Method ComputeRectangle

Rendering/Core/vtkTextActor.cxx:749–845

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//------------------------------------------------------------------------------
void vtkTextActor::ComputeRectangle(vtkViewport* viewport)
{
  int dims[2] = { 0, 0 };
  int anchorOffset[2] = { 0, 0 };

  this->RectanglePoints->Reset();
  if (this->ImageData)
  {
    int p2dims[3];
    this->ImageData->GetDimensions(p2dims);
    int text_bbox[4];
    if (!this->GetImageBoundingBox(this->ScaledTextProperty, viewport, text_bbox))
    {
      vtkErrorMacro("Cannot compute bounding box.");
      return;
    }
    dims[0] = (text_bbox[1] - text_bbox[0] + 1);
    dims[1] = (text_bbox[3] - text_bbox[2] + 1);
    anchorOffset[0] = text_bbox[0];
    anchorOffset[1] = text_bbox[2];

    // compute TCoords.
    vtkFloatArray* tc =
      vtkArrayDownCast<vtkFloatArray>(this->Rectangle->GetPointData()->GetTCoords());
    float tcXMax, tcYMax;
    // Add a fudge factor to the texture coordinates to prevent the top
    // row of pixels from being truncated on some systems.
    tcXMax = std::min(1.0f, (dims[0] + 0.001f) / static_cast<float>(p2dims[0]));
    tcYMax = std::min(1.0f, (dims[1] + 0.001f) / static_cast<float>(p2dims[1]));
    tc->InsertComponent(0, 0, 0.0);
    tc->InsertComponent(0, 1, 0.0);

    tc->InsertComponent(1, 0, 0.0);
    tc->InsertComponent(1, 1, tcYMax);

    tc->InsertComponent(2, 0, tcXMax);
    tc->InsertComponent(2, 1, tcYMax);

    tc->InsertComponent(3, 0, tcXMax);
    tc->InsertComponent(3, 1, 0.0);
    tc->Modified();
  }

  double xo = 0.0, yo = 0.0;

  // When TextScaleMode is PROP, we justify text based on the rectangle
  // formed by Position & Position2 coordinates
  if ((this->TextScaleMode == TEXT_SCALE_MODE_PROP) || this->UseBorderAlign)
  {
    double position1[3], position2[3];
    this->PositionCoordinate->GetValue(position1);
    this->Position2Coordinate->GetValue(position2);
    this->SpecifiedToDisplay(position1, viewport, this->PositionCoordinate->GetCoordinateSystem());
    this->SpecifiedToDisplay(position2, viewport, this->Position2Coordinate->GetCoordinateSystem());
    double maxWidth = position2[0] - position1[0];
    double maxHeight = position2[1] - position1[1];
    switch (this->TextProperty->GetJustification())
    {