Method ProcessColorArray

Views/Infovis/vtkApplyColors.cxx:367–417

}

void vtkApplyColors::ProcessColorArray(vtkUnsignedCharArray* colorArr, vtkScalarsToColors* lut,
  vtkAbstractArray* arr, unsigned char color[4], bool scaleToArray)
{
  if (lut && arr)
  {
    // If scaling is on, use data min/max.
    // Otherwise, use the lookup table range.
    const double* rng = lut->GetRange();
    double minVal = rng[0];
    double maxVal = rng[1];
    if (scaleToArray)
    {
      minVal = VTK_DOUBLE_MAX;
      maxVal = VTK_DOUBLE_MIN;
      for (vtkIdType i = 0; i < colorArr->GetNumberOfTuples(); ++i)
      {
        double val = arr->GetVariantValue(i).ToDouble();
        maxVal = std::max(val, maxVal);
        minVal = std::min(val, minVal);
      }
    }

    // Map the data values through the lookup table.
    double scale = 1.0;
    if (minVal != maxVal)
    {
      scale = (rng[1] - rng[0]) / (maxVal - minVal);
    }
    unsigned char myColor[4] = { 0, 0, 0, 0 };
    for (vtkIdType i = 0; i < colorArr->GetNumberOfTuples(); ++i)
    {
      double val = arr->GetVariantValue(i).ToDouble();
      const unsigned char* mappedColor = lut->MapValue(rng[0] + scale * (val - minVal));
      myColor[0] = mappedColor[0];
      myColor[1] = mappedColor[1];
      myColor[2] = mappedColor[2];
      // Combine the opacity of the lookup table with the
      // default color opacity.
      myColor[3] = static_cast<unsigned char>((color[3] / 255.0) * mappedColor[3]);
      colorArr->SetTypedTuple(i, myColor);
    }
  }
  else
  {
    // If no lookup table, use default color.
    for (vtkIdType i = 0; i < colorArr->GetNumberOfTuples(); ++i)
    {
      colorArr->SetTypedTuple(i, color);
    }
  }
}

vtkMTimeType vtkApplyColors::GetMTime()
{