Method DrawInteriorLines

Rendering/Matplotlib/vtkMatplotlibMathTextUtilities.cxx:1106–1175

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//------------------------------------------------------------------------------
bool vtkMatplotlibMathTextUtilities::DrawInteriorLines(
  vtkImageData* image, int bbox[4], vtkTextProperty* tprop)
{
  if (!image)
  {
    vtkErrorMacro("Invalid image.");
    return false;
  }

  // Define line offsets to take line width into account
  int extraLinesMin = 0;
  int extraLinesMax = 0;
  int width = tprop->GetInteriorLinesWidth();
  double* doubleColor = tprop->GetInteriorLinesColor();
  unsigned char color[3] = { static_cast<unsigned char>(doubleColor[0] * 255),
    static_cast<unsigned char>(doubleColor[1] * 255),
    static_cast<unsigned char>(doubleColor[2] * 255) };

  // Draw horizontal lines
  for (std::size_t lineIdx = 0; lineIdx < this->HorizontalLinesPosition.size(); ++lineIdx)
  {
    // Clamp line width to remain in bounds
    extraLinesMin = ((this->HorizontalLinesPosition[lineIdx] - (width / 2)) >= 0)
      ? (-width / 2)
      : (-this->HorizontalLinesPosition[lineIdx]);
    extraLinesMax = ((this->HorizontalLinesPosition[lineIdx] + (width / 2)) <= (bbox[3] - bbox[2]))
      ? ((width + 1) / 2)
      : ((bbox[3] - bbox[2]) - this->HorizontalLinesPosition[lineIdx]);

    for (int extraLineIdx = extraLinesMin; extraLineIdx < extraLinesMax; ++extraLineIdx)
    {
      for (int colIdx = bbox[0]; colIdx <= bbox[1]; ++colIdx)
      {
        unsigned char* ptr = static_cast<unsigned char*>(image->GetScalarPointer(
          colIdx, bbox[2] + this->HorizontalLinesPosition[lineIdx] + extraLineIdx, 0));
        ptr[0] = color[0];
        ptr[1] = color[1];
        ptr[2] = color[2];
        ptr[3] = 255;
      }
    }
  }

  // Draw vertical lines
  for (std::size_t lineIdx = 0; lineIdx < this->VerticalLinesPosition.size(); ++lineIdx)
  {
    // Clamp line width to remain in bounds
    extraLinesMin = ((this->VerticalLinesPosition[lineIdx] - (width / 2)) >= 0)
      ? (-width / 2)
      : (-this->VerticalLinesPosition[lineIdx]);
    extraLinesMax = ((this->VerticalLinesPosition[lineIdx] + (width / 2)) <= (bbox[1] - bbox[0]))
      ? ((width + 1) / 2)
      : ((bbox[1] - bbox[0]) - this->VerticalLinesPosition[lineIdx]);

    for (int extraLineIdx = extraLinesMin; extraLineIdx < extraLinesMax; ++extraLineIdx)
    {
      for (int rowIdx = bbox[2]; rowIdx <= bbox[3]; ++rowIdx)
      {