text: /*
  ---------------------------------------------------------------------------
  Open Asset Import Library (assimp)
  ---------------------------------------------------------------------------
  
  Copyright (c) 2006-2015, assimp team
  
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  copyright notice, this list of conditions and the
  following disclaimer.
  
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  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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  */
  
  /** @file ColladaParser.cpp
   *  @brief Implementation of the Collada parser helper
   */
  
  
  #ifndef ASSIMP_BUILD_NO_COLLADA_IMPORTER
  
  #include <sstream>
  #include "ColladaParser.h"
  #include "fast_atof.h"
  #include "ParsingUtils.h"
  #include <boost/scoped_ptr.hpp>
  #include <boost/foreach.hpp>
  #include "../include/assimp/DefaultLogger.hpp"
  #include "../include/assimp/IOSystem.hpp"
  #include "../include/assimp/light.h"
  
  
  using namespace Assimp;
  using namespace Assimp::Collada;
  
  // ------------------------------------------------------------------------------------------------
  // Constructor to be privately used by Importer
  ColladaParser::ColladaParser( IOSystem* pIOHandler, const std::string& pFile)
      : mFileName( pFile)
  {
      mRootNode = NULL;
      mUnitSize = 1.0f;
      mUpDirection = UP_Y;
  
      // We assume the newest file format by default
      mFormat = FV_1_5_n;
  
    // open the file
    boost::scoped_ptr<IOStream> file( pIOHandler->Open( pFile));
    if( file.get() == NULL)
      throw DeadlyImportError( "Failed to open file " + pFile + ".");
  
      // generate a XML reader for it
    boost::scoped_ptr<CIrrXML_IOStreamReader> mIOWrapper( new CIrrXML_IOStreamReader( file.get()));
      mReader = irr::io::createIrrXMLReader( mIOWrapper.get());
      if( !mReader)
          ThrowException( "Collada: Unable to open file.");
  
      // start reading
      ReadContents();
  }
  
  // ------------------------------------------------------------------------------------------------
  // Destructor, private as well
  ColladaParser::~ColladaParser()
  {
      delete mReader;
      for( NodeLibrary::iterator it = mNodeLibrary.begin(); it != mNodeLibrary.end(); ++it)
          delete it->second;
      for( MeshLibrary::iterator it = mMeshLibrary.begin(); it != mMeshLibrary.end(); ++it)
          delete it->second;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Read bool from text contents of current element
  bool ColladaParser::ReadBoolFromTextContent()
  {
      const char* cur = GetTextContent();
      return (!ASSIMP_strincmp(cur,"true",4) || '0' != *cur);
  }
  
  // ------------------------------------------------------------------------------------------------
  // Read float from text contents of current element
  float ColladaParser::ReadFloatFromTextContent()
  {
      const char* cur = GetTextContent();
      return fast_atof(cur);
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the contents of the file
  void ColladaParser::ReadContents()
  {
      while( mReader->read())
      {
          // handle the root element "COLLADA"
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "COLLADA"))
              {
                  // check for 'version' attribute
                  const int attrib = TestAttribute("version");
                  if (attrib != -1) {
                      const char* version = mReader->getAttributeValue(attrib);
  
                      if (!::strncmp(version,"1.5",3)) {
                          mFormat =  FV_1_5_n;
                          DefaultLogger::get()->debug("Collada schema version is 1.5.n");
                      }
                      else if (!::strncmp(version,"1.4",3)) {
                          mFormat =  FV_1_4_n;
                          DefaultLogger::get()->debug("Collada schema version is 1.4.n");
                      }
                      else if (!::strncmp(version,"1.3",3)) {
                          mFormat =  FV_1_3_n;
                          DefaultLogger::get()->debug("Collada schema version is 1.3.n");
                      }
                  }
  
                  ReadStructure();
              } else
              {
                  DefaultLogger::get()->debug( boost::str( boost::format( "Ignoring global element <%s>.") % mReader->getNodeName()));
                  SkipElement();
              }
          } else
          {
              // skip everything else silently
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the structure of the file
  void ColladaParser::ReadStructure()
  {
      while( mReader->read())
      {
          // beginning of elements
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "asset"))
                  ReadAssetInfo();
              else if( IsElement( "library_animations"))
                  ReadAnimationLibrary();
              else if( IsElement( "library_controllers"))
                  ReadControllerLibrary();
              else if( IsElement( "library_images"))
                  ReadImageLibrary();
              else if( IsElement( "library_materials"))
                  ReadMaterialLibrary();
              else if( IsElement( "library_effects"))
                  ReadEffectLibrary();
              else if( IsElement( "library_geometries"))
                  ReadGeometryLibrary();
              else if( IsElement( "library_visual_scenes"))
                  ReadSceneLibrary();
              else if( IsElement( "library_lights"))
                  ReadLightLibrary();
              else if( IsElement( "library_cameras"))
                  ReadCameraLibrary();
              else if( IsElement( "library_nodes"))
                  ReadSceneNode(NULL); /* some hacking to reuse this piece of code */
              else if( IsElement( "scene"))
                  ReadScene();
              else
                  SkipElement();
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads asset informations such as coordinate system informations and legal blah
  void ColladaParser::ReadAssetInfo()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "unit"))
              {
                  // read unit data from the element's attributes
                  const int attrIndex = TestAttribute( "meter");
                  if (attrIndex == -1) {
                      mUnitSize = 1.f;
                  }
                  else {
                      mUnitSize = mReader->getAttributeValueAsFloat( attrIndex);
                  }
  
                  // consume the trailing stuff
                  if( !mReader->isEmptyElement())
                      SkipElement();
              }
              else if( IsElement( "up_axis"))
              {
                  // read content, strip whitespace, compare
                  const char* content = GetTextContent();
                  if( strncmp( content, "X_UP", 4) == 0)
                      mUpDirection = UP_X;
                  else if( strncmp( content, "Z_UP", 4) == 0)
                      mUpDirection = UP_Z;
                  else
                      mUpDirection = UP_Y;
  
                  // check element end
                  TestClosing( "up_axis");
              } else
              {
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "asset") != 0)
                  ThrowException( "Expected end of <asset> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the animation library
  void ColladaParser::ReadAnimationLibrary()
  {
      if (mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "animation"))
              {
                  // delegate the reading. Depending on the inner elements it will be a container or a anim channel
                  ReadAnimation( &mAnims);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "library_animations") != 0)
                  ThrowException( "Expected end of <library_animations> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an animation into the given parent structure
  void ColladaParser::ReadAnimation( Collada::Animation* pParent)
  {
      if( mReader->isEmptyElement())
          return;
  
      // an <animation> element may be a container for grouping sub-elements or an animation channel
      // this is the channel collection by ID, in case it has channels
      typedef std::map<std::string, AnimationChannel> ChannelMap;
      ChannelMap channels;
      // this is the anim container in case we're a container
      Animation* anim = NULL;
  
      // optional name given as an attribute
      std::string animName;
      int indexName = TestAttribute( "name");
      int indexID = TestAttribute( "id");
      if( indexName >= 0)
          animName = mReader->getAttributeValue( indexName);
      else if( indexID >= 0)
          animName = mReader->getAttributeValue( indexID);
      else
          animName = "animation";
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              // we have subanimations
              if( IsElement( "animation"))
              {
                  // create container from our element
                  if( !anim)
                  {
                      anim = new Animation;
                      anim->mName = animName;
                      pParent->mSubAnims.push_back( anim);
                  }
  
                  // recurse into the subelement
                  ReadAnimation( anim);
              }
              else if( IsElement( "source"))
              {
                  // possible animation data - we'll never know. Better store it
                  ReadSource();
              }
              else if( IsElement( "sampler"))
              {
                  // read the ID to assign the corresponding collada channel afterwards.
                  int indexID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( indexID);
                  ChannelMap::iterator newChannel = channels.insert( std::make_pair( id, AnimationChannel())).first;
  
                  // have it read into a channel
                  ReadAnimationSampler( newChannel->second);
              }
              else if( IsElement( "channel"))
              {
                  // the binding element whose whole purpose is to provide the target to animate
                  // Thanks, Collada! A directly posted information would have been too simple, I guess.
                  // Better add another indirection to that! Can't have enough of those.
                  int indexTarget = GetAttribute( "target");
                  int indexSource = GetAttribute( "source");
                  const char* sourceId = mReader->getAttributeValue( indexSource);
                  if( sourceId[0] == '#')
                      sourceId++;
                  ChannelMap::iterator cit = channels.find( sourceId);
                  if( cit != channels.end())
                      cit->second.mTarget = mReader->getAttributeValue( indexTarget);
  
                  if( !mReader->isEmptyElement())
                      SkipElement();
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "animation") != 0)
                  ThrowException( "Expected end of <animation> element.");
  
              break;
          }
      }
  
      // it turned out to have channels - add them
      if( !channels.empty())
      {
          // special filtering for stupid exporters packing each channel into a separate animation
          if( channels.size() == 1)
          {
              pParent->mChannels.push_back( channels.begin()->second);
          } else
          {
              // else create the animation, if not done yet, and store the channels
              if( !anim)
              {
                  anim = new Animation;
                  anim->mName = animName;
                  pParent->mSubAnims.push_back( anim);
              }
              for( ChannelMap::const_iterator it = channels.begin(); it != channels.end(); ++it)
                  anim->mChannels.push_back( it->second);
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an animation sampler into the given anim channel
  void ColladaParser::ReadAnimationSampler( Collada::AnimationChannel& pChannel)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "input"))
              {
                  int indexSemantic = GetAttribute( "semantic");
                  const char* semantic = mReader->getAttributeValue( indexSemantic);
                  int indexSource = GetAttribute( "source");
                  const char* source = mReader->getAttributeValue( indexSource);
                  if( source[0] != '#')
                      ThrowException( "Unsupported URL format");
                  source++;
  
                  if( strcmp( semantic, "INPUT") == 0)
                      pChannel.mSourceTimes = source;
                  else if( strcmp( semantic, "OUTPUT") == 0)
                      pChannel.mSourceValues = source;
  
                  if( !mReader->isEmptyElement())
                      SkipElement();
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "sampler") != 0)
                  ThrowException( "Expected end of <sampler> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the skeleton controller library
  void ColladaParser::ReadControllerLibrary()
  {
      if (mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "controller"))
              {
                  // read ID. Ask the spec if it's neccessary or optional... you might be surprised.
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  // create an entry and store it in the library under its ID
                  mControllerLibrary[id] = Controller();
  
                  // read on from there
                  ReadController( mControllerLibrary[id]);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "library_controllers") != 0)
                  ThrowException( "Expected end of <library_controllers> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a controller into the given mesh structure
  void ColladaParser::ReadController( Collada::Controller& pController)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              // two types of controllers: "skin" and "morph". Only the first one is relevant, we skip the other
              if( IsElement( "morph"))
              {
                  // should skip everything inside, so there's no danger of catching elements inbetween
                  SkipElement();
              }
              else if( IsElement( "skin"))
              {
                  // read the mesh it refers to. According to the spec this could also be another
                  // controller, but I refuse to implement every single idea they've come up with
                  int sourceIndex = GetAttribute( "source");
                  pController.mMeshId = mReader->getAttributeValue( sourceIndex) + 1;
              }
              else if( IsElement( "bind_shape_matrix"))
              {
                  // content is 16 floats to define a matrix... it seems to be important for some models
            const char* content = GetTextContent();
  
            // read the 16 floats
            for( unsigned int a = 0; a < 16; a++)
            {
                // read a number
            content = fast_atoreal_move<float>( content, pController.mBindShapeMatrix[a]);
                // skip whitespace after it
                SkipSpacesAndLineEnd( &content);
            }
  
          TestClosing( "bind_shape_matrix");
              }
              else if( IsElement( "source"))
              {
                  // data array - we have specialists to handle this
                  ReadSource();
              }
              else if( IsElement( "joints"))
              {
                  ReadControllerJoints( pController);
              }
              else if( IsElement( "vertex_weights"))
              {
                  ReadControllerWeights( pController);
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "controller") == 0)
                  break;
              else if( strcmp( mReader->getNodeName(), "skin") != 0)
                  ThrowException( "Expected end of <controller> element.");
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the joint definitions for the given controller
  void ColladaParser::ReadControllerJoints( Collada::Controller& pController)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              // Input channels for joint data. Two possible semantics: "JOINT" and "INV_BIND_MATRIX"
              if( IsElement( "input"))
              {
                  int indexSemantic = GetAttribute( "semantic");
                  const char* attrSemantic = mReader->getAttributeValue( indexSemantic);
                  int indexSource = GetAttribute( "source");
                  const char* attrSource = mReader->getAttributeValue( indexSource);
  
                  // local URLS always start with a '#'. We don't support global URLs
                  if( attrSource[0] != '#')
                      ThrowException( boost::str( boost::format( "Unsupported URL format in \"%s\" in source attribute of <joints> data <input> element") % attrSource));
                  attrSource++;
  
                  // parse source URL to corresponding source
                  if( strcmp( attrSemantic, "JOINT") == 0)
                      pController.mJointNameSource = attrSource;
                  else if( strcmp( attrSemantic, "INV_BIND_MATRIX") == 0)
                      pController.mJointOffsetMatrixSource = attrSource;
                  else
                      ThrowException( boost::str( boost::format( "Unknown semantic \"%s\" in <joints> data <input> element") % attrSemantic));
  
                  // skip inner data, if present
                  if( !mReader->isEmptyElement())
                      SkipElement();
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "joints") != 0)
                  ThrowException( "Expected end of <joints> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the joint weights for the given controller
  void ColladaParser::ReadControllerWeights( Collada::Controller& pController)
  {
      // read vertex count from attributes and resize the array accordingly
      int indexCount = GetAttribute( "count");
      size_t vertexCount = (size_t) mReader->getAttributeValueAsInt( indexCount);
      pController.mWeightCounts.resize( vertexCount);
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              // Input channels for weight data. Two possible semantics: "JOINT" and "WEIGHT"
              if( IsElement( "input") && vertexCount > 0 )
              {
                  InputChannel channel;
  
                  int indexSemantic = GetAttribute( "semantic");
                  const char* attrSemantic = mReader->getAttributeValue( indexSemantic);
                  int indexSource = GetAttribute( "source");
                  const char* attrSource = mReader->getAttributeValue( indexSource);
                  int indexOffset = TestAttribute( "offset");
                  if( indexOffset >= 0)
                      channel.mOffset = mReader->getAttributeValueAsInt( indexOffset);
  
                  // local URLS always start with a '#'. We don't support global URLs
                  if( attrSource[0] != '#')
                      ThrowException( boost::str( boost::format( "Unsupported URL format in \"%s\" in source attribute of <vertex_weights> data <input> element") % attrSource));
                  channel.mAccessor = attrSource + 1;
  
                  // parse source URL to corresponding source
                  if( strcmp( attrSemantic, "JOINT") == 0)
                      pController.mWeightInputJoints = channel;
                  else if( strcmp( attrSemantic, "WEIGHT") == 0)
                      pController.mWeightInputWeights = channel;
                  else
                      ThrowException( boost::str( boost::format( "Unknown semantic \"%s\" in <vertex_weights> data <input> element") % attrSemantic));
  
                  // skip inner data, if present
                  if( !mReader->isEmptyElement())
                      SkipElement();
              }
              else if( IsElement( "vcount") && vertexCount > 0 )
              {
                  // read weight count per vertex
                  const char* text = GetTextContent();
                  size_t numWeights = 0;
                  for( std::vector<size_t>::iterator it = pController.mWeightCounts.begin(); it != pController.mWeightCounts.end(); ++it)
                  {
                      if( *text == 0)
                          ThrowException( "Out of data while reading <vcount>");
  
                      *it = strtoul10( text, &text);
                      numWeights += *it;
                      SkipSpacesAndLineEnd( &text);
                  }
  
                  TestClosing( "vcount");
  
                  // reserve weight count
                  pController.mWeights.resize( numWeights);
              }
              else if( IsElement( "v") && vertexCount > 0 )
              {
                  // read JointIndex - WeightIndex pairs
                  const char* text = GetTextContent();
  
                  for( std::vector< std::pair<size_t, size_t> >::iterator it = pController.mWeights.begin(); it != pController.mWeights.end(); ++it)
                  {
                      if( *text == 0)
                          ThrowException( "Out of data while reading <vertex_weights>");
                      it->first = strtoul10( text, &text);
                      SkipSpacesAndLineEnd( &text);
                      if( *text == 0)
                          ThrowException( "Out of data while reading <vertex_weights>");
                      it->second = strtoul10( text, &text);
                      SkipSpacesAndLineEnd( &text);
                  }
  
                  TestClosing( "v");
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "vertex_weights") != 0)
                  ThrowException( "Expected end of <vertex_weights> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the image library contents
  void ColladaParser::ReadImageLibrary()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "image"))
              {
                  // read ID. Another entry which is "optional" by design but obligatory in reality
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  // create an entry and store it in the library under its ID
                  mImageLibrary[id] = Image();
  
                  // read on from there
                  ReadImage( mImageLibrary[id]);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "library_images") != 0)
                  ThrowException( "Expected end of <library_images> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an image entry into the given image
  void ColladaParser::ReadImage( Collada::Image& pImage)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT){
              // Need to run different code paths here, depending on the Collada XSD version
              if (IsElement("image")) {
                  SkipElement();
              }
              else if(  IsElement( "init_from"))
              {
                  if (mFormat == FV_1_4_n)
                  {
                      // FIX: C4D exporter writes empty <init_from/> tags
                      if (!mReader->isEmptyElement()) {
                          // element content is filename - hopefully
                          const char* sz = TestTextContent();
                          if (sz)pImage.mFileName = sz;
                          TestClosing( "init_from");
                      }
                      if (!pImage.mFileName.length()) {
                          pImage.mFileName = "unknown_texture";
                      }
                  }
                  else if (mFormat == FV_1_5_n)
                  {
                      // make sure we skip over mip and array initializations, which
                      // we don't support, but which could confuse the loader if
                      // they're not skipped.
                      int attrib = TestAttribute("array_index");
                      if (attrib != -1 && mReader->getAttributeValueAsInt(attrib) > 0) {
                          DefaultLogger::get()->warn("Collada: Ignoring texture array index");
                          continue;
                      }
  
                      attrib = TestAttribute("mip_index");
                      if (attrib != -1 && mReader->getAttributeValueAsInt(attrib) > 0) {
                          DefaultLogger::get()->warn("Collada: Ignoring MIP map layer");
                          continue;
                      }
  
                      // TODO: correctly jump over cube and volume maps?
                  }
              }
              else if (mFormat == FV_1_5_n)
              {
                  if( IsElement( "ref"))
                  {
                      // element content is filename - hopefully
                      const char* sz = TestTextContent();
                      if (sz)pImage.mFileName = sz;
                      TestClosing( "ref");
                  }
                  else if( IsElement( "hex") && !pImage.mFileName.length())
                  {
                      // embedded image. get format
                      const int attrib = TestAttribute("format");
                      if (-1 == attrib)
                          DefaultLogger::get()->warn("Collada: Unknown image file format");
                      else pImage.mEmbeddedFormat = mReader->getAttributeValue(attrib);
  
                      const char* data = GetTextContent();
  
                      // hexadecimal-encoded binary octets. First of all, find the
                      // required buffer size to reserve enough storage.
                      const char* cur = data;
                      while (!IsSpaceOrNewLine(*cur)) cur++;
  
                      const unsigned int size = (unsigned int)(cur-data) * 2;
                      pImage.mImageData.resize(size);
                      for (unsigned int i = 0; i < size;++i)
                          pImage.mImageData[i] = HexOctetToDecimal(data+(i<<1));
  
                      TestClosing( "hex");
                  }
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "image") == 0)
                  break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the material library
  void ColladaParser::ReadMaterialLibrary()
  {
      if( mReader->isEmptyElement())
          return;
  
      std::map<std::string, int> names;
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "material"))
              {
                  // read ID. By now you propably know my opinion about this "specification"
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  std::string name;
                  int attrName = TestAttribute("name");
                  if (attrName >= 0)
                      name = mReader->getAttributeValue( attrName);
  
                  // create an entry and store it in the library under its ID
                  mMaterialLibrary[id] = Material();
  
                  if( !name.empty())
                  {
                      std::map<std::string, int>::iterator it = names.find( name);
                      if( it != names.end())
                      {
                          std::ostringstream strStream;
                          strStream << ++it->second;
                          name.append( " " + strStream.str());
                      }
                      else
                      {
                          names[name] = 0;
                      }
  
                      mMaterialLibrary[id].mName = name;
                  }
  
                  ReadMaterial( mMaterialLibrary[id]);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "library_materials") != 0)
                  ThrowException( "Expected end of <library_materials> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the light library
  void ColladaParser::ReadLightLibrary()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "light"))
              {
                  // read ID. By now you propably know my opinion about this "specification"
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  // create an entry and store it in the library under its ID
                  ReadLight(mLightLibrary[id] = Light());
  
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)    {
              if( strcmp( mReader->getNodeName(), "library_lights") != 0)
                  ThrowException( "Expected end of <library_lights> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the camera library
  void ColladaParser::ReadCameraLibrary()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "camera"))
              {
                  // read ID. By now you propably know my opinion about this "specification"
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  // create an entry and store it in the library under its ID
                  Camera& cam = mCameraLibrary[id];
                  attrID = TestAttribute( "name");
                  if (attrID != -1)
                      cam.mName = mReader->getAttributeValue( attrID);
  
                  ReadCamera(cam);
  
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)    {
              if( strcmp( mReader->getNodeName(), "library_cameras") != 0)
                  ThrowException( "Expected end of <library_cameras> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a material entry into the given material
  void ColladaParser::ReadMaterial( Collada::Material& pMaterial)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if (IsElement("material")) {
                  SkipElement();
              }
              else if( IsElement( "instance_effect"))
              {
                  // referred effect by URL
                  int attrUrl = GetAttribute( "url");
                  const char* url = mReader->getAttributeValue( attrUrl);
                  if( url[0] != '#')
                      ThrowException( "Unknown reference format");
  
                  pMaterial.mEffect = url+1;
  
                  SkipElement();
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "material") != 0)
                  ThrowException( "Expected end of <material> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a light entry into the given light
  void ColladaParser::ReadLight( Collada::Light& pLight)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if (IsElement("light")) {
                  SkipElement();
              }
              else if (IsElement("spot")) {
                  pLight.mType = aiLightSource_SPOT;
              }
              else if (IsElement("ambient")) {
                  pLight.mType = aiLightSource_AMBIENT;
              }
              else if (IsElement("directional")) {
                  pLight.mType = aiLightSource_DIRECTIONAL;
              }
              else if (IsElement("point")) {
                  pLight.mType = aiLightSource_POINT;
              }
              else if (IsElement("color")) {
                  // text content contains 3 floats
                  const char* content = GetTextContent();
  
                  content = fast_atoreal_move<float>( content, (float&)pLight.mColor.r);
                  SkipSpacesAndLineEnd( &content);
  
                  content = fast_atoreal_move<float>( content, (float&)pLight.mColor.g);
                  SkipSpacesAndLineEnd( &content);
  
                  content = fast_atoreal_move<float>( content, (float&)pLight.mColor.b);
                  SkipSpacesAndLineEnd( &content);
  
                  TestClosing( "color");
              }
              else if (IsElement("constant_attenuation")) {
                  pLight.mAttConstant = ReadFloatFromTextContent();
                  TestClosing("constant_attenuation");
              }
              else if (IsElement("linear_attenuation")) {
                  pLight.mAttLinear = ReadFloatFromTextContent();
                  TestClosing("linear_attenuation");
              }
              else if (IsElement("quadratic_attenuation")) {
                  pLight.mAttQuadratic = ReadFloatFromTextContent();
                  TestClosing("quadratic_attenuation");
              }
              else if (IsElement("falloff_angle")) {
                  pLight.mFalloffAngle = ReadFloatFromTextContent();
                  TestClosing("falloff_angle");
              }
              else if (IsElement("falloff_exponent")) {
                  pLight.mFalloffExponent = ReadFloatFromTextContent();
                  TestClosing("falloff_exponent");
              }
              // FCOLLADA extensions
              // -------------------------------------------------------
              else if (IsElement("outer_cone")) {
                  pLight.mOuterAngle = ReadFloatFromTextContent();
                  TestClosing("outer_cone");
              }
              // ... and this one is even deprecated
              else if (IsElement("penumbra_angle")) {
                  pLight.mPenumbraAngle = ReadFloatFromTextContent();
                  TestClosing("penumbra_angle");
              }
              else if (IsElement("intensity")) {
                  pLight.mIntensity = ReadFloatFromTextContent();
                  TestClosing("intensity");
              }
              else if (IsElement("falloff")) {
                  pLight.mOuterAngle = ReadFloatFromTextContent();
                  TestClosing("falloff");
              }
              else if (IsElement("hotspot_beam")) {
                  pLight.mFalloffAngle = ReadFloatFromTextContent();
                  TestClosing("hotspot_beam");
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "light") == 0)
                  break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a camera entry into the given light
  void ColladaParser::ReadCamera( Collada::Camera& pCamera)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if (IsElement("camera")) {
                  SkipElement();
              }
              else if (IsElement("orthographic")) {
                  pCamera.mOrtho = true;
              }
              else if (IsElement("xfov") || IsElement("xmag")) {
                  pCamera.mHorFov = ReadFloatFromTextContent();
                  TestClosing((pCamera.mOrtho ? "xmag" : "xfov"));
              }
              else if (IsElement("yfov") || IsElement("ymag")) {
                  pCamera.mVerFov = ReadFloatFromTextContent();
                  TestClosing((pCamera.mOrtho ? "ymag" : "yfov"));
              }
              else if (IsElement("aspect_ratio")) {
                  pCamera.mAspect = ReadFloatFromTextContent();
                  TestClosing("aspect_ratio");
              }
              else if (IsElement("znear")) {
                  pCamera.mZNear = ReadFloatFromTextContent();
                  TestClosing("znear");
              }
              else if (IsElement("zfar")) {
                  pCamera.mZFar = ReadFloatFromTextContent();
                  TestClosing("zfar");
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "camera") == 0)
                  break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the effect library
  void ColladaParser::ReadEffectLibrary()
  {
      if (mReader->isEmptyElement()) {
          return;
      }
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "effect"))
              {
                  // read ID. Do I have to repeat my ranting about "optional" attributes?
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  // create an entry and store it in the library under its ID
                  mEffectLibrary[id] = Effect();
                  // read on from there
                  ReadEffect( mEffectLibrary[id]);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "library_effects") != 0)
                  ThrowException( "Expected end of <library_effects> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an effect entry into the given effect
  void ColladaParser::ReadEffect( Collada::Effect& pEffect)
  {
      // for the moment we don't support any other type of effect.
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "profile_COMMON"))
                  ReadEffectProfileCommon( pEffect);
              else
                  SkipElement();
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "effect") != 0)
                  ThrowException( "Expected end of <effect> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an COMMON effect profile
  void ColladaParser::ReadEffectProfileCommon( Collada::Effect& pEffect)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "newparam")) {
                  // save ID
                  int attrSID = GetAttribute( "sid");
                  std::string sid = mReader->getAttributeValue( attrSID);
                  pEffect.mParams[sid] = EffectParam();
                  ReadEffectParam( pEffect.mParams[sid]);
              }
              else if( IsElement( "technique") || IsElement( "extra"))
              {
                  // just syntactic sugar
              }
  
              else if( mFormat == FV_1_4_n && IsElement( "image"))
              {
                  // read ID. Another entry which is "optional" by design but obligatory in reality
                  int attrID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( attrID);
  
                  // create an entry and store it in the library under its ID
                  mImageLibrary[id] = Image();
  
                  // read on from there
                  ReadImage( mImageLibrary[id]);
              }
  
              /* Shading modes */
              else if( IsElement( "phong"))
                  pEffect.mShadeType = Shade_Phong;
              else if( IsElement( "constant"))
                  pEffect.mShadeType = Shade_Constant;
              else if( IsElement( "lambert"))
                  pEffect.mShadeType = Shade_Lambert;
              else if( IsElement( "blinn"))
                  pEffect.mShadeType = Shade_Blinn;
  
              /* Color + texture properties */
              else if( IsElement( "emission"))
                  ReadEffectColor( pEffect.mEmissive, pEffect.mTexEmissive);
              else if( IsElement( "ambient"))
                  ReadEffectColor( pEffect.mAmbient, pEffect.mTexAmbient);
              else if( IsElement( "diffuse"))
                  ReadEffectColor( pEffect.mDiffuse, pEffect.mTexDiffuse);
              else if( IsElement( "specular"))
                  ReadEffectColor( pEffect.mSpecular, pEffect.mTexSpecular);
              else if( IsElement( "reflective")) {
                  ReadEffectColor( pEffect.mReflective, pEffect.mTexReflective);
              }
              else if( IsElement( "transparent")) {
                  pEffect.mHasTransparency = true;
  
                  // In RGB_ZERO mode, the transparency is interpreted in reverse, go figure...
                  if(::strcmp(mReader->getAttributeValueSafe("opaque"), "RGB_ZERO") == 0) {
                      // TODO: handle RGB_ZERO mode completely
                      pEffect.mRGBTransparency = true;
                  }
  
                  ReadEffectColor( pEffect.mTransparent,pEffect.mTexTransparent);
              }
              else if( IsElement( "shininess"))
                  ReadEffectFloat( pEffect.mShininess);
              else if( IsElement( "reflectivity"))
                  ReadEffectFloat( pEffect.mReflectivity);
  
              /* Single scalar properties */
              else if( IsElement( "transparency"))
                  ReadEffectFloat( pEffect.mTransparency);
              else if( IsElement( "index_of_refraction"))
                  ReadEffectFloat( pEffect.mRefractIndex);
  
              // GOOGLEEARTH/OKINO extensions
              // -------------------------------------------------------
              else if( IsElement( "double_sided"))
                  pEffect.mDoubleSided = ReadBoolFromTextContent();
  
              // FCOLLADA extensions
              // -------------------------------------------------------
              else if( IsElement( "bump")) {
                  aiColor4D dummy;
                  ReadEffectColor( dummy,pEffect.mTexBump);
              }
  
              // MAX3D extensions
              // -------------------------------------------------------
              else if( IsElement( "wireframe"))   {
                  pEffect.mWireframe = ReadBoolFromTextContent();
                  TestClosing( "wireframe");
              }
              else if( IsElement( "faceted")) {
                  pEffect.mFaceted = ReadBoolFromTextContent();
                  TestClosing( "faceted");
              }
              else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "profile_COMMON") == 0)
              {
                  break;
              }
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Read texture wrapping + UV transform settings from a profile==Maya chunk
  void ColladaParser::ReadSamplerProperties( Sampler& out )
  {
      if (mReader->isEmptyElement()) {
          return;
      }
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
  
              // MAYA extensions
              // -------------------------------------------------------
              if( IsElement( "wrapU"))        {
                  out.mWrapU = ReadBoolFromTextContent();
                  TestClosing( "wrapU");
              }
              else if( IsElement( "wrapV"))   {
                  out.mWrapV = ReadBoolFromTextContent();
                  TestClosing( "wrapV");
              }
              else if( IsElement( "mirrorU"))     {
                  out.mMirrorU = ReadBoolFromTextContent();
                  TestClosing( "mirrorU");
              }
              else if( IsElement( "mirrorV")) {
                  out.mMirrorV = ReadBoolFromTextContent();
                  TestClosing( "mirrorV");
              }
              else if( IsElement( "repeatU")) {
                  out.mTransform.mScaling.x = ReadFloatFromTextContent();
                  TestClosing( "repeatU");
              }
              else if( IsElement( "repeatV")) {
                  out.mTransform.mScaling.y = ReadFloatFromTextContent();
                  TestClosing( "repeatV");
              }
              else if( IsElement( "offsetU")) {
                  out.mTransform.mTranslation.x = ReadFloatFromTextContent();
                  TestClosing( "offsetU");
              }
              else if( IsElement( "offsetV")) {
                  out.mTransform.mTranslation.y = ReadFloatFromTextContent();
                  TestClosing( "offsetV");
              }
              else if( IsElement( "rotateUV"))    {
                  out.mTransform.mRotation = ReadFloatFromTextContent();
                  TestClosing( "rotateUV");
              }
              else if( IsElement( "blend_mode"))  {
  
                  const char* sz = GetTextContent();
                  // http://www.feelingsoftware.com/content/view/55/72/lang,en/
                  // NONE, OVER, IN, OUT, ADD, SUBTRACT, MULTIPLY, DIFFERENCE, LIGHTEN, DARKEN, SATURATE, DESATURATE and ILLUMINATE
                  if (0 == ASSIMP_strincmp(sz,"ADD",3))
                      out.mOp = aiTextureOp_Add;
  
                  else if (0 == ASSIMP_strincmp(sz,"SUBTRACT",8))
                      out.mOp = aiTextureOp_Subtract;
  
                  else if (0 == ASSIMP_strincmp(sz,"MULTIPLY",8))
                      out.mOp = aiTextureOp_Multiply;
  
                  else  {
                      DefaultLogger::get()->warn("Collada: Unsupported MAYA texture blend mode");
                  }
                  TestClosing( "blend_mode");
              }
              // OKINO extensions
              // -------------------------------------------------------
              else if( IsElement( "weighting"))   {
                  out.mWeighting = ReadFloatFromTextContent();
                  TestClosing( "weighting");
              }
              else if( IsElement( "mix_with_previous_layer")) {
                  out.mMixWithPrevious = ReadFloatFromTextContent();
                  TestClosing( "mix_with_previous_layer");
              }
              // MAX3D extensions
              // -------------------------------------------------------
              else if( IsElement( "amount"))  {
                  out.mWeighting = ReadFloatFromTextContent();
                  TestClosing( "amount");
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              if( strcmp( mReader->getNodeName(), "technique") == 0)
                  break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an effect entry containing a color or a texture defining that color
  void ColladaParser::ReadEffectColor( aiColor4D& pColor, Sampler& pSampler)
  {
      if (mReader->isEmptyElement())
          return;
  
      // Save current element name
      const std::string curElem = mReader->getNodeName();
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "color"))
              {
                  // text content contains 4 floats
                  const char* content = GetTextContent();
  
                  content = fast_atoreal_move<float>( content, (float&)pColor.r);
                  SkipSpacesAndLineEnd( &content);
  
                  content = fast_atoreal_move<float>( content, (float&)pColor.g);
                  SkipSpacesAndLineEnd( &content);
  
                  content = fast_atoreal_move<float>( content, (float&)pColor.b);
                  SkipSpacesAndLineEnd( &content);
  
                  content = fast_atoreal_move<float>( content, (float&)pColor.a);
                  SkipSpacesAndLineEnd( &content);
                  TestClosing( "color");
              }
              else if( IsElement( "texture"))
              {
                  // get name of source textur/sampler
                  int attrTex = GetAttribute( "texture");
                  pSampler.mName = mReader->getAttributeValue( attrTex);
  
                  // get name of UV source channel. Specification demands it to be there, but some exporters
                  // don't write it. It will be the default UV channel in case it's missing.
                  attrTex = TestAttribute( "texcoord");
                  if( attrTex >= 0 )
                      pSampler.mUVChannel = mReader->getAttributeValue( attrTex);
                  //SkipElement();
  
                  // as we've read texture, the color needs to be 1,1,1,1
                  pColor = aiColor4D(1.f, 1.f, 1.f, 1.f);
              }
              else if( IsElement( "technique"))
              {
                  const int _profile = GetAttribute( "profile");
                  const char* profile = mReader->getAttributeValue( _profile );
  
                  // Some extensions are quite useful ... ReadSamplerProperties processes
                  // several extensions in MAYA, OKINO and MAX3D profiles.
                  if (!::strcmp(profile,"MAYA") || !::strcmp(profile,"MAX3D") || !::strcmp(profile,"OKINO"))
                  {
                      // get more information on this sampler
                      ReadSamplerProperties(pSampler);
                  }
                  else SkipElement();
              }
              else if( !IsElement( "extra"))
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END){
              if (mReader->getNodeName() == curElem)
                  break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an effect entry containing a float
  void ColladaParser::ReadEffectFloat( float& pFloat)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT){
              if( IsElement( "float"))
              {
                  // text content contains a single floats
                  const char* content = GetTextContent();
                  content = fast_atoreal_move<float>( content, pFloat);
                  SkipSpacesAndLineEnd( &content);
  
                  TestClosing( "float");
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END){
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an effect parameter specification of any kind
  void ColladaParser::ReadEffectParam( Collada::EffectParam& pParam)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "surface"))
              {
                  // image ID given inside <init_from> tags
                  TestOpening( "init_from");
                  const char* content = GetTextContent();
                  pParam.mType = Param_Surface;
                  pParam.mReference = content;
                  TestClosing( "init_from");
  
                  // don't care for remaining stuff
                  SkipElement( "surface");
              }
              else if( IsElement( "sampler2D"))
              {
                  // surface ID is given inside <source> tags
                  TestOpening( "source");
                  const char* content = GetTextContent();
                  pParam.mType = Param_Sampler;
                  pParam.mReference = content;
                  TestClosing( "source");
  
                  // don't care for remaining stuff
                  SkipElement( "sampler2D");
              } else
              {
                  // ignore unknown element
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the geometry library contents
  void ColladaParser::ReadGeometryLibrary()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "geometry"))
              {
                  // read ID. Another entry which is "optional" by design but obligatory in reality
                  int indexID = GetAttribute( "id");
                  std::string id = mReader->getAttributeValue( indexID);
  
                  // TODO: (thom) support SIDs
                  // ai_assert( TestAttribute( "sid") == -1);
  
                  // create a mesh and store it in the library under its ID
                  Mesh* mesh = new Mesh;
                  mMeshLibrary[id] = mesh;
  
                  // read the mesh name if it exists
                  const int nameIndex = TestAttribute("name");
                  if(nameIndex != -1)
                  {
                      mesh->mName = mReader->getAttributeValue(nameIndex);
                  }
  
                  // read on from there
                  ReadGeometry( mesh);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "library_geometries") != 0)
                  ThrowException( "Expected end of <library_geometries> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a geometry from the geometry library.
  void ColladaParser::ReadGeometry( Collada::Mesh* pMesh)
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "mesh"))
              {
                  // read on from there
                  ReadMesh( pMesh);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "geometry") != 0)
                  ThrowException( "Expected end of <geometry> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a mesh from the geometry library
  void ColladaParser::ReadMesh( Mesh* pMesh)
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "source"))
              {
                  // we have professionals dealing with this
                  ReadSource();
              }
              else if( IsElement( "vertices"))
              {
                  // read per-vertex mesh data
                  ReadVertexData( pMesh);
              }
              else if( IsElement( "triangles") || IsElement( "lines") || IsElement( "linestrips")
                  || IsElement( "polygons") || IsElement( "polylist") || IsElement( "trifans") || IsElement( "tristrips"))
              {
                  // read per-index mesh data and faces setup
                  ReadIndexData( pMesh);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "technique_common") == 0)
              {
                  // end of another meaningless element - read over it
              }
              else if( strcmp( mReader->getNodeName(), "mesh") == 0)
              {
                  // end of <mesh> element - we're done here
                  break;
              } else
              {
                  // everything else should be punished
                  ThrowException( "Expected end of <mesh> element.");
              }
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a source element
  void ColladaParser::ReadSource()
  {
      int indexID = GetAttribute( "id");
      std::string sourceID = mReader->getAttributeValue( indexID);
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "float_array") || IsElement( "IDREF_array") || IsElement( "Name_array"))
              {
                  ReadDataArray();
              }
              else if( IsElement( "technique_common"))
              {
                  // I don't care for your profiles
              }
              else if( IsElement( "accessor"))
              {
                  ReadAccessor( sourceID);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "source") == 0)
              {
                  // end of <source> - we're done
                  break;
              }
              else if( strcmp( mReader->getNodeName(), "technique_common") == 0)
              {
                  // end of another meaningless element - read over it
              } else
              {
                  // everything else should be punished
                  ThrowException( "Expected end of <source> element.");
              }
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a data array holding a number of floats, and stores it in the global library
  void ColladaParser::ReadDataArray()
  {
      std::string elmName = mReader->getNodeName();
      bool isStringArray = (elmName == "IDREF_array" || elmName == "Name_array");
    bool isEmptyElement = mReader->isEmptyElement();
  
      // read attributes
      int indexID = GetAttribute( "id");
      std::string id = mReader->getAttributeValue( indexID);
      int indexCount = GetAttribute( "count");
      unsigned int count = (unsigned int) mReader->getAttributeValueAsInt( indexCount);
      const char* content = TestTextContent();
  
    // read values and store inside an array in the data library
    mDataLibrary[id] = Data();
    Data& data = mDataLibrary[id];
    data.mIsStringArray = isStringArray;
  
    // some exporters write empty data arrays, but we need to conserve them anyways because others might reference them
    if (content)
    {
          if( isStringArray)
          {
              data.mStrings.reserve( count);
              std::string s;
  
              for( unsigned int a = 0; a < count; a++)
              {
                  if( *content == 0)
                      ThrowException( "Expected more values while reading IDREF_array contents.");
  
                  s.clear();
                  while( !IsSpaceOrNewLine( *content))
                      s += *content++;
                  data.mStrings.push_back( s);
  
                  SkipSpacesAndLineEnd( &content);
              }
          } else
          {
              data.mValues.reserve( count);
  
              for( unsigned int a = 0; a < count; a++)
              {
                  if( *content == 0)
                      ThrowException( "Expected more values while reading float_array contents.");
  
                  float value;
                  // read a number
                  content = fast_atoreal_move<float>( content, value);
                  data.mValues.push_back( value);
                  // skip whitespace after it
                  SkipSpacesAndLineEnd( &content);
              }
          }
      }
  
    // test for closing tag
    if( !isEmptyElement )
      TestClosing( elmName.c_str());
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads an accessor and stores it in the global library
  void ColladaParser::ReadAccessor( const std::string& pID)
  {
      // read accessor attributes
      int attrSource = GetAttribute( "source");
      const char* source = mReader->getAttributeValue( attrSource);
      if( source[0] != '#')
          ThrowException( boost::str( boost::format( "Unknown reference format in url \"%s\" in source attribute of <accessor> element.") % source));
      int attrCount = GetAttribute( "count");
      unsigned int count = (unsigned int) mReader->getAttributeValueAsInt( attrCount);
      int attrOffset = TestAttribute( "offset");
      unsigned int offset = 0;
      if( attrOffset > -1)
          offset = (unsigned int) mReader->getAttributeValueAsInt( attrOffset);
      int attrStride = TestAttribute( "stride");
      unsigned int stride = 1;
      if( attrStride > -1)
          stride = (unsigned int) mReader->getAttributeValueAsInt( attrStride);
  
      // store in the library under the given ID
      mAccessorLibrary[pID] = Accessor();
      Accessor& acc = mAccessorLibrary[pID];
      acc.mCount = count;
      acc.mOffset = offset;
      acc.mStride = stride;
      acc.mSource = source+1; // ignore the leading '#'
      acc.mSize = 0; // gets incremented with every param
  
      // and read the components
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "param"))
              {
                  // read data param
                  int attrName = TestAttribute( "name");
                  std::string name;
                  if( attrName > -1)
                  {
                      name = mReader->getAttributeValue( attrName);
  
                      // analyse for common type components and store it's sub-offset in the corresponding field
  
                      /* Cartesian coordinates */
                      if( name == "X") acc.mSubOffset[0] = acc.mParams.size();
                      else if( name == "Y") acc.mSubOffset[1] = acc.mParams.size();
                      else if( name == "Z") acc.mSubOffset[2] = acc.mParams.size();
  
                      /* RGBA colors */
                      else if( name == "R") acc.mSubOffset[0] = acc.mParams.size();
                      else if( name == "G") acc.mSubOffset[1] = acc.mParams.size();
                      else if( name == "B") acc.mSubOffset[2] = acc.mParams.size();
                      else if( name == "A") acc.mSubOffset[3] = acc.mParams.size();
  
                      /* UVWQ (STPQ) texture coordinates */
                      else if( name == "S") acc.mSubOffset[0] = acc.mParams.size();
                      else if( name == "T") acc.mSubOffset[1] = acc.mParams.size();
                      else if( name == "P") acc.mSubOffset[2] = acc.mParams.size();
                  //  else if( name == "Q") acc.mSubOffset[3] = acc.mParams.size();
                      /* 4D uv coordinates are not supported in Assimp */
  
                      /* Generic extra data, interpreted as UV data, too*/
                      else if( name == "U") acc.mSubOffset[0] = acc.mParams.size();
                      else if( name == "V") acc.mSubOffset[1] = acc.mParams.size();
                      //else
                      //  DefaultLogger::get()->warn( boost::str( boost::format( "Unknown accessor parameter \"%s\". Ignoring data channel.") % name));
                  }
  
                  // read data type
                  int attrType = TestAttribute( "type");
                  if( attrType > -1)
                  {
                      // for the moment we only distinguish between a 4x4 matrix and anything else.
                      // TODO: (thom) I don't have a spec here at work. Check if there are other multi-value types
                      // which should be tested for here.
                      std::string type = mReader->getAttributeValue( attrType);
                      if( type == "float4x4")
                          acc.mSize += 16;
                      else
                          acc.mSize += 1;
                  }
  
                  acc.mParams.push_back( name);
  
                  // skip remaining stuff of this element, if any
                  SkipElement();
              } else
              {
                  ThrowException( boost::str( boost::format( "Unexpected sub element <%s> in tag <accessor>") % mReader->getNodeName()));
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "accessor") != 0)
                  ThrowException( "Expected end of <accessor> element.");
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads input declarations of per-vertex mesh data into the given mesh
  void ColladaParser::ReadVertexData( Mesh* pMesh)
  {
      // extract the ID of the <vertices> element. Not that we care, but to catch strange referencing schemes we should warn about
      int attrID= GetAttribute( "id");
      pMesh->mVertexID = mReader->getAttributeValue( attrID);
  
      // a number of <input> elements
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "input"))
              {
                  ReadInputChannel( pMesh->mPerVertexData);
              } else
              {
                  ThrowException( boost::str( boost::format( "Unexpected sub element <%s> in tag <vertices>") % mReader->getNodeName()));
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "vertices") != 0)
                  ThrowException( "Expected end of <vertices> element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads input declarations of per-index mesh data into the given mesh
  void ColladaParser::ReadIndexData( Mesh* pMesh)
  {
      std::vector<size_t> vcount;
      std::vector<InputChannel> perIndexData;
  
      // read primitive count from the attribute
      int attrCount = GetAttribute( "count");
      size_t numPrimitives = (size_t) mReader->getAttributeValueAsInt( attrCount);
      // some mesh types (e.g. tristrips) don't specify primitive count upfront,
      // so we need to sum up the actual number of primitives while we read the <p>-tags
      size_t actualPrimitives = 0;
  
      // material subgroup
      int attrMaterial = TestAttribute( "material");
      SubMesh subgroup;
      if( attrMaterial > -1)
          subgroup.mMaterial = mReader->getAttributeValue( attrMaterial);
  
      // distinguish between polys and triangles
      std::string elementName = mReader->getNodeName();
      PrimitiveType primType = Prim_Invalid;
      if( IsElement( "lines"))
          primType = Prim_Lines;
      else if( IsElement( "linestrips"))
          primType = Prim_LineStrip;
      else if( IsElement( "polygons"))
          primType = Prim_Polygon;
      else if( IsElement( "polylist"))
          primType = Prim_Polylist;
      else if( IsElement( "triangles"))
          primType = Prim_Triangles;
      else if( IsElement( "trifans"))
          primType = Prim_TriFans;
      else if( IsElement( "tristrips"))
          primType = Prim_TriStrips;
  
      ai_assert( primType != Prim_Invalid);
  
      // also a number of <input> elements, but in addition a <p> primitive collection and propably index counts for all primitives
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "input"))
              {
                  ReadInputChannel( perIndexData);
              }
              else if( IsElement( "vcount"))
              {
                  if( !mReader->isEmptyElement())
                  {
                      if (numPrimitives)  // It is possible to define a mesh without any primitives
                      {
                          // case <polylist> - specifies the number of indices for each polygon
                          const char* content = GetTextContent();
                          vcount.reserve( numPrimitives);
                          for( unsigned int a = 0; a < numPrimitives; a++)
                          {
                              if( *content == 0)
                                  ThrowException( "Expected more values while reading <vcount> contents.");
                              // read a number
                              vcount.push_back( (size_t) strtoul10( content, &content));
                              // skip whitespace after it
                              SkipSpacesAndLineEnd( &content);
                          }
                      }
  
                      TestClosing( "vcount");
                  }
              }
              else if( IsElement( "p"))
              {
                  if( !mReader->isEmptyElement())
                  {
                      // now here the actual fun starts - these are the indices to construct the mesh data from
                      actualPrimitives += ReadPrimitives(pMesh, perIndexData, numPrimitives, vcount, primType);
                  }
              }
              else if (IsElement("extra"))
              {
                  SkipElement("extra");
              } else
              {
                  ThrowException( boost::str( boost::format( "Unexpected sub element <%s> in tag <%s>") % mReader->getNodeName() % elementName));
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( mReader->getNodeName() != elementName)
                  ThrowException( boost::str( boost::format( "Expected end of <%s> element.") % elementName));
  
              break;
          }
      }
  
  #ifdef ASSIMP_BUILD_DEBUG
      if (primType != Prim_TriFans && primType != Prim_TriStrips) {
          ai_assert(actualPrimitives == numPrimitives);
      }
  #endif
  
      // only when we're done reading all <p> tags (and thus know the final vertex count) can we commit the submesh
      subgroup.mNumFaces = actualPrimitives;
      pMesh->mSubMeshes.push_back(subgroup);
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a single input channel element and stores it in the given array, if valid
  void ColladaParser::ReadInputChannel( std::vector<InputChannel>& poChannels)
  {
      InputChannel channel;
  
      // read semantic
      int attrSemantic = GetAttribute( "semantic");
      std::string semantic = mReader->getAttributeValue( attrSemantic);
      channel.mType = GetTypeForSemantic( semantic);
  
      // read source
      int attrSource = GetAttribute( "source");
      const char* source = mReader->getAttributeValue( attrSource);
      if( source[0] != '#')
          ThrowException( boost::str( boost::format( "Unknown reference format in url \"%s\" in source attribute of <input> element.") % source));
      channel.mAccessor = source+1; // skipping the leading #, hopefully the remaining text is the accessor ID only
  
      // read index offset, if per-index <input>
      int attrOffset = TestAttribute( "offset");
      if( attrOffset > -1)
          channel.mOffset = mReader->getAttributeValueAsInt( attrOffset);
  
      // read set if texture coordinates
      if(channel.mType == IT_Texcoord || channel.mType == IT_Color){
          int attrSet = TestAttribute("set");
          if(attrSet > -1){
              attrSet = mReader->getAttributeValueAsInt( attrSet);
              if(attrSet < 0)
                  ThrowException( boost::str( boost::format( "Invalid index \"%i\" in set attribute of <input> element") % (attrSet)));
  
              channel.mIndex = attrSet;
          }
      }
  
      // store, if valid type
      if( channel.mType != IT_Invalid)
          poChannels.push_back( channel);
  
      // skip remaining stuff of this element, if any
      SkipElement();
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a <p> primitive index list and assembles the mesh data into the given mesh
  size_t ColladaParser::ReadPrimitives( Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels,
      size_t pNumPrimitives, const std::vector<size_t>& pVCount, PrimitiveType pPrimType)
  {
      // determine number of indices coming per vertex
      // find the offset index for all per-vertex channels
      size_t numOffsets = 1;
      size_t perVertexOffset = SIZE_MAX; // invalid value
      BOOST_FOREACH( const InputChannel& channel, pPerIndexChannels)
      {
          numOffsets = std::max( numOffsets, channel.mOffset+1);
          if( channel.mType == IT_Vertex)
              perVertexOffset = channel.mOffset;
      }
  
      // determine the expected number of indices
      size_t expectedPointCount = 0;
      switch( pPrimType)
      {
          case Prim_Polylist:
          {
              BOOST_FOREACH( size_t i, pVCount)
                  expectedPointCount += i;
              break;
          }
          case Prim_Lines:
              expectedPointCount = 2 * pNumPrimitives;
              break;
          case Prim_Triangles:
              expectedPointCount = 3 * pNumPrimitives;
              break;
          default:
              // other primitive types don't state the index count upfront... we need to guess
              break;
      }
  
      // and read all indices into a temporary array
      std::vector<size_t> indices;
      if( expectedPointCount > 0)
          indices.reserve( expectedPointCount * numOffsets);
  
      if (pNumPrimitives > 0) // It is possible to not contain any indicies
      {
          const char* content = GetTextContent();
          while( *content != 0)
          {
              // read a value.
              // Hack: (thom) Some exporters put negative indices sometimes. We just try to carry on anyways.
              int value = std::max( 0, strtol10( content, &content));
              indices.push_back( size_t( value));
              // skip whitespace after it
              SkipSpacesAndLineEnd( &content);
          }
      }
  
      // complain if the index count doesn't fit
      if( expectedPointCount > 0 && indices.size() != expectedPointCount * numOffsets)
          ThrowException( "Expected different index count in <p> element.");
      else if( expectedPointCount == 0 && (indices.size() % numOffsets) != 0)
          ThrowException( "Expected different index count in <p> element.");
  
      // find the data for all sources
    for( std::vector<InputChannel>::iterator it = pMesh->mPerVertexData.begin(); it != pMesh->mPerVertexData.end(); ++it)
      {
      InputChannel& input = *it;
          if( input.mResolved)
              continue;
  
          // find accessor
          input.mResolved = &ResolveLibraryReference( mAccessorLibrary, input.mAccessor);
          // resolve accessor's data pointer as well, if neccessary
          const Accessor* acc = input.mResolved;
          if( !acc->mData)
              acc->mData = &ResolveLibraryReference( mDataLibrary, acc->mSource);
      }
      // and the same for the per-index channels
    for( std::vector<InputChannel>::iterator it = pPerIndexChannels.begin(); it != pPerIndexChannels.end(); ++it)
    {
      InputChannel& input = *it;
          if( input.mResolved)
              continue;
  
          // ignore vertex pointer, it doesn't refer to an accessor
          if( input.mType == IT_Vertex)
          {
              // warn if the vertex channel does not refer to the <vertices> element in the same mesh
              if( input.mAccessor != pMesh->mVertexID)
                  ThrowException( "Unsupported vertex referencing scheme.");
              continue;
          }
  
          // find accessor
          input.mResolved = &ResolveLibraryReference( mAccessorLibrary, input.mAccessor);
          // resolve accessor's data pointer as well, if neccessary
          const Accessor* acc = input.mResolved;
          if( !acc->mData)
              acc->mData = &ResolveLibraryReference( mDataLibrary, acc->mSource);
      }
  
      // For continued primitives, the given count does not come all in one <p>, but only one primitive per <p>
      size_t numPrimitives = pNumPrimitives;
      if( pPrimType == Prim_TriFans || pPrimType == Prim_Polygon)
          numPrimitives = 1;
      // For continued primitives, the given count is actually the number of <p>'s inside the parent tag
      if ( pPrimType == Prim_TriStrips){
          size_t numberOfVertices = indices.size() / numOffsets;
          numPrimitives = numberOfVertices - 2;
      }
  
      pMesh->mFaceSize.reserve( numPrimitives);
      pMesh->mFacePosIndices.reserve( indices.size() / numOffsets);
  
      size_t polylistStartVertex = 0;
      for (size_t currentPrimitive = 0; currentPrimitive < numPrimitives; currentPrimitive++)
      {
          // determine number of points for this primitive
          size_t numPoints = 0;
          switch( pPrimType)
          {
              case Prim_Lines:
                  numPoints = 2;
                  for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
                      CopyVertex(currentVertex, numOffsets, numPoints, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
                  break;
              case Prim_Triangles:
                  numPoints = 3;
                  for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
                      CopyVertex(currentVertex, numOffsets, numPoints, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
                  break;
              case Prim_TriStrips:
                  numPoints = 3;
                  ReadPrimTriStrips(numOffsets, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
                  break;
              case Prim_Polylist:
                  numPoints = pVCount[currentPrimitive];
                  for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
                      CopyVertex(polylistStartVertex + currentVertex, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, 0, indices);
                  polylistStartVertex += numPoints;
                  break;
              case Prim_TriFans:
              case Prim_Polygon:
                  numPoints = indices.size() / numOffsets;
                  for (size_t currentVertex = 0; currentVertex < numPoints; currentVertex++)
                      CopyVertex(currentVertex, numOffsets, numPoints, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
                  break;
              default:
                  // LineStrip is not supported due to expected index unmangling
                  ThrowException( "Unsupported primitive type.");
                  break;
          }
  
          // store the face size to later reconstruct the face from
          pMesh->mFaceSize.push_back( numPoints);
      }
  
      // if I ever get my hands on that guy who invented this steaming pile of indirection...
      TestClosing( "p");
      return numPrimitives;
  }
  
  void ColladaParser::CopyVertex(size_t currentVertex, size_t numOffsets, size_t numPoints, size_t perVertexOffset, Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels, size_t currentPrimitive, const std::vector<size_t>& indices){
      // calculate the base offset of the vertex whose attributes we ant to copy
      size_t baseOffset = currentPrimitive * numOffsets * numPoints + currentVertex * numOffsets;
  
      // don't overrun the boundaries of the index list
      size_t maxIndexRequested = baseOffset + numOffsets - 1;
      ai_assert(maxIndexRequested < indices.size());
  
      // extract per-vertex channels using the global per-vertex offset
      for (std::vector<InputChannel>::iterator it = pMesh->mPerVertexData.begin(); it != pMesh->mPerVertexData.end(); ++it)
          ExtractDataObjectFromChannel(*it, indices[baseOffset + perVertexOffset], pMesh);
      // and extract per-index channels using there specified offset
      for (std::vector<InputChannel>::iterator it = pPerIndexChannels.begin(); it != pPerIndexChannels.end(); ++it)
          ExtractDataObjectFromChannel(*it, indices[baseOffset + it->mOffset], pMesh);
  
      // store the vertex-data index for later assignment of bone vertex weights
      pMesh->mFacePosIndices.push_back(indices[baseOffset + perVertexOffset]);
  }
  
  void ColladaParser::ReadPrimTriStrips(size_t numOffsets, size_t perVertexOffset, Mesh* pMesh, std::vector<InputChannel>& pPerIndexChannels, size_t currentPrimitive, const std::vector<size_t>& indices){
      if (currentPrimitive % 2 != 0){
          //odd tristrip triangles need their indices mangled, to preserve winding direction
          CopyVertex(1, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
          CopyVertex(0, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
          CopyVertex(2, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
      }
      else {//for non tristrips or even tristrip triangles
          CopyVertex(0, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
          CopyVertex(1, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
          CopyVertex(2, numOffsets, 1, perVertexOffset, pMesh, pPerIndexChannels, currentPrimitive, indices);
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Extracts a single object from an input channel and stores it in the appropriate mesh data array
  void ColladaParser::ExtractDataObjectFromChannel( const InputChannel& pInput, size_t pLocalIndex, Mesh* pMesh)
  {
      // ignore vertex referrer - we handle them that separate
      if( pInput.mType == IT_Vertex)
          return;
  
      const Accessor& acc = *pInput.mResolved;
      if( pLocalIndex >= acc.mCount)
          ThrowException( boost::str( boost::format( "Invalid data index (%d/%d) in primitive specification") % pLocalIndex % acc.mCount));
  
      // get a pointer to the start of the data object referred to by the accessor and the local index
      const float* dataObject = &(acc.mData->mValues[0]) + acc.mOffset + pLocalIndex* acc.mStride;
  
      // assemble according to the accessors component sub-offset list. We don't care, yet,
      // what kind of object exactly we're extracting here
      float obj[4];
      for( size_t c = 0; c < 4; ++c)
          obj[c] = dataObject[acc.mSubOffset[c]];
  
      // now we reinterpret it according to the type we're reading here
      switch( pInput.mType)
      {
          case IT_Position: // ignore all position streams except 0 - there can be only one position
              if( pInput.mIndex == 0)
                  pMesh->mPositions.push_back( aiVector3D( obj[0], obj[1], obj[2]));
              else
                  DefaultLogger::get()->error("Collada: just one vertex position stream supported");
              break;
          case IT_Normal:
              // pad to current vertex count if necessary
              if( pMesh->mNormals.size() < pMesh->mPositions.size()-1)
                  pMesh->mNormals.insert( pMesh->mNormals.end(), pMesh->mPositions.size() - pMesh->mNormals.size() - 1, aiVector3D( 0, 1, 0));
  
              // ignore all normal streams except 0 - there can be only one normal
              if( pInput.mIndex == 0)
                  pMesh->mNormals.push_back( aiVector3D( obj[0], obj[1], obj[2]));
              else
                  DefaultLogger::get()->error("Collada: just one vertex normal stream supported");
              break;
          case IT_Tangent:
              // pad to current vertex count if necessary
              if( pMesh->mTangents.size() < pMesh->mPositions.size()-1)
                  pMesh->mTangents.insert( pMesh->mTangents.end(), pMesh->mPositions.size() - pMesh->mTangents.size() - 1, aiVector3D( 1, 0, 0));
  
              // ignore all tangent streams except 0 - there can be only one tangent
              if( pInput.mIndex == 0)
                  pMesh->mTangents.push_back( aiVector3D( obj[0], obj[1], obj[2]));
              else
                  DefaultLogger::get()->error("Collada: just one vertex tangent stream supported");
              break;
          case IT_Bitangent:
              // pad to current vertex count if necessary
              if( pMesh->mBitangents.size() < pMesh->mPositions.size()-1)
                  pMesh->mBitangents.insert( pMesh->mBitangents.end(), pMesh->mPositions.size() - pMesh->mBitangents.size() - 1, aiVector3D( 0, 0, 1));
  
              // ignore all bitangent streams except 0 - there can be only one bitangent
              if( pInput.mIndex == 0)
                  pMesh->mBitangents.push_back( aiVector3D( obj[0], obj[1], obj[2]));
              else
                  DefaultLogger::get()->error("Collada: just one vertex bitangent stream supported");
              break;
          case IT_Texcoord:
              // up to 4 texture coord sets are fine, ignore the others
              if( pInput.mIndex < AI_MAX_NUMBER_OF_TEXTURECOORDS)
              {
                  // pad to current vertex count if necessary
                  if( pMesh->mTexCoords[pInput.mIndex].size() < pMesh->mPositions.size()-1)
                      pMesh->mTexCoords[pInput.mIndex].insert( pMesh->mTexCoords[pInput.mIndex].end(),
                          pMesh->mPositions.size() - pMesh->mTexCoords[pInput.mIndex].size() - 1, aiVector3D( 0, 0, 0));
  
                  pMesh->mTexCoords[pInput.mIndex].push_back( aiVector3D( obj[0], obj[1], obj[2]));
                  if (0 != acc.mSubOffset[2] || 0 != acc.mSubOffset[3]) /* hack ... consider cleaner solution */
                      pMesh->mNumUVComponents[pInput.mIndex]=3;
              }   else
              {
                  DefaultLogger::get()->error("Collada: too many texture coordinate sets. Skipping.");
              }
              break;
          case IT_Color:
              // up to 4 color sets are fine, ignore the others
              if( pInput.mIndex < AI_MAX_NUMBER_OF_COLOR_SETS)
              {
                  // pad to current vertex count if necessary
                  if( pMesh->mColors[pInput.mIndex].size() < pMesh->mPositions.size()-1)
                      pMesh->mColors[pInput.mIndex].insert( pMesh->mColors[pInput.mIndex].end(),
                          pMesh->mPositions.size() - pMesh->mColors[pInput.mIndex].size() - 1, aiColor4D( 0, 0, 0, 1));
  
                  aiColor4D result(0, 0, 0, 1);
                  for (size_t i = 0; i < pInput.mResolved->mSize; ++i)
                  {
                      result[i] = obj[pInput.mResolved->mSubOffset[i]];
                  }
                  pMesh->mColors[pInput.mIndex].push_back(result);
              } else
              {
                  DefaultLogger::get()->error("Collada: too many vertex color sets. Skipping.");
              }
  
              break;
          default:
              // IT_Invalid and IT_Vertex
              ai_assert(false && "shouldn't ever get here");
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the library of node hierarchies and scene parts
  void ColladaParser::ReadSceneLibrary()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              // a visual scene - generate root node under its ID and let ReadNode() do the recursive work
              if( IsElement( "visual_scene"))
              {
                  // read ID. Is optional according to the spec, but how on earth should a scene_instance refer to it then?
                  int indexID = GetAttribute( "id");
                  const char* attrID = mReader->getAttributeValue( indexID);
  
                  // read name if given.
                  int indexName = TestAttribute( "name");
                  const char* attrName = "unnamed";
                  if( indexName > -1)
                      attrName = mReader->getAttributeValue( indexName);
  
                  // create a node and store it in the library under its ID
                  Node* node = new Node;
                  node->mID = attrID;
                  node->mName = attrName;
                  mNodeLibrary[node->mID] = node;
  
                  ReadSceneNode( node);
              } else
              {
                  // ignore the rest
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
          {
              if( strcmp( mReader->getNodeName(), "library_visual_scenes") == 0)
                  //ThrowException( "Expected end of \"library_visual_scenes\" element.");
  
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a scene node's contents including children and stores it in the given node
  void ColladaParser::ReadSceneNode( Node* pNode)
  {
      // quit immediately on <bla/> elements
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
          {
              if( IsElement( "node"))
              {
                  Node* child = new Node;
                  int attrID = TestAttribute( "id");
                  if( attrID > -1)
                      child->mID = mReader->getAttributeValue( attrID);
                  int attrSID = TestAttribute( "sid");
                  if( attrSID > -1)
                      child->mSID = mReader->getAttributeValue( attrSID);
  
                  int attrName = TestAttribute( "name");
                  if( attrName > -1)
                      child->mName = mReader->getAttributeValue( attrName);
  
                  // TODO: (thom) support SIDs
                  // ai_assert( TestAttribute( "sid") == -1);
  
                  if (pNode)
                  {
                      pNode->mChildren.push_back( child);
                      child->mParent = pNode;
                  }
                  else
                  {
                      // no parent node given, probably called from <library_nodes> element.
                      // create new node in node library
                      mNodeLibrary[child->mID] = child;
                  }
  
                  // read on recursively from there
                  ReadSceneNode( child);
                  continue;
              }
              // For any further stuff we need a valid node to work on
              else if (!pNode)
                  continue;
  
              if( IsElement( "lookat"))
                  ReadNodeTransformation( pNode, TF_LOOKAT);
              else if( IsElement( "matrix"))
                  ReadNodeTransformation( pNode, TF_MATRIX);
              else if( IsElement( "rotate"))
                  ReadNodeTransformation( pNode, TF_ROTATE);
              else if( IsElement( "scale"))
                  ReadNodeTransformation( pNode, TF_SCALE);
              else if( IsElement( "skew"))
                  ReadNodeTransformation( pNode, TF_SKEW);
              else if( IsElement( "translate"))
                  ReadNodeTransformation( pNode, TF_TRANSLATE);
              else if( IsElement( "render") && pNode->mParent == NULL && 0 == pNode->mPrimaryCamera.length())
              {
                  // ... scene evaluation or, in other words, postprocessing pipeline,
                  // or, again in other words, a turing-complete description how to
                  // render a Collada scene. The only thing that is interesting for
                  // us is the primary camera.
                  int attrId = TestAttribute("camera_node");
                  if (-1 != attrId)
                  {
                      const char* s = mReader->getAttributeValue(attrId);
                      if (s[0] != '#')
                          DefaultLogger::get()->error("Collada: Unresolved reference format of camera");
                      else
                          pNode->mPrimaryCamera = s+1;
                  }
              }
              else if( IsElement( "instance_node"))
              {
                  // find the node in the library
                  int attrID = TestAttribute( "url");
                  if( attrID != -1)
                  {
                      const char* s = mReader->getAttributeValue(attrID);
                      if (s[0] != '#')
                          DefaultLogger::get()->error("Collada: Unresolved reference format of node");
                      else
                      {
                          pNode->mNodeInstances.push_back(NodeInstance());
                          pNode->mNodeInstances.back().mNode = s+1;
                      }
                  }
              }
              else if( IsElement( "instance_geometry") || IsElement( "instance_controller"))
              {
                  // Reference to a mesh or controller, with possible material associations
                  ReadNodeGeometry( pNode);
              }
              else if( IsElement( "instance_light"))
              {
                  // Reference to a light, name given in 'url' attribute
                  int attrID = TestAttribute("url");
                  if (-1 == attrID)
                      DefaultLogger::get()->warn("Collada: Expected url attribute in <instance_light> element");
                  else
                  {
                      const char* url = mReader->getAttributeValue( attrID);
                      if( url[0] != '#')
                          ThrowException( "Unknown reference format in <instance_light> element");
  
                      pNode->mLights.push_back(LightInstance());
                      pNode->mLights.back().mLight = url+1;
                  }
              }
              else if( IsElement( "instance_camera"))
              {
                  // Reference to a camera, name given in 'url' attribute
                  int attrID = TestAttribute("url");
                  if (-1 == attrID)
                      DefaultLogger::get()->warn("Collada: Expected url attribute in <instance_camera> element");
                  else
                  {
                      const char* url = mReader->getAttributeValue( attrID);
                      if( url[0] != '#')
                          ThrowException( "Unknown reference format in <instance_camera> element");
  
                      pNode->mCameras.push_back(CameraInstance());
                      pNode->mCameras.back().mCamera = url+1;
                  }
              }
              else
              {
                  // skip everything else for the moment
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END) {
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a node transformation entry of the given type and adds it to the given node's transformation list.
  void ColladaParser::ReadNodeTransformation( Node* pNode, TransformType pType)
  {
      if( mReader->isEmptyElement())
          return;
  
      std::string tagName = mReader->getNodeName();
  
      Transform tf;
      tf.mType = pType;
  
      // read SID
      int indexSID = TestAttribute( "sid");
      if( indexSID >= 0)
          tf.mID = mReader->getAttributeValue( indexSID);
  
      // how many parameters to read per transformation type
      static const unsigned int sNumParameters[] = { 9, 4, 3, 3, 7, 16 };
      const char* content = GetTextContent();
  
      // read as many parameters and store in the transformation
      for( unsigned int a = 0; a < sNumParameters[pType]; a++)
      {
          // read a number
          content = fast_atoreal_move<float>( content, tf.f[a]);
          // skip whitespace after it
          SkipSpacesAndLineEnd( &content);
      }
  
      // place the transformation at the queue of the node
      pNode->mTransforms.push_back( tf);
  
      // and consume the closing tag
      TestClosing( tagName.c_str());
  }
  
  // ------------------------------------------------------------------------------------------------
  // Processes bind_vertex_input and bind elements
  void ColladaParser::ReadMaterialVertexInputBinding( Collada::SemanticMappingTable& tbl)
  {
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "bind_vertex_input"))
              {
                  Collada::InputSemanticMapEntry vn;
  
                  // effect semantic
                  int n = GetAttribute("semantic");
                  std::string s = mReader->getAttributeValue(n);
  
                  // input semantic
                  n = GetAttribute("input_semantic");
                  vn.mType = GetTypeForSemantic( mReader->getAttributeValue(n) );
  
                  // index of input set
                  n = TestAttribute("input_set");
                  if (-1 != n)
                      vn.mSet = mReader->getAttributeValueAsInt(n);
  
                  tbl.mMap[s] = vn;
              }
              else if( IsElement( "bind")) {
                  DefaultLogger::get()->warn("Collada: Found unsupported <bind> element");
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)    {
              if( strcmp( mReader->getNodeName(), "instance_material") == 0)
                  break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads a mesh reference in a node and adds it to the node's mesh list
  void ColladaParser::ReadNodeGeometry( Node* pNode)
  {
      // referred mesh is given as an attribute of the <instance_geometry> element
      int attrUrl = GetAttribute( "url");
      const char* url = mReader->getAttributeValue( attrUrl);
      if( url[0] != '#')
          ThrowException( "Unknown reference format");
  
      Collada::MeshInstance instance;
      instance.mMeshOrController = url+1; // skipping the leading #
  
      if( !mReader->isEmptyElement())
      {
          // read material associations. Ignore additional elements inbetween
          while( mReader->read())
          {
              if( mReader->getNodeType() == irr::io::EXN_ELEMENT)
              {
                  if( IsElement( "instance_material"))
                  {
                      // read ID of the geometry subgroup and the target material
                      int attrGroup = GetAttribute( "symbol");
                      std::string group = mReader->getAttributeValue( attrGroup);
                      int attrMaterial = GetAttribute( "target");
                      const char* urlMat = mReader->getAttributeValue( attrMaterial);
                      Collada::SemanticMappingTable s;
                      if( urlMat[0] == '#')
                          urlMat++;
  
                      s.mMatName = urlMat;
  
                      // resolve further material details + THIS UGLY AND NASTY semantic mapping stuff
                      if( !mReader->isEmptyElement())
                          ReadMaterialVertexInputBinding(s);
  
                      // store the association
                      instance.mMaterials[group] = s;
                  }
              }
              else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
              {
                  if( strcmp( mReader->getNodeName(), "instance_geometry") == 0
                      || strcmp( mReader->getNodeName(), "instance_controller") == 0)
                      break;
              }
          }
      }
  
      // store it
      pNode->mMeshes.push_back( instance);
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the collada scene
  void ColladaParser::ReadScene()
  {
      if( mReader->isEmptyElement())
          return;
  
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT) {
              if( IsElement( "instance_visual_scene"))
              {
                  // should be the first and only occurence
                  if( mRootNode)
                      ThrowException( "Invalid scene containing multiple root nodes in <instance_visual_scene> element");
  
                  // read the url of the scene to instance. Should be of format "#some_name"
                  int urlIndex = GetAttribute( "url");
                  const char* url = mReader->getAttributeValue( urlIndex);
                  if( url[0] != '#')
                      ThrowException( "Unknown reference format in <instance_visual_scene> element");
  
                  // find the referred scene, skip the leading #
                  NodeLibrary::const_iterator sit = mNodeLibrary.find( url+1);
                  if( sit == mNodeLibrary.end())
                      ThrowException( "Unable to resolve visual_scene reference \"" + std::string(url) + "\" in <instance_visual_scene> element.");
                  mRootNode = sit->second;
              } else  {
                  SkipElement();
              }
          }
          else if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END){
              break;
          }
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Aborts the file reading with an exception
  AI_WONT_RETURN void ColladaParser::ThrowException( const std::string& pError) const
  {
      throw DeadlyImportError( boost::str( boost::format( "Collada: %s - %s") % mFileName % pError));
  }
  
  // ------------------------------------------------------------------------------------------------
  // Skips all data until the end node of the current element
  void ColladaParser::SkipElement()
  {
      // nothing to skip if it's an <element />
      if( mReader->isEmptyElement())
          return;
  
      // reroute
      SkipElement( mReader->getNodeName());
  }
  
  // ------------------------------------------------------------------------------------------------
  // Skips all data until the end node of the given element
  void ColladaParser::SkipElement( const char* pElement)
  {
      // copy the current node's name because it'a pointer to the reader's internal buffer,
      // which is going to change with the upcoming parsing
      std::string element = pElement;
      while( mReader->read())
      {
          if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END)
              if( mReader->getNodeName() == element)
                  break;
      }
  }
  
  // ------------------------------------------------------------------------------------------------
  // Tests for an opening element of the given name, throws an exception if not found
  void ColladaParser::TestOpening( const char* pName)
  {
      // read element start
      if( !mReader->read())
          ThrowException( boost::str( boost::format( "Unexpected end of file while beginning of <%s> element.") % pName));
      // whitespace in front is ok, just read again if found
      if( mReader->getNodeType() == irr::io::EXN_TEXT)
          if( !mReader->read())
              ThrowException( boost::str( boost::format( "Unexpected end of file while reading beginning of <%s> element.") % pName));
  
      if( mReader->getNodeType() != irr::io::EXN_ELEMENT || strcmp( mReader->getNodeName(), pName) != 0)
          ThrowException( boost::str( boost::format( "Expected start of <%s> element.") % pName));
  }
  
  // ------------------------------------------------------------------------------------------------
  // Tests for the closing tag of the given element, throws an exception if not found
  void ColladaParser::TestClosing( const char* pName)
  {
      // check if we're already on the closing tag and return right away
      if( mReader->getNodeType() == irr::io::EXN_ELEMENT_END && strcmp( mReader->getNodeName(), pName) == 0)
          return;
  
      // if not, read some more
      if( !mReader->read())
          ThrowException( boost::str( boost::format( "Unexpected end of file while reading end of <%s> element.") % pName));
      // whitespace in front is ok, just read again if found
      if( mReader->getNodeType() == irr::io::EXN_TEXT)
          if( !mReader->read())
              ThrowException( boost::str( boost::format( "Unexpected end of file while reading end of <%s> element.") % pName));
  
      // but this has the be the closing tag, or we're lost
      if( mReader->getNodeType() != irr::io::EXN_ELEMENT_END || strcmp( mReader->getNodeName(), pName) != 0)
          ThrowException( boost::str( boost::format( "Expected end of <%s> element.") % pName));
  }
  
  // ------------------------------------------------------------------------------------------------
  // Returns the index of the named attribute or -1 if not found. Does not throw, therefore useful for optional attributes
  int ColladaParser::GetAttribute( const char* pAttr) const
  {
      int index = TestAttribute( pAttr);
      if( index != -1)
          return index;
  
      // attribute not found -> throw an exception
      ThrowException( boost::str( boost::format( "Expected attribute \"%s\" for element <%s>.") % pAttr % mReader->getNodeName()));
      return -1;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Tests the present element for the presence of one attribute, returns its index or throws an exception if not found
  int ColladaParser::TestAttribute( const char* pAttr) const
  {
      for( int a = 0; a < mReader->getAttributeCount(); a++)
          if( strcmp( mReader->getAttributeName( a), pAttr) == 0)
              return a;
  
      return -1;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the text contents of an element, throws an exception if not given. Skips leading whitespace.
  const char* ColladaParser::GetTextContent()
  {
      const char* sz = TestTextContent();
      if(!sz) {
          ThrowException( "Invalid contents in element \"n\".");
      }
      return sz;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Reads the text contents of an element, returns NULL if not given. Skips leading whitespace.
  const char* ColladaParser::TestTextContent()
  {
      // present node should be the beginning of an element
      if( mReader->getNodeType() != irr::io::EXN_ELEMENT || mReader->isEmptyElement())
          return NULL;
  
      // read contents of the element
      if( !mReader->read() )
          return NULL;
      if( mReader->getNodeType() != irr::io::EXN_TEXT)
          return NULL;
  
      // skip leading whitespace
      const char* text = mReader->getNodeData();
      SkipSpacesAndLineEnd( &text);
  
      return text;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Calculates the resulting transformation fromm all the given transform steps
  aiMatrix4x4 ColladaParser::CalculateResultTransform( const std::vector<Transform>& pTransforms) const
  {
      aiMatrix4x4 res;
  
      for( std::vector<Transform>::const_iterator it = pTransforms.begin(); it != pTransforms.end(); ++it)
      {
          const Transform& tf = *it;
          switch( tf.mType)
          {
              case TF_LOOKAT:
        {
          aiVector3D pos( tf.f[0], tf.f[1], tf.f[2]);
          aiVector3D dstPos( tf.f[3], tf.f[4], tf.f[5]);
          aiVector3D up = aiVector3D( tf.f[6], tf.f[7], tf.f[8]).Normalize();
          aiVector3D dir = aiVector3D( dstPos - pos).Normalize();
          aiVector3D right = (dir ^ up).Normalize();
  
          res *= aiMatrix4x4(
            right.x, up.x, -dir.x, pos.x,
            right.y, up.y, -dir.y, pos.y,
            right.z, up.z, -dir.z, pos.z,
            0, 0, 0, 1);
                  break;
        }
              case TF_ROTATE:
              {
                  aiMatrix4x4 rot;
                  float angle = tf.f[3] * float( AI_MATH_PI) / 180.0f;
                  aiVector3D axis( tf.f[0], tf.f[1], tf.f[2]);
                  aiMatrix4x4::Rotation( angle, axis, rot);
                  res *= rot;
                  break;
              }
              case TF_TRANSLATE:
              {
                  aiMatrix4x4 trans;
                  aiMatrix4x4::Translation( aiVector3D( tf.f[0], tf.f[1], tf.f[2]), trans);
                  res *= trans;
                  break;
              }
              case TF_SCALE:
              {
                  aiMatrix4x4 scale( tf.f[0], 0.0f, 0.0f, 0.0f, 0.0f, tf.f[1], 0.0f, 0.0f, 0.0f, 0.0f, tf.f[2], 0.0f,
                      0.0f, 0.0f, 0.0f, 1.0f);
                  res *= scale;
                  break;
              }
              case TF_SKEW:
                  // TODO: (thom)
                  ai_assert( false);
                  break;
              case TF_MATRIX:
              {
                  aiMatrix4x4 mat( tf.f[0], tf.f[1], tf.f[2], tf.f[3], tf.f[4], tf.f[5], tf.f[6], tf.f[7],
                      tf.f[8], tf.f[9], tf.f[10], tf.f[11], tf.f[12], tf.f[13], tf.f[14], tf.f[15]);
                  res *= mat;
                  break;
              }
              default:
                  ai_assert( false);
                  break;
          }
      }
  
      return res;
  }
  
  // ------------------------------------------------------------------------------------------------
  // Determines the input data type for the given semantic string
  Collada::InputType ColladaParser::GetTypeForSemantic( const std::string& pSemantic)
  {
      if( pSemantic == "POSITION")
          return IT_Position;
      else if( pSemantic == "TEXCOORD")
          return IT_Texcoord;
      else if( pSemantic == "NORMAL")
          return IT_Normal;
      else if( pSemantic == "COLOR")
          return IT_Color;
      else if( pSemantic == "VERTEX")
          return IT_Vertex;
      else if( pSemantic == "BINORMAL" || pSemantic ==  "TEXBINORMAL")
          return IT_Bitangent;
      else if( pSemantic == "TANGENT" || pSemantic == "TEXTANGENT")
          return IT_Tangent;
  
      DefaultLogger::get()->warn( boost::str( boost::format( "Unknown vertex input type \"%s\". Ignoring.") % pSemantic));
      return IT_Invalid;
  }
  
  #endif // !! ASSIMP_BUILD_NO_DAE_IMPORTER
  