iit->first;
				size_t vertexIndex = iit->second;

				aiVertexWeight w;
				w.mVertexId = a - pStartVertex;
				w.mWeight = weights.mValues[vertexIndex];
				dstBones[jointIndex].push_back( w);
			}
		}

		// count the number of bones which influence vertices of the current submesh
		size_t numRemainingBones = 0;
		for( std::vector<std::vector<aiVertexWeight> >::const_iterator it = dstBones.begin(); it != dstBones.end(); ++it)
			if( it->size() > 0)
				numRemainingBones++;

		// create bone array and copy bone weights one by one
		dstMesh->mNumBones = numRemainingBones;
		dstMesh->mBones = new aiBone*[numRemainingBones];
		size_t boneCount = 0;
		for( size_t a = 0; a < numBones; ++a)
		{
			// omit bones without weights
			if( dstBones[a].size() == 0)
				continue;

			// create bone with its weights
			aiBone* bone = new aiBone;
			bone->mName = jointNames.mStrings[a];
			bone->mOffsetMatrix.a1 = jointMatrices.mValues[a*16 + 0];
			bone->mOffsetMatrix.a2 = jointMatrices.mValues[a*16 + 1];
			bone->mOffsetMatrix.a3 = jointMatrices.mValues[a*16 + 2];
			bone->mOffsetMatrix.a4 = jointMatrices.mValues[a*16 + 3];
			bone->mOffsetMatrix.b1 = jointMatrices.mValues[a*16 + 4];
			bone->mOffsetMatrix.b2 = jointMatrices.mValues[a*16 + 5];
			bone->mOffsetMatrix.b3 = jointMatrices.mValues[a*16 + 6];
			bone->mOffsetMatrix.b4 = jointMatrices.mValues[a*16 + 7];
			bone->mOffsetMatrix.c1 = jointMatrices.mValues[a*16 + 8];
			bone->mOffsetMatrix.c2 = jointMatrices.mValues[a*16 + 9];
			bone->mOffsetMatrix.c3 = jointMatrices.mValues[a*16 + 10];
			bone->mOffsetMatrix.c4 = jointMatrices.mValues[a*16 + 11];
			bone->mNumWeights = dstBones[a].size();
			bone->mWeights = new aiVertexWeight[bone->mNumWeights];
			std::copy( dstBones[a].begin(), dstBones[a].end(), bone->mWeights);

			// and insert bone
			dstMesh->mBones[boneCount++] = bone;
		}
	}

	return dstMesh;
}

// ------------------------------------------------------------------------------------------------
// Stores all meshes in the given scene
void ColladaLoader::StoreSceneMeshes( aiScene* pScene)
{
	pScene->mNumMeshes = mMeshes.size();
	if( mMeshes.size() > 0)
	{
		pScene->mMeshes = new aiMesh*[mMeshes.size()];
		std::copy( mMeshes.begin(), mMeshes.end(), pScene->mMeshes);
		mMeshes.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all cameras in the given scene
void ColladaLoader::StoreSceneCameras( aiScene* pScene)
{
	pScene->mNumCameras = mCameras.size();
	if( mCameras.size() > 0)
	{
		pScene->mCameras = new aiCamera*[mCameras.size()];
		std::copy( mCameras.begin(), mCameras.end(), pScene->mCameras);
		mCameras.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all lights in the given scene
void ColladaLoader::StoreSceneLights( aiScene* pScene)
{
	pScene->mNumLights = mLights.size();
	if( mLights.size() > 0)
	{
		pScene->mLights = new aiLight*[mLights.size()];
		std::copy( mLights.begin(), mLights.end(), pScene->mLights);
		mLights.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all textures in the given scene
void ColladaLoader::StoreSceneTextures( aiScene* pScene)
{
	pScene->mNumTextures = mTextures.size();
	if( mTextures.size() > 0)
	{
		pScene->mTextures = new aiTexture*[mTextures.size()];
		std::copy( mTextures.begin(), mTextures.end(), pScene->mTextures);
		mTextures.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Stores all materials in the given scene
void ColladaLoader::StoreSceneMaterials( aiScene* pScene)
{
	pScene->mNumMaterials = newMats.size();

	if (newMats.size() > 0) {
		pScene->mMaterials = new aiMaterial*[newMats.size()];
		for (unsigned int i = 0; i < newMats.size();++i)
			pScene->mMaterials[i] = newMats[i].second;

		newMats.clear();
	}
}

// ------------------------------------------------------------------------------------------------
// Add a texture to a material structure
void ColladaLoader::AddTexture ( Assimp::MaterialHelper& mat, const ColladaParser& pParser,
	const Collada::Effect& effect,
	const Collada::Sampler& sampler,
	aiTextureType type, unsigned int idx)
{
	// first of all, basic file name
	mat.AddProperty( &FindFilenameForEffectTexture( pParser, effect, sampler.mName), 
		_AI_MATKEY_TEXTURE_BASE,type,idx);

	// mapping mode
	int map = aiTextureMapMode_Clamp;
	if (sampler.mWrapU)
		map = aiTextureMapMode_Wrap;
	if (sampler.mWrapU && sampler.mMirrorU)
		map = aiTextureMapMode_Mirror;

	mat.AddProperty( &map, 1, _AI_MATKEY_MAPPINGMODE_U_BASE, type, idx);

	map = aiTextureMapMode_Clamp;
	if (sampler.mWrapV)
		map = aiTextureMapMode_Wrap;
	if (sampler.mWrapV && sampler.mMirrorV)
		map = aiTextureMapMode_Mirror;

	mat.AddProperty( &map, 1, _AI_MATKEY_MAPPINGMODE_V_BASE, type, idx);

	// UV transformation
	mat.AddProperty(&sampler.mTransform, 1,
		_AI_MATKEY_UVTRANSFORM_BASE, type, idx);

	// Blend mode
	mat.AddProperty((int*)&sampler.mOp , 1,
		_AI_MATKEY_TEXBLEND_BASE, type, idx);

	// Blend factor
	mat.AddProperty((float*)&sampler.mWeighting , 1,
		_AI_MATKEY_TEXBLEND_BASE, type, idx);

	// UV source index ... if we didn't resolve the mapping it is actually just 
	// a guess but it works in most cases. We search for the frst occurence of a
	// number in the channel name. We assume it is the zero-based index into the
	// UV channel array of all corresponding meshes.
	if (sampler.mUVId != 0xffffffff)
		map = sampler.mUVId;
	else {
		map = 0xffffffff;
		for (std::string::const_iterator it = sampler.mUVChannel.begin();
			it != sampler.mUVChannel.end(); ++it)
		{
			if (IsNumeric(*it)) {
				map = strtol10(&(*it));
				break;
			}
		}
		if (0xffffffff == map) {
			DefaultLogger::get()->warn("Collada: unable to determine UV channel for texture");
			map = 0;
		}
	}
	mat.AddProperty(&map,1,_AI_MATKEY_UVWSRC_BASE,type,idx);
}

// ------------------------------------------------------------------------------------------------
// Fills materials from the collada material definitions
void ColladaLoader::FillMaterials( const ColladaParser& pParser, aiScene* pScene)
{
	for (std::vector<std::pair<Collada::Effect*, aiMaterial*> >::iterator it = newMats.begin(),
		end = newMats.end(); it != end; ++it)
	{
		MaterialHelper&  mat = (MaterialHelper&)*it->second; 
		Collada::Effect& effect = *it->first;

		// resolve shading mode
		int shadeMode;
		if (effect.mFaceted) /* fixme */
			shadeMode = aiShadingMode_Flat;
		else {
			switch( effect.mShadeType)
			{
			case Collada::Shade_Constant: 
				shadeMode = aiShadingMode_NoShading; 
				break;
			case Collada::Shade_Lambert:
				shadeMode = aiShadingMode_Gouraud; 
				break;
			case Collada::Shade_Blinn: 
				shadeMode = aiShadingMode_Blinn;
				break;
			case Collada::Shade_Phong: 
				shadeMode = aiShadingMode_Phong; 
				break;

			default:
				DefaultLogger::get()->warn("Collada: Unrecognized shading mode, using gouraud shading");
				shadeMode = aiShadingMode_Gouraud; 
				break;
			}
		}
		mat.AddProperty<int>( &shadeMode, 1, AI_MATKEY_SHADING_MODEL);

		// double-sided?
		shadeMode = effect.mDoubleSided;
		mat.AddProperty<int>( &shadeMode, 1, AI_MATKEY_TWOSIDED);

		// wireframe?
		shadeMode = effect.mWireframe;
		mat.AddProperty<int>( &shadeMode, 1, AI_MATKEY_ENABLE_WIREFRAME);

		// add material colors
		mat.AddProperty( &effect.mAmbient, 1,AI_MATKEY_COLOR_AMBIENT);
		mat.AddProperty( &effect.mDiffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
		mat.AddProperty( &effect.mSpecular, 1,AI_MATKEY_COLOR_SPECULAR);
		mat.AddProperty( &effect.mEmissive, 1,	AI_MATKEY_COLOR_EMISSIVE);
		mat.AddProperty( &effect.mTransparent, 1, AI_MATKEY_COLOR_TRANSPARENT);
		mat.AddProperty( &effect.mReflective, 1, AI_MATKEY_COLOR_REFLECTIVE);

		// scalar properties
		mat.AddProperty( &effect.mShininess, 1, AI_MATKEY_SHININESS);
		mat.AddProperty( &effect.mRefractIndex, 1, AI_MATKEY_REFRACTI);

		// add textures, if given
		if( !effect.mTexAmbient.mName.empty()) 
			 /* It is merely a lightmap */
			AddTexture( mat, pParser, effect, effect.mTexAmbient, aiTextureType_LIGHTMAP);

		if( !effect.mTexEmissive.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexEmissive, aiTextureType_EMISSIVE);

		if( !effect.mTexSpecular.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexSpecular, aiTextureType_SPECULAR);

		if( !effect.mTexDiffuse.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexDiffuse, aiTextureType_DIFFUSE);

		if( !effect.mTexBump.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexBump, aiTextureType_HEIGHT);

		if( !effect.mTexTransparent.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexTransparent, aiTextureType_OPACITY);

		if( !effect.mTexReflective.mName.empty())
			AddTexture( mat, pParser, effect, effect.mTexReflective, aiTextureType_REFLECTION);
	}
}

// ------------------------------------------------------------------------------------------------
// Constructs materials from the collada material definitions
void ColladaLoader::BuildMaterials( const ColladaParser& pParser, aiScene* pScene)
{
	newMats.reserve(pParser.mMaterialLibrary.size());

	for( ColladaParser::MaterialLibrary::const_iterator matIt = pParser.mMaterialLibrary.begin(); matIt != pParser.mMaterialLibrary.end(); ++matIt)
	{
		const Collada::Material& material = matIt->second;
		// a material is only a reference to an effect
		ColladaParser::EffectLibrary::const_iterator effIt = pParser.mEffectLibrary.find( material.mEffect);
		if( effIt == pParser.mEffectLibrary.end())
			continue;
		const Collada::Effect& effect = effIt->second;

		// create material
		Assimp::MaterialHelper* mat = new Assimp::MaterialHelper;
		aiString name( matIt->first);
		mat->AddProperty(&name,AI_MATKEY_NAME);

		// MEGA SUPER MONSTER HACK by Alex ... It's all my fault, yes.
		// We store the reference to the effect in the material and
		// return ... we'll add the actual material properties later
		// after we processed all meshes. During mesh processing,
		// we evaluate vertex input mappings. Afterwards we should be
		// able to correctly setup source UV channels for textures.

		// ... moved to ColladaLoader::FillMaterials()
		// *duck*

		// store the material
		mMaterialIndexByName[matIt->first] = newMats.size();
		newMats.push_back( std::pair<Collada::Effect*, aiMaterial*>(const_cast<Collada::Effect*>(&effect),mat) );
	}
	// ScenePreprocessor generates a default material automatically if none is there.
	// All further code here in this loader works well without a valid material so
	// we can safely let it to ScenePreprocessor.
#if 0
	if( newMats.size() == 0)
	{
		Assimp::MaterialHelper* mat = new Assimp::MaterialHelper;
		aiString name( AI_DEFAULT_MATERIAL_NAME );
		mat->AddProperty( &name, AI_MATKEY_NAME);

		const int shadeMode = aiShadingMode_Phong;
		mat->AddProperty<int>( &shadeMode, 1, AI_MATKEY_SHADING_MODEL);
		aiColor4D colAmbient( 0.2f, 0.2f, 0.2f, 1.0f), colDiffuse( 0.8f, 0.8f, 0.8f, 1.0f), colSpecular( 0.5f, 0.5f, 0.5f, 0.5f);
		mat->AddProperty( &colAmbient, 1, AI_MATKEY_COLOR_AMBIENT);
		mat->AddProperty( &colDiffuse, 1, AI_MATKEY_COLOR_DIFFUSE);
		mat->AddProperty( &colSpecular, 1, AI_MATKEY_COLOR_SPECULAR);
		const float specExp = 5.0f;
		mat->AddProperty( &specExp, 1, AI_MATKEY_SHININESS);
	}
#endif
}

// ------------------------------------------------------------------------------------------------
// Resolves the texture name for the given effect texture entry
const aiString& ColladaLoader::FindFilenameForEffectTexture( const ColladaParser& pParser,
	const Collada::Effect& pEffect, const std::string& pName)
{
	// recurse through the param references until we end up at an image
	std::string name = pName;
	while( 1)
	{
		// the given string is a param entry. Find it
		Collada::Effect::ParamLibrary::const_iterator it = pEffect.mParams.find( name);
		// if not found, we're at the end of the recursion. The resulting string should be the image ID
		if( it == pEffect.mParams.end())
			break;

		// else recurse on
		name = it->second.mReference;
	}

	// find the image referred by this name in the image library of the scene
	ColladaParser::ImageLibrary::const_iterator imIt = pParser.mImageLibrary.find( name);
	if( imIt == pParser.mImageLibrary.end()) 
	{
		throw new ImportErrorException( boost::str( boost::format( 
			"Collada: Unable to resolve effect texture entry \"%s\", ended up at ID \"%s\".") % pName % name));
	}

	static aiString result;

	// if this is an embedded texture image setup an aiTexture for it
	if (imIt->second.mFileName.empty()) 
	{
		if (imIt->second.mImageData.empty()) 
			throw new ImportErrorException("Collada: Invalid texture, no data or file reference given");

		aiTexture* tex = new aiTexture();

		// setup format hint
		if (imIt->second.mEmbeddedFormat.length() > 3)
			DefaultLogger::get()->warn("Collada: texture format hint is too long, truncating to 3 characters");

		strncpy(tex->achFormatHint,imIt->second.mEmbeddedFormat.c_str(),3);

		// and copy texture data
		tex->mHeight = 0;
		tex->mWidth = imIt->second.mImageData.size();
		tex->pcData = (aiTexel*)new char[tex->mWidth];
		memcpy(tex->pcData,&imIt->second.mImageData[0],tex->mWidth);

		// setup texture reference string
		result.data[0] = '*';
		result.length = 1 + ASSIMP_itoa10(result.data+1,MAXLEN-1,mTextures.size());

		// and add this texture to the list
		mTextures.push_back(tex);
	}
	else 
	{
		result.Set( imIt->second.mFileName );
		ConvertPath(result);
	}
	return result;
}

// ------------------------------------------------------------------------------------------------
// Convert a path read from a collada file to the usual representation
void ColladaLoader::ConvertPath (aiString& ss)
{
	// TODO: collada spec, p 22. Handle URI correctly.
	// For the moment we're just stripping the file:// away to make it work.
	// Windoes doesn't seem to be able to find stuff like
	// 'file://..\LWO\LWO2\MappingModes\earthSpherical.jpg'
	if (0 == strncmp(ss.data,"file://",7)) 
	{
		ss.length -= 7;
		memmove(ss.data,ss.data+7,ss.length);
		ss.data[ss.length] = '\0';
	}
}

#endif // !! ASSIMP_BUILD_NO_DAE_IMPORTER