Method UpdateCache

Charts/Core/vtkPlotHistogram2D.cxx:298–331

------------------------------------------------------------------------------

//------------------------------------------------------------------------------
bool vtkPlotHistogram2D::UpdateCache()
{
  if (!this->Input)
  {
    return false;
  }
  if (!this->Output)
  {
    this->Output = vtkSmartPointer<vtkImageData>::New();
  }
  this->Output->SetExtent(this->Input->GetExtent());
  this->Output->AllocateScalars(VTK_UNSIGNED_CHAR, 4);

  if (this->TransferFunction)
  {
    vtkDataArray* inputDataArray = nullptr;
    void* const inputVoidArray = this->GetInputArrayPointer(inputDataArray);

    if (!inputVoidArray || !inputDataArray)
    {
      return false;
    }

    const int inputType = inputDataArray->GetDataType();
    const int nbComponents = inputDataArray->GetNumberOfComponents();
    const int dimension = this->Input->GetDimensions()[0] * this->Input->GetDimensions()[1];
    unsigned char* output = reinterpret_cast<unsigned char*>(this->Output->GetScalarPointer());

    this->TransferFunction->MapScalarsThroughTable2(
      inputVoidArray, output, inputType, dimension, nbComponents, 4);
  }

  return true;
}

//------------------------------------------------------------------------------
void* vtkPlotHistogram2D::GetInputArrayPointer(vtkDataArray*& inputArray)