Function WriteTextureBufferAndView

IO/Geometry/vtkGLTFWriter.cxx:228–325

}

std::string WriteTextureBufferAndView(const std::string& gltfFullDir,
  const std::string& textureFullPath, bool inlineData, bool copyTextures, nlohmann::json& buffers,
  nlohmann::json& bufferViews)
{
  std::string gltfRelativeTexturePath =
    vtksys::SystemTools::RelativePath(gltfFullDir, textureFullPath);
  // if inline then base64 encode the data. In this case we need to read the texture
  std::string result;
  std::string mimeType;
  unsigned int byteLength = 0;
  if (inlineData)
  {
    vtkSmartPointer<vtkTexture> t;
    vtkSmartPointer<vtkImageData> id;

    auto textureReader = SetupTextureReader(textureFullPath);
    vtkNew<vtkTexture> texture;
    texture->SetInputConnection(textureReader->GetOutputPort());
    texture->Update();
    t = texture;
    id = t->GetInput();

    vtkUnsignedCharArray* da = nullptr;
    if (id && id->GetPointData()->GetScalars())
    {
      da = vtkUnsignedCharArray::SafeDownCast(id->GetPointData()->GetScalars());
    }
    if (!da)
    {
      return mimeType; /*empty mimeType signals error*/
    }

    vtkNew<vtkTrivialProducer> triv;
    triv->SetOutput(id);
    // no need to flip Y the texture as we flip the texture coordinates

    // convert to png
    vtkNew<vtkPNGWriter> png;
    png->SetCompressionLevel(5);
    png->SetInputConnection(triv->GetOutputPort());
    png->WriteToMemoryOn();
    png->Write();
    da = png->GetResult();

    mimeType = "image/png";

    result = "data:application/octet-stream;base64,";
    std::ostringstream toString;
    vtkNew<vtkBase64OutputStream> ostr;
    ostr->SetStream(&toString);
    ostr->StartWriting();
    vtkGLTFWriterUtils::WriteValues(da, ostr);
    ostr->EndWriting();
    result += toString.str();
    unsigned int count = da->GetNumberOfTuples() * da->GetNumberOfComponents();
    byteLength = da->GetElementComponentSize() * count;
  }
  else