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

Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

Redistribution and use of this software in source and binary forms, 
with or without modification, are permitted provided that the following 
conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the ASSIMP team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
---------------------------------------------------------------------------
*/

/** @file Implementation of the PLY importer class */
#include "PLYLoader.h"
#include "MaterialSystem.h"

#include "../include/IOStream.h"
#include "../include/IOSystem.h"
#include "../include/aiMesh.h"
#include "../include/aiScene.h"
#include "../include/aiAssert.h"

#include <boost/scoped_ptr.hpp>

using namespace Assimp;


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

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

// ------------------------------------------------------------------------------------------------
// Returns whether the class can handle the format of the given file. 
bool PLYImporter::CanRead( const std::string& pFile, IOSystem* pIOHandler) const
{
	// simple check of file extension is enough for the moment
	std::string::size_type pos = pFile.find_last_of('.');
	// no file extension - can't read
	if( pos == std::string::npos)
		return false;
	std::string extension = pFile.substr( pos);

	if (extension.length() < 4)return false;
	if (extension[0] != '.')return false;
	if (extension[1] != 'p' && extension[1] != 'P')return false;
	if (extension[2] != 'l' && extension[2] != 'L')return false;
	if (extension[3] != 'y' && extension[3] != 'Y')return false;

	return true;
}
// ------------------------------------------------------------------------------------------------
// Imports the given file into the given scene structure. 
void PLYImporter::InternReadFile( 
	const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler)
{
	boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile));

	// Check whether we can read from the file
	if( file.get() == NULL)
	{
		throw new ImportErrorException( "Failed to open PLY file " + pFile + ".");
	}

	// check whether the ply file is large enough to contain
	// at least the file header
	size_t fileSize = file->FileSize();
	if( fileSize < 10)
	{
		throw new ImportErrorException( ".ply File is too small.");
	}

	// allocate storage and copy the contents of the file to a memory buffer
	// (terminate it with zero)
	// FIX: Allocate an extra buffer of 12.5% to be sure we won't crash
	// if an overrun occurs.
	this->mBuffer = new unsigned char[fileSize+1 + (fileSize>>3)];
	file->Read( (void*)mBuffer, 1, fileSize);
	this->mBuffer[fileSize] = '\0';

	// the beginning of the file must be PLY
	if (this->mBuffer[0] != 'P' && this->mBuffer[0] != 'p' ||
		this->mBuffer[1] != 'L' && this->mBuffer[1] != 'l' ||
		this->mBuffer[2] != 'Y' && this->mBuffer[2] != 'y')
	{
		throw new ImportErrorException( "Invalid .ply file: Magic number \'ply\' is no there");
	}
	char* szMe = (char*)&this->mBuffer[3];
	SkipSpacesAndLineEnd(szMe,(const char**)&szMe);
	
	// determine the format of the file data
	PLY::DOM sPlyDom;
	if (0 == ASSIMP_strincmp(szMe,"format",6) && IsSpace(*(szMe+6)))
	{
		szMe += 7;
		if (0 == ASSIMP_strincmp(szMe,"ascii",5) && IsSpace(*(szMe+5)))
		{
			szMe += 6;
			SkipLine(szMe,(const char**)&szMe);
			if(!PLY::DOM::ParseInstance(szMe,&sPlyDom, fileSize))
			{
				throw new ImportErrorException( "Invalid .ply file: Unable to build DOM (#1)");
			}
		}
		else if (0 == ASSIMP_strincmp(szMe,"binary_",7))
		{
			bool bIsBE = false;

			// binary_little_endian
			// binary_big_endian
			szMe += 7;
#if (defined AI_BUILD_BIG_ENDIAN)
			if ('l' == *szMe || 'L' == *szMe)bIsBE = true;
#else
			if ('b' == *szMe || 'B' == *szMe)bIsBE = true;
#endif // ! AI_BUILD_BIG_ENDIAN

			// skip the line, parse the rest of the header and build the DOM
			SkipLine(szMe,(const char**)&szMe);
			if(!PLY::DOM::ParseInstanceBinary(szMe,&sPlyDom,bIsBE, fileSize))
			{
				throw new ImportErrorException( "Invalid .ply file: Unable to build DOM (#2)");
			}
		}
		else
		{
			throw new ImportErrorException( "Invalid .ply file: Unknown file format");
		}
	}
	else
	{
		throw new ImportErrorException( "Invalid .ply file: Missing format specification");
	}
	this->pcDOM = &sPlyDom;

	// now load a list of vertices. This must be sucessfull in order to procede
	std::vector<aiVector3D> avPositions;
	this->LoadVertices(&avPositions,false);

	if (avPositions.empty())
	{
		throw new ImportErrorException( "Invalid .ply file: No vertices found");
	}

	// now load a list of normals. 
	std::vector<aiVector3D> avNormals;
	this->LoadVertices(&avNormals,true);

	// load the face list
	std::vector<PLY::Face> avFaces;
	this->LoadFaces(&avFaces);

	// if no face list is existing we assume that the vertex
	// list is containing a list of triangles
	if (avFaces.empty())
	{
		if (avPositions.size() < 3)
		{
			throw new ImportErrorException( "Invalid .ply file: Not enough vertices to build "
				"a face list. ");
		}

		unsigned int iNum = avPositions.size() / 3;
		for (unsigned int i = 0; i< iNum;++i)
		{
			PLY::Face sFace;
			sFace.mIndices.push_back((iNum*3));
			sFace.mIndices.push_back((iNum*3)+1);
			sFace.mIndices.push_back((iNum*3)+2);
			avFaces.push_back(sFace);
		}
	}

	// now load a list of all materials
	std::vector<MaterialHelper*> avMaterials;
	this->LoadMaterial(&avMaterials);

	// now load a list of all vertex color channels
	std::vector<aiColor4D> avColors;
	this->LoadVertexColor(&avColors);

	// now try to load texture coordinates
	std::vector<aiVector2D> avTexCoords;
	this->LoadTextureCoordinates(&avTexCoords);

	// now replace the default material in all faces and validate all material indices
	this->ReplaceDefaultMaterial(&avFaces,&avMaterials);

	// now convert this to a list of aiMesh instances
	std::vector<aiMesh*> avMeshes;
	this->ConvertMeshes(&avFaces,&avPositions,&avNormals,
		&avColors,&avTexCoords,&avMaterials,&avMeshes);

	if (avMeshes.empty())
	{
		throw new ImportErrorException( "Invalid .ply file: Unable to extract mesh data ");
	}

	// now generate the output scene object. Fill the material list
	pScene->mNumMaterials = avMaterials.size();
	pScene->mMaterials = new aiMaterial*[pScene->mNumMaterials];
	for (unsigned int i = 0; i < pScene->mNumMaterials;++i)
		pScene->mMaterials[i] = avMaterials[i];

	// fill the mesh list
	pScene->mNumMeshes = avMeshes.size();
	pScene->mMeshes = new aiMesh*[pScene->mNumMeshes];
	for (unsigned int i = 0; i < pScene->mNumMeshes;++i)
		pScene->mMeshes[i] = avMeshes[i];

	// generate a simple node structure
	pScene->mRootNode = new aiNode();
	pScene->mRootNode->mNumMeshes = pScene->mNumMeshes;
	pScene->mRootNode->mMeshes = new unsigned int[pScene->mNumMeshes];

	for (unsigned int i = 0; i < pScene->mRootNode->mNumMeshes;++i)
		pScene->mRootNode->mMeshes[i] = i;

	// delete the file buffer
	delete[] this->mBuffer;

	// DOM is lying on the stack, will be deconstructed automatically
	return;
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::ConvertMeshes(std::vector<PLY::Face>* avFaces,
	const std::vector<aiVector3D>*			avPositions,
	const std::vector<aiVector3D>*			avNormals,
	const std::vector<aiColor4D>*			avColors,
	const std::vector<aiVector2D>*			avTexCoords,
	const std::vector<MaterialHelper*>*		avMaterials,
	std::vector<aiMesh*>* avOut)
{
	ai_assert(NULL != avFaces);
	ai_assert(NULL != avPositions);
	ai_assert(NULL != avMaterials);

	// split by materials
	std::vector<unsigned int>* aiSplit = new std::vector<unsigned int>[
		avMaterials->size()];

	unsigned int iNum = 0;
	for (std::vector<PLY::Face>::const_iterator
		i =  avFaces->begin();
		i != avFaces->end();++i,++iNum)
	{
		// index has already been checked
		aiSplit[(*i).iMaterialIndex].push_back(iNum);
	}
	// now generate submeshes
	for (unsigned int p = 0; p < avMaterials->size();++p)
	{
		if (aiSplit[p].size() != 0)
		{
			// allocate the mesh object
			aiMesh* p_pcOut = new aiMesh();
			p_pcOut->mMaterialIndex = p;

			p_pcOut->mNumFaces = aiSplit[p].size();
			p_pcOut->mFaces = new aiFace[aiSplit[p].size()];

			// at first we need to determine the size of the output vector array
			unsigned int iNum = 0;
			for (unsigned int i = 0; i < aiSplit[p].size();++i)
			{
				iNum += (*avFaces)[aiSplit[p][i]].mIndices.size();
			}
			p_pcOut->mNumVertices = iNum;
			p_pcOut->mVertices = new aiVector3D[iNum];

			if (!avColors->empty())
				p_pcOut->mColors[0] = new aiColor4D[iNum];
			if (!avTexCoords->empty())
			{
				p_pcOut->mNumUVComponents[0] = 2;
				p_pcOut->mTextureCoords[0] = new aiVector3D[iNum];
			}
			if (!avNormals->empty())
				p_pcOut->mNormals = new aiVector3D[iNum];

			// add all faces
			iNum = 0;
			unsigned int iVertex = 0;
			for (std::vector<unsigned int>::const_iterator
				i =  aiSplit[p].begin();
				i != aiSplit[p].end();++i,++iNum)
			{
				p_pcOut->mFaces[iNum].mNumIndices = (*avFaces)[*i].mIndices.size(); 
				p_pcOut->mFaces[iNum].mIndices = new unsigned int[p_pcOut->mFaces[iNum].mNumIndices];

				// build an unique set of vertices/colors for this face
				for (unsigned int q = 0; q <  p_pcOut->mFaces[iNum].mNumIndices;++q)
				{
					p_pcOut->mFaces[iNum].mIndices[q] = iVertex;
					p_pcOut->mVertices[iVertex] = (*avPositions)[(*avFaces)[*i].mIndices[q]];

					if (!avColors->empty())
						p_pcOut->mColors[0][iVertex] = (*avColors)[(*avFaces)[*i].mIndices[q]];

					if (!avTexCoords->empty())
					{
						const aiVector2D& vec = (*avTexCoords)[(*avFaces)[*i].mIndices[q]];
						p_pcOut->mTextureCoords[0][iVertex].x = vec.x;
						p_pcOut->mTextureCoords[0][iVertex].y = vec.y;
					}

					if (!avNormals->empty())
						p_pcOut->mNormals[iVertex] = (*avNormals)[(*avFaces)[*i].mIndices[q]];
					iVertex++;
				}

			}
			// add the mesh to the output list
			avOut->push_back(p_pcOut);
		}
	}
	delete[] aiSplit;
	return;
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::ReplaceDefaultMaterial(std::vector<PLY::Face>* avFaces,
										 std::vector<MaterialHelper*>* avMaterials)
{
	bool bNeedDefaultMat = false;

	for (std::vector<PLY::Face>::iterator
		i =  avFaces->begin();i != avFaces->end();++i)
	{
		if (0xFFFFFFFF == (*i).iMaterialIndex)
		{
			bNeedDefaultMat = true;
			(*i).iMaterialIndex = avMaterials->size();
		}
		else if ((*i).iMaterialIndex >= avMaterials->size() )
		{
			// clamp the index
			(*i).iMaterialIndex = avMaterials->size()-1;
		}
	}

	if (bNeedDefaultMat)
	{
		// generate a default material
		MaterialHelper* pcHelper = new MaterialHelper();

		// fill in a default material
		int iMode = (int)aiShadingMode_Gouraud;
		pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

		aiColor3D clr;
		clr.b = clr.g = clr.r = 0.6f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_DIFFUSE);
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_SPECULAR);

		clr.b = clr.g = clr.r = 0.05f;
		pcHelper->AddProperty<aiColor3D>(&clr, 1,AI_MATKEY_COLOR_AMBIENT);

		avMaterials->push_back(pcHelper);
	}
	return;
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::LoadTextureCoordinates(std::vector<aiVector2D>* pvOut)
{
	ai_assert(NULL != pvOut);

	unsigned int aiPositions[2] = {0xFFFFFFFF,0xFFFFFFFF};
	PLY::EDataType aiTypes[2];
	PLY::ElementInstanceList* pcList = NULL;
	unsigned int cnt = 0;

	// serach in the DOM for a vertex entry
	unsigned int _i = 0;
	for (std::vector<PLY::Element*>::const_iterator
		i =  this->pcDOM->alElements.begin();
		i != this->pcDOM->alElements.end();++i,++_i)
	{
		if (PLY::EEST_Vertex == (*i)->eSemantic)
		{
			pcList = this->pcDOM->alElementData[_i];

			// now check whether which normal components are available
			unsigned int _a = 0;
			for (std::vector<PLY::Property*>::const_iterator
				a =  (*i)->alProperties.begin();
				a != (*i)->alProperties.end();++a,++_a)
			{
				if ((*a)->bIsList)continue;
				if (PLY::EST_UTextureCoord == (*a)->Semantic)
				{
					cnt++;
					aiPositions[0] = _a;
					aiTypes[0] = (*a)->eType;
				}
				else if (PLY::EST_VTextureCoord == (*a)->Semantic)
				{
					cnt++;
					aiPositions[1] = _a;
					aiTypes[1] = (*a)->eType;
				}
			}
		}
	}
	// check whether we have a valid source for the texture coordinates data
	if (NULL != pcList && 0 != cnt)
	{
		pvOut->reserve(pcList->alInstances.size());
		for (std::vector<ElementInstance*>::const_iterator
			i =  pcList->alInstances.begin();
			i != pcList->alInstances.end();++i)
		{
			// convert the vertices to sp floats
			aiVector2D vOut;

			if (0xFFFFFFFF != aiPositions[0])
			{
				vOut.x = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[aiPositions[0]].avList.front(),aiTypes[0]);
			}

			if (0xFFFFFFFF != aiPositions[1])
			{
				vOut.y = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[aiPositions[1]].avList.front(),aiTypes[1]);
			}
			// and add them to our nice list
			pvOut->push_back(vOut);
		}
	}
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::LoadVertices(std::vector<aiVector3D>* pvOut, bool p_bNormals)
{
	ai_assert(NULL != pvOut);

	unsigned int aiPositions[3] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
	PLY::EDataType aiTypes[3];
	PLY::ElementInstanceList* pcList = NULL;
	unsigned int cnt = 0;

	// serach in the DOM for a vertex entry
	unsigned int _i = 0;
	for (std::vector<PLY::Element*>::const_iterator
		i =  this->pcDOM->alElements.begin();
		i != this->pcDOM->alElements.end();++i,++_i)
	{
		if (PLY::EEST_Vertex == (*i)->eSemantic)
		{
			pcList = this->pcDOM->alElementData[_i];

			// load normal vectors?
			if (p_bNormals)
			{
				// now check whether which normal components are available
				unsigned int _a = 0;
				for (std::vector<PLY::Property*>::const_iterator
					a =  (*i)->alProperties.begin();
					a != (*i)->alProperties.end();++a,++_a)
				{
					if ((*a)->bIsList)continue;
					if (PLY::EST_XNormal == (*a)->Semantic)
					{
						cnt++;
						aiPositions[0] = _a;
						aiTypes[0] = (*a)->eType;
					}
					else if (PLY::EST_YNormal == (*a)->Semantic)
					{
						cnt++;
						aiPositions[1] = _a;
						aiTypes[1] = (*a)->eType;
					}
					else if (PLY::EST_ZNormal == (*a)->Semantic)
					{
						cnt++;
						aiPositions[2] = _a;
						aiTypes[2] = (*a)->eType;
					}
				}
			}
			// load vertex coordinates
			else
			{
				// now check whether which coordinate sets are available
				unsigned int _a = 0;
				for (std::vector<PLY::Property*>::const_iterator
					a =  (*i)->alProperties.begin();
					a != (*i)->alProperties.end();++a,++_a)
				{
					if ((*a)->bIsList)continue;
					if (PLY::EST_XCoord == (*a)->Semantic)
					{
						cnt++;
						aiPositions[0] = _a;
						aiTypes[0] = (*a)->eType;
					}
					else if (PLY::EST_YCoord == (*a)->Semantic)
					{
						cnt++;
						aiPositions[1] = _a;
						aiTypes[1] = (*a)->eType;
					}
					else if (PLY::EST_ZCoord == (*a)->Semantic)
					{
						cnt++;
						aiPositions[2] = _a;
						aiTypes[2] = (*a)->eType;
					}
					if (3 == cnt)break; 
				}
			}
			break;
		}
	}
	// check whether we have a valid source for the vertex data
	if (NULL != pcList && 0 != cnt)
	{
		pvOut->reserve(pcList->alInstances.size());
		for (std::vector<ElementInstance*>::const_iterator
			i =  pcList->alInstances.begin();
			i != pcList->alInstances.end();++i)
		{
			// convert the vertices to sp floats
			aiVector3D vOut;

			if (0xFFFFFFFF != aiPositions[0])
			{
				vOut.x = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[aiPositions[0]].avList.front(),aiTypes[0]);
			}

			if (0xFFFFFFFF != aiPositions[1])
			{
				vOut.y = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[aiPositions[1]].avList.front(),aiTypes[1]);
			}

			if (0xFFFFFFFF != aiPositions[2])
			{
				vOut.z = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[aiPositions[2]].avList.front(),aiTypes[2]);
			}

			// and add them to our nice list
			pvOut->push_back(vOut);
		}
	}
	return;
}
// ------------------------------------------------------------------------------------------------
float PLYImporter::NormalizeColorValue (PLY::PropertyInstance::ValueUnion val,
	PLY::EDataType eType)
{
	switch (eType)
	{
	case EDT_Float:
		return val.fFloat;
	case EDT_Double:
		return (float)val.fDouble;

	case EDT_UChar:
		return (float)val.iUInt / (float)0xFF;
	case EDT_Char:
		return (float)(val.iInt+(0xFF/2)) / (float)0xFF;
	case EDT_UShort:
		return (float)val.iUInt / (float)0xFFFF;
	case EDT_Short:
		return (float)(val.iInt+(0xFFFF/2)) / (float)0xFFFF;
	case EDT_UInt:
		return (float)val.iUInt / (float)0xFFFF;
	case EDT_Int:
		return ((float)val.iInt / (float)0xFF) + 0.5f;
	};
	return 0.0f;
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::LoadVertexColor(std::vector<aiColor4D>* pvOut)
{
	ai_assert(NULL != pvOut);

	unsigned int aiPositions[4] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
	PLY::EDataType aiTypes[4];
	unsigned int cnt = 0;
	PLY::ElementInstanceList* pcList = NULL;

	// serach in the DOM for a vertex entry
	unsigned int _i = 0;
	for (std::vector<PLY::Element*>::const_iterator
		i =  this->pcDOM->alElements.begin();
		i != this->pcDOM->alElements.end();++i,++_i)
	{
		if (PLY::EEST_Vertex == (*i)->eSemantic)
		{
			pcList = this->pcDOM->alElementData[_i];

			// now check whether which coordinate sets are available
			unsigned int _a = 0;
			for (std::vector<PLY::Property*>::const_iterator
				a =  (*i)->alProperties.begin();
				a != (*i)->alProperties.end();++a,++_a)
			{
				if ((*a)->bIsList)continue;
				if (PLY::EST_Red == (*a)->Semantic)
				{
					cnt++;
					aiPositions[0] = _a;
					aiTypes[0] = (*a)->eType;
				}
				else if (PLY::EST_Green == (*a)->Semantic)
				{
					cnt++;
					aiPositions[1] = _a;
					aiTypes[1] = (*a)->eType;
				}
				else if (PLY::EST_Blue == (*a)->Semantic)
				{
					cnt++;
					aiPositions[2] = _a;
					aiTypes[2] = (*a)->eType;
				}
				else if (PLY::EST_Alpha == (*a)->Semantic)
				{
					cnt++;
					aiPositions[3] = _a;
					aiTypes[3] = (*a)->eType;
				}
				if (4 == cnt)break; 
			}
			break;
		}
	}
	// check whether we have a valid source for the vertex data
	if (NULL != pcList && 0 != cnt)
	{
		pvOut->reserve(pcList->alInstances.size());
		for (std::vector<ElementInstance*>::const_iterator
			i =  pcList->alInstances.begin();
			i != pcList->alInstances.end();++i)
		{
			// convert the vertices to sp floats
			aiColor4D vOut;
			
			if (0xFFFFFFFF != aiPositions[0])
			{
				vOut.r = NormalizeColorValue((*i)->alProperties[
					aiPositions[0]].avList.front(),aiTypes[0]);
			}

			if (0xFFFFFFFF != aiPositions[1])
			{
				vOut.g = NormalizeColorValue((*i)->alProperties[
					aiPositions[1]].avList.front(),aiTypes[1]);
			}

			if (0xFFFFFFFF != aiPositions[2])
			{
				vOut.b = NormalizeColorValue((*i)->alProperties[
					aiPositions[2]].avList.front(),aiTypes[2]);
			}

			// assume 1.0 for the alpha channel ifit is not set
			if (0xFFFFFFFF == aiPositions[3])vOut.a = 1.0f;
			else
			{
				vOut.a = NormalizeColorValue((*i)->alProperties[
					aiPositions[3]].avList.front(),aiTypes[3]);
			}

			// and add them to our nice list
			pvOut->push_back(vOut);
		}
	}
	return;
}

// ------------------------------------------------------------------------------------------------
void PLYImporter::LoadFaces(std::vector<PLY::Face>* pvOut)
{
	ai_assert(NULL != pvOut);

	PLY::ElementInstanceList* pcList = NULL;
	bool bOne = false;

	// index of the vertex index list
	unsigned int iProperty = 0xFFFFFFFF;
	PLY::EDataType eType;
	bool bIsTristrip = false;

	// index of the material index property
	unsigned int iMaterialIndex = 0xFFFFFFFF;
	PLY::EDataType eType2;

	// serach in the DOM for a face entry
	unsigned int _i = 0;
	for (std::vector<PLY::Element*>::const_iterator 
		i =  this->pcDOM->alElements.begin();
		i != this->pcDOM->alElements.end();++i,++_i)
	{
		// face = unique number of vertex indices
		if (PLY::EEST_Face == (*i)->eSemantic)
		{
			pcList = this->pcDOM->alElementData[_i];
			unsigned int _a = 0;
			for (std::vector<PLY::Property*>::const_iterator 
				a =  (*i)->alProperties.begin();
				a != (*i)->alProperties.end();++a,++_a)
			{
				if (PLY::EST_VertexIndex == (*a)->Semantic)
				{
					// must be a dynamic list!
					if (!(*a)->bIsList)continue;
					iProperty	= _a;
					bOne		= true;
					eType		= (*a)->eType;		
				}
				else if (PLY::EST_MaterialIndex == (*a)->Semantic)
				{
					if ((*a)->bIsList)continue;
					iMaterialIndex	= _a;
					bOne			= true;
					eType2		= (*a)->eType;		
				}
			}
			break;
		}
		// triangle strip
		// TODO: triangle strip and material index support???
		else if (PLY::EEST_TriStrip == (*i)->eSemantic)
		{
			// find a list property in this ...
			pcList = this->pcDOM->alElementData[_i];
			unsigned int _a = 0;
			for (std::vector<PLY::Property*>::const_iterator 
				a =  (*i)->alProperties.begin();
				a != (*i)->alProperties.end();++a,++_a)
			{
				// must be a dynamic list!
				if (!(*a)->bIsList)continue;
				iProperty	= _a;
				bOne		= true;
				bIsTristrip	= true;
				eType		= (*a)->eType;	
				break;
			}
			break;
		}
	}
	// check whether we have at least one per-face information set
	if (pcList && bOne)
	{
		if (!bIsTristrip)
		{
			pvOut->reserve(pcList->alInstances.size());
			for (std::vector<ElementInstance*>::const_iterator 
				i =  pcList->alInstances.begin();
				i != pcList->alInstances.end();++i)
			{
				PLY::Face sFace;

				// parse the list of vertex indices
				if (0xFFFFFFFF != iProperty)
				{
					const unsigned int iNum = (*i)->alProperties[iProperty].avList.size();
					sFace.mIndices.resize(iNum);

					if (3 > iNum)
					{
						// We must filter out all degenerates. Leave a message
						// in the log ...
						// LOG
						continue;
					}

					std::list<PLY::PropertyInstance::ValueUnion>::const_iterator p = 
						(*i)->alProperties[iProperty].avList.begin();

					for (unsigned int a = 0; a < iNum;++a,++p)
					{
						sFace.mIndices[a] = PLY::PropertyInstance::ConvertTo<unsigned int>(*p,eType);
					}
				}

				// parse the material index
				if (0xFFFFFFFF != iMaterialIndex)
				{
					sFace.iMaterialIndex = PLY::PropertyInstance::ConvertTo<unsigned int>(
						(*i)->alProperties[iMaterialIndex].avList.front(),eType2);
				}
				pvOut->push_back(sFace);
			}
		}
		else // triangle strips
		{
			// normally we have only one triangle strip instance where
			// a value of -1 indicates a restart of the strip
			for (std::vector<ElementInstance*>::const_iterator
				i =  pcList->alInstances.begin();
				i != pcList->alInstances.end();++i)
			{
				int aiTable[2] = {-1,-1};
				for (std::list<PLY::PropertyInstance::ValueUnion>::const_iterator 
					a =  (*i)->alProperties[iProperty].avList.begin();
					a != (*i)->alProperties[iProperty].avList.end();++a)
				{
					int p = PLY::PropertyInstance::ConvertTo<int>(*a,eType);
					if (-1 == p)
					{
						// restart the strip ...
						aiTable[0] = aiTable[1] = -1;
						continue;
					}
					if (-1 == aiTable[0])
					{
						aiTable[0] = p;
						continue;
					}
					if (-1 == aiTable[1])
					{
						aiTable[1] = p;
						continue;
					}
				
					PLY::Face sFace;
					sFace.mIndices.push_back((unsigned int)aiTable[0]);
					sFace.mIndices.push_back((unsigned int)aiTable[1]);
					sFace.mIndices.push_back((unsigned int)p);
					pvOut->push_back(sFace);

					aiTable[0] = aiTable[1];
					aiTable[1] = p;
				}
			}
		}
	}
	return;
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::GetMaterialColor(const std::vector<PLY::PropertyInstance>& avList,
	unsigned int aiPositions[4], 
	PLY::EDataType aiTypes[4],
	 aiColor4D* clrOut)
{
	ai_assert(NULL != clrOut);

	if (0xFFFFFFFF == aiPositions[0])clrOut->r = 0.0f;
	else
	{
		clrOut->r = NormalizeColorValue(avList[
			aiPositions[0]].avList.front(),aiTypes[0]);
	}

	if (0xFFFFFFFF == aiPositions[1])clrOut->g = 0.0f;
	else
	{
		clrOut->g = NormalizeColorValue(avList[
			aiPositions[1]].avList.front(),aiTypes[1]);
	}

	if (0xFFFFFFFF == aiPositions[2])clrOut->b = 0.0f;
	else
	{
		clrOut->b = NormalizeColorValue(avList[
			aiPositions[2]].avList.front(),aiTypes[2]);
	}

	// assume 1.0 for the alpha channel ifit is not set
	if (0xFFFFFFFF == aiPositions[3])clrOut->a = 1.0f;
	else
	{
		clrOut->a = NormalizeColorValue(avList[
			aiPositions[3]].avList.front(),aiTypes[3]);
	}

	return;
}
// ------------------------------------------------------------------------------------------------
void PLYImporter::LoadMaterial(std::vector<MaterialHelper*>* pvOut)
{
	ai_assert(NULL != pvOut);

	// diffuse[4], specular[4], ambient[4]
	// rgba order
	unsigned int aaiPositions[3][4] = {

		{0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
		{0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
		{0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
	};

	// dto.
	PLY::EDataType aaiTypes[3][4];
	PLY::ElementInstanceList* pcList = NULL;

	unsigned int iPhong = 0xFFFFFFFF;
	PLY::EDataType ePhong;

	unsigned int iOpacity = 0xFFFFFFFF;
	PLY::EDataType eOpacity;

	// serach in the DOM for a vertex entry
	unsigned int _i = 0;
	for (std::vector<PLY::Element*>::const_iterator
		i =  this->pcDOM->alElements.begin();
		i != this->pcDOM->alElements.end();++i,++_i)
	{
		if (PLY::EEST_Material == (*i)->eSemantic)
		{
			pcList = this->pcDOM->alElementData[_i];

			// now check whether which coordinate sets are available
			unsigned int _a = 0;
			for (std::vector<PLY::Property*>::const_iterator
				a =  (*i)->alProperties.begin();
				a != (*i)->alProperties.end();++a,++_a)
			{
				if ((*a)->bIsList)continue;

				// pohng specularity      -----------------------------------
				if (PLY::EST_PhongPower == (*a)->Semantic)
				{
					iPhong		= _a;
					ePhong		= (*a)->eType;
				}

				// general opacity        -----------------------------------
				if (PLY::EST_Opacity == (*a)->Semantic)
				{
					iOpacity		= _a;
					eOpacity		= (*a)->eType;
				}

				// diffuse color channels -----------------------------------
				if (PLY::EST_DiffuseRed == (*a)->Semantic)
				{
					aaiPositions[0][0]	= _a;
					aaiTypes[0][0]		= (*a)->eType;
				}
				else if (PLY::EST_DiffuseGreen == (*a)->Semantic)
				{
					aaiPositions[0][1]	= _a;
					aaiTypes[0][1]		= (*a)->eType;
				}
				else if (PLY::EST_DiffuseBlue == (*a)->Semantic)
				{
					aaiPositions[0][2]	= _a;
					aaiTypes[0][2]		= (*a)->eType;
				}
				else if (PLY::EST_DiffuseAlpha == (*a)->Semantic)
				{
					aaiPositions[0][3]	= _a;
					aaiTypes[0][3]		= (*a)->eType;
				}
				// specular color channels -----------------------------------
				else if (PLY::EST_SpecularRed == (*a)->Semantic)
				{
					aaiPositions[1][0]	= _a;
					aaiTypes[1][0]		= (*a)->eType;
				}
				else if (PLY::EST_SpecularGreen == (*a)->Semantic)
				{
					aaiPositions[1][1]	= _a;
					aaiTypes[1][1]		= (*a)->eType;
				}
				else if (PLY::EST_SpecularBlue == (*a)->Semantic)
				{
					aaiPositions[1][2]	= _a;
					aaiTypes[1][2]		= (*a)->eType;
				}
				else if (PLY::EST_SpecularAlpha == (*a)->Semantic)
				{
					aaiPositions[1][3]	= _a;
					aaiTypes[1][3]		= (*a)->eType;
				}
				// ambient color channels -----------------------------------
				else if (PLY::EST_AmbientRed == (*a)->Semantic)
				{
					aaiPositions[2][0]	= _a;
					aaiTypes[2][0]		= (*a)->eType;
				}
				else if (PLY::EST_AmbientGreen == (*a)->Semantic)
				{
					aaiPositions[2][1]	= _a;
					aaiTypes[2][1]		= (*a)->eType;
				}
				else if (PLY::EST_AmbientBlue == (*a)->Semantic)
				{
					aaiPositions[22][2]	= _a;
					aaiTypes[2][2]		= (*a)->eType;
				}
				else if (PLY::EST_AmbientAlpha == (*a)->Semantic)
				{
					aaiPositions[2][3]	= _a;
					aaiTypes[2][3]		= (*a)->eType;
				}
			}
			break;
		}
	}
	// check whether we have a valid source for the material data
	if (NULL != pcList)
	{
		for (std::vector<ElementInstance*>::const_iterator
			i =  pcList->alInstances.begin();
			i != pcList->alInstances.end();++i)
		{
			aiColor4D clrOut;
			MaterialHelper* pcHelper = new MaterialHelper();
	
			// build the diffuse material color
			GetMaterialColor((*i)->alProperties,aaiPositions[0],aaiTypes[0],&clrOut);
			pcHelper->AddProperty<aiColor4D>(&clrOut,1,AI_MATKEY_COLOR_DIFFUSE);

			// build the specular material color
			GetMaterialColor((*i)->alProperties,aaiPositions[1],aaiTypes[1],&clrOut);
			pcHelper->AddProperty<aiColor4D>(&clrOut,1,AI_MATKEY_COLOR_SPECULAR);

			// build the ambient material color
			GetMaterialColor((*i)->alProperties,aaiPositions[2],aaiTypes[2],&clrOut);
			pcHelper->AddProperty<aiColor4D>(&clrOut,1,AI_MATKEY_COLOR_AMBIENT);

			// handle phong power and shading mode
			int iMode;
			if (0xFFFFFFFF != iPhong)
			{
				float fSpec = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[iPhong].avList.front(),ePhong);

				// if shininess is 0 (and the pow() calculation would therefore always
				// become 1, not depending on the angle) use gouraud lighting
				if (0.0f != fSpec)
				{

					// scale this with 15 ... hopefully this is correct
					fSpec *= 15;
					pcHelper->AddProperty<float>(&fSpec, 1, AI_MATKEY_SHININESS);

					iMode = (int)aiShadingMode_Phong;
				}
				else iMode = (int)aiShadingMode_Gouraud;
			}
			else iMode = (int)aiShadingMode_Gouraud;
			pcHelper->AddProperty<int>(&iMode, 1, AI_MATKEY_SHADING_MODEL);

			// handle opacity
			if (0xFFFFFFFF != iOpacity)
			{
				float fOpacity = PLY::PropertyInstance::ConvertTo<float>(
					(*i)->alProperties[iPhong].avList.front(),eOpacity);

				pcHelper->AddProperty<float>(&fOpacity, 1, AI_MATKEY_OPACITY);
			}

			// add the newly created material instance to the list
			pvOut->push_back(pcHelper);
		}
	}
	return;
}