//! Adds a standard data block (type: priority update) to the chain of all data blocks.
//! Returns the total # of data blocks in the data block chain.
size_t U3DFileWriter::addStandardBlock_PriorityUpdate(const MLuint32 newPriority)
{
    U3DDataBlockWriter PriorityUpdateBlock;
    PriorityUpdateBlock.blockType = mlU3D::BLOCKTYPE_PRIORITYUPDATE;
    PriorityUpdateBlock.writeU32(newPriority);

    return addDataBlock(PriorityUpdateBlock);
}

//! Adds a standard data block (type: model node) to the chain of all data blocks.
//! Returns the total # of data blocks in the data block chain.
size_t U3DFileWriter::addStandardBlock_ModelNode(const U3DObjectInfoStruct& objectInfo)
{
  U3DDataBlockWriter ModelNodeBlock;
  ModelNodeBlock.blockType = U3D_BLOCKTYPE_MODELNODE;
  std::string parentName = getParentNameFromGroupPath(objectInfo.GroupPath);

  //ModelNodeBlock.writeString(objectInfo.DisplayName);        // Write Model Node Name (9.5.2.1) - Unfortunately, the model node name must be unique... :-(
  ModelNodeBlock.writeString(objectInfo.InternalName);       // Write Model Node Name (9.5.2.1)

  _writeParentNodeData(ModelNodeBlock, parentName);          // Write Parent Node Data (9.5.2.2)

  ModelNodeBlock.writeString(objectInfo.ResourceName);       // Write Model Resource Name (9.5.2.3) 
  ModelNodeBlock.writeU32(objectInfo.Visibility);            // Write Model Visibility (9.5.2.4);

  return addDataBlock(ModelNodeBlock);
}

mlU3D::ColorMap U3DSave::_writeVertexColors(WEMPatch* patch, U3DDataBlockWriter& continuationBlock) const
{
  MLuint thisColorIndex = 0;
  mlU3D::ColorMap colorsMap;   // <Color,ColorIndex>

  const int numNodesInPatch = patch->getNumNodes();

  for (int n = 0; n < numNodesInPatch; n++)
  {
    WEMNode* thisNode = patch->getNodeAt(n);

    const Vector4 thisNodeColor = thisNode->getColor();

    mlU3D::ColorMap::iterator findIt = colorsMap.find(thisNodeColor);

    if (findIt == colorsMap.end())
    {
      // Color has not yet been added to map, so add it now
      colorsMap[thisNodeColor] = thisColorIndex;
      continuationBlock.writeF32Color(thisNodeColor);
      thisColorIndex++;
    }
    else
    {
      // Do nothing
    }

  }

  return colorsMap;
}

//! Write parent node data to the respective position of a (child) node block. (private)
void U3DFileWriter::_writeParentNodeData(U3DDataBlockWriter& dataBlock, const std::string& parentNodeName)
{
    dataBlock.writeU32(0x00000001);         // Write Parent Node Count (9.5.1.2.1)
    dataBlock.writeString(parentNodeName);  // Write empty Parent Node Name (9.5.1.2.2)
    dataBlock.writeIdentityMatrix();        // Write Parent Node Transform Matrix (9.5.1.2.3) (identity matrix)
}

//! Write one block to file stream. (private)
bool U3DFileWriter::_writeBlockToFileStream(U3DDataBlockWriter& block, std::ofstream& ofstream)
{
    bool Success = false;

    MLuint32 flushBufferSize = block.getNumTotalBytes();

    mlU3D::DataBlockFundamental* flushBuffer = NULL;
    ML_CHECK_NEW(flushBuffer, mlU3D::DataBlockFundamental[flushBufferSize]);
    memset(flushBuffer, 0, flushBufferSize);

    if (NULL != flushBuffer)
    {
        // Add Block type, Data size & Meta data Size
        mlU3D::DataBlockFundamental flushBufferIndex = 0;
        flushBuffer[flushBufferIndex] = block.blockType;

        flushBufferIndex++;
        flushBuffer[flushBufferIndex] = block.getDataSizeWithChildDataBytes();

        flushBufferIndex++;
        flushBuffer[flushBufferIndex] = block.getMetaDataSizeWithoutPadding();

        flushBufferIndex++;


        // Add Data
        mlU3D::DataVector data = block.getData();
        for (mlU3D::DataBlockFundamental i = 0; i < block.getDataSize(); i++)
        {
            flushBuffer[flushBufferIndex] = data[i];
            flushBufferIndex++;
        }

        // Add Meta data
        mlU3D::DataVector metaData = block.getMetaData();
        for (mlU3D::DataBlockFundamental i = 0; i < block.getMetaDataSize(); i++)
        {
            flushBuffer[flushBufferIndex] = metaData[i];
            flushBufferIndex++;
        }
    }
    else
    {
        flushBufferSize = 0;
    }

    if ((0 != flushBufferSize) && (block.blockType != 0))
    {
        try
        {
            ofstream.write(reinterpret_cast<char*>(flushBuffer), flushBufferSize);
            ofstream.flush();
            Success = true;
        }
        catch (...)
        {
            // Ignore errors
        }
    }

    ML_DELETE_ARRAY(flushBuffer);

    return Success;
}

U3DDataBlockWriter U3DSave::_createCLODBaseMeshContinuationBlock(WEMTrianglePatch* meshPatch, mlU3D::CLODMeshGenerator& meshGenerator) const
{
  mlU3D::ColorMap baseDiffuseColorsMap;

  float progressStart = 0.2f;
  float progressEnd = 0.9f;
  float progressRangeforAllMeshes = progressEnd - progressStart; // 0.7

  float progressIntervalForOneWEMPatch = progressRangeforAllMeshes / _inU3DObject->meshes.size();
  float progressStartForThisMesh = progressStart + progressIntervalForOneWEMPatch * meshGenerator.meshNumber;
  _progressFld->setFloatValue(progressStartForThisMesh);
  _statusFld->setStringValue("Assembling data for Mesh: " + meshGenerator.resourceName + ".");

  U3DDataBlockWriter thisCLODBaseMeshContinuationBlock;
  thisCLODBaseMeshContinuationBlock.blockType = mlU3D::BLOCKTYPE_CLODBASEMESHCONTINUATION;

  thisCLODBaseMeshContinuationBlock.writeString(meshGenerator.resourceName);       // Write Mesh Name (9.6.1.2.1)
  thisCLODBaseMeshContinuationBlock.writeU32(mlU3D::ReservedZero);               // Write Chain Index (9.6.1.2.2) (shall be zero) 
  thisCLODBaseMeshContinuationBlock.writeU32(meshGenerator.faceCount);            // Write Base Mesh Description - Face Count (9.6.1.2.3.1) (# of faces)
  thisCLODBaseMeshContinuationBlock.writeU32(meshGenerator.vertexCount);          // Write Base Mesh Description - Position Count (9.6.1.2.3.2) (# of vertices)
  thisCLODBaseMeshContinuationBlock.writeU32(meshGenerator.normalCount);          // Write Base Mesh Description - Normal Count (9.6.1.2.3.3) (# of normals)
  thisCLODBaseMeshContinuationBlock.writeU32(meshGenerator.diffuseColorCount);    // Write Base Mesh Description - Diffuse Color Count (9.6.1.2.3.4)
  thisCLODBaseMeshContinuationBlock.writeU32(meshGenerator.specularColorCount);   // Write Base Mesh Description - Specular Color Count (9.6.1.2.3.5)
  thisCLODBaseMeshContinuationBlock.writeU32(0x00000001);                    // Write Base Mesh Description - Texture Coord Count (9.6.1.2.3.6)

  // Write all vertex positions (in U3D, vertices are called "positions")        
  for (MLuint32 thisVertex = 0; thisVertex < meshGenerator.vertexCount; thisVertex++)
  {
    Vector3 wemPosition = meshPatch->getNodeAt(thisVertex)->getPosition();

    thisCLODBaseMeshContinuationBlock.writeF32(wemPosition[0]);             // Write Base Position - X (9.6.1.2.4.1.1)
    thisCLODBaseMeshContinuationBlock.writeF32(wemPosition[1]);             // Write Base Position - Y (9.6.1.2.4.1.2)
    thisCLODBaseMeshContinuationBlock.writeF32(wemPosition[2]);             // Write Base Position - Z (9.6.1.2.4.1.3)
  }

  for (MLuint32 thisNormal = 0; thisNormal < meshGenerator.normalCount; thisNormal++)
  {
    Vector3 nodeNormal = meshPatch->getNodeAt(thisNormal)->getNormal();

    thisCLODBaseMeshContinuationBlock.writeF32(nodeNormal[0]);              // Write Base Normal - X (9.6.1.2.4.2.1)
    thisCLODBaseMeshContinuationBlock.writeF32(nodeNormal[1]);              // Write Base Normal - Y (9.6.1.2.4.2.2)
    thisCLODBaseMeshContinuationBlock.writeF32(nodeNormal[2]);              // Write Base Normal - Z (9.6.1.2.4.2.3)
  }

  if (meshGenerator.diffuseColorCount > 0)
  {
    baseDiffuseColorsMap = _writeVertexColors(meshPatch, thisCLODBaseMeshContinuationBlock); // Write all Base Diffuse Colors (9.6.1.2.4.3)
  }

  for (MLuint32 thisSpecularColor = 0; thisSpecularColor < meshGenerator.specularColorCount; thisSpecularColor++)
  {
    thisCLODBaseMeshContinuationBlock.writeF32Color(_inU3DObject->defaultValues.defaultMaterialSpecularColor, 1.0f);   // Write Base Specular Color (9.6.1.2.4.4)
  }

  // Write Write Base Texture Coord (9.6.1.2.4.5)
  thisCLODBaseMeshContinuationBlock.writeF32(0.0f);       // Write Base Texture Coord U (9.6.1.2.4.5.1)
  thisCLODBaseMeshContinuationBlock.writeF32(0.0f);       // Write Base Texture Coord V (9.6.1.2.4.5.2)
  thisCLODBaseMeshContinuationBlock.writeF32(0.0f);       // Write Base Texture Coord S (9.6.1.2.4.5.3)
  thisCLODBaseMeshContinuationBlock.writeF32(0.0f);       // Write Base Texture Coord T (9.6.1.2.4.5.4)

  for (MLuint32 thisFace = 0; thisFace < meshGenerator.faceCount; thisFace++)
  {
    thisCLODBaseMeshContinuationBlock.writeCompressedU32(mlU3D::Context_cShading, 0);       // Write Shading ID (9.6.1.2.4.6.1)

    WEMFace* wemFace = meshPatch->getFaceAt(thisFace);

    for (MLuint thisNode = 0; thisNode < 3; thisNode++)
    {
      WEMNode* thisWEMNode = wemFace->getNodeAt(static_cast<unsigned int>(thisNode));
      const MLuint32 VertexIndex = thisWEMNode->getEntryNumber();
      const Vector4 thisWEMNodeColor = thisWEMNode->getColor();
      MLuint32 NormalIndex = VertexIndex;

      // Write Base Corner Info - Base Position Index (9.6.1.2.4.6.2.1)
      thisCLODBaseMeshContinuationBlock.writeCompressedU32(mlU3D::Context_StaticFull + meshGenerator.vertexCount, VertexIndex);

      // Write Base Corner Info - Base Normal Index (9.6.1.2.4.6.2.2)
      if (meshGenerator.normalCount > 0)
      {
        thisCLODBaseMeshContinuationBlock.writeCompressedU32(mlU3D::Context_StaticFull + meshGenerator.normalCount, NormalIndex);
      }

      // Write Base Corner Info - Base Diffuse Color Index (9.6.1.2.4.6.2.3)
      if (meshGenerator.diffuseColorCount > 0)
      {
        MLuint32 diffuseColorIndex = baseDiffuseColorsMap[thisWEMNodeColor];
        thisCLODBaseMeshContinuationBlock.writeCompressedU32(mlU3D::Context_StaticFull + meshGenerator.diffuseColorCount, diffuseColorIndex);
      }

      // Write Base Corner Info - Base Specular Color Index (9.6.1.2.4.6.2.4)
      if (meshGenerator.specularColorCount > 0)
      {
        thisCLODBaseMeshContinuationBlock.writeCompressedU32(mlU3D::Context_StaticFull + meshGenerator.specularColorCount, 0);
      }

      // Write Base Corner Info - Base Texture Coord Index (9.6.1.2.4.6.2.5)
      //thisCLODBaseMeshContinuationBlock.writeCompressedU32(U3D_StaticFull+1, 0);  // No texture layers
    }

    if (0 == (thisFace % 100))   // Set progress field every 100 faces to save GUI update cost
//.........这里部分代码省略.........