Function GetTextureTransform

IO/Import/vtkGLTFImporter.cxx:202–280

}

vtkSmartPointer<vtkTransform2D> GetTextureTransform(const vtkGLTFDocumentLoader::Material& material)
{
  bool hasTransform = false;
  double offset[2] = { 0.0, 0.0 };
  double rotation = 0.0;
  double scale[2] = { 1.0, 1.0 };

  auto CheckAndSetTransform = [&](const vtkGLTFDocumentLoader::TextureInfo& texInfo)
  {
    if (texInfo.Index >= 0)
    {
      if (!hasTransform)
      {
        if (texInfo.Offset.size() == 2)
        {
          offset[0] = texInfo.Offset[0];
          offset[1] = texInfo.Offset[1];
        }

        if (texInfo.Scale.size() == 2)
        {
          scale[0] = texInfo.Scale[0];
          scale[1] = texInfo.Scale[1];
        }

        rotation = texInfo.Rotation;
        hasTransform = true;
      }
      else
      {
        constexpr double tolerance = 1e-6;

        if (texInfo.Offset.size() == 2 &&
          (!vtkMathUtilities::FuzzyCompare(texInfo.Offset[0], offset[0], tolerance) ||
            !vtkMathUtilities::FuzzyCompare(texInfo.Offset[1], offset[1], tolerance)))
        {
          vtkWarningWithObjectMacro(
            nullptr, "Found different texture transform offset value, this is not supported.");
        }

        if (texInfo.Scale.size() == 2 &&
          (!vtkMathUtilities::FuzzyCompare(texInfo.Scale[0], scale[0], tolerance) ||
            !vtkMathUtilities::FuzzyCompare(texInfo.Scale[1], scale[1], tolerance)))
        {
          vtkWarningWithObjectMacro(
            nullptr, "Found different texture transform scale value, this is not supported.");
        }

        if (!vtkMathUtilities::FuzzyCompare(texInfo.Rotation, rotation, tolerance))
        {
          vtkWarningWithObjectMacro(
            nullptr, "Found different texture transform rotation value, this is not supported.");
        }
      }
    }
  };

  CheckAndSetTransform(material.PbrMetallicRoughness.BaseColorTexture);