Method UpdateDiscreteCursor

Interaction/Widgets/vtkImagePlaneWidget.cxx:2125–2167

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//------------------------------------------------------------------------------
int vtkImagePlaneWidget::UpdateDiscreteCursor(double* q)
{
  // vtkImageData will find the nearest implicit point to q
  //
  vtkIdType ptId = this->ImageData->FindPoint(q);

  if (ptId == -1)
  {
    return 0;
  }

  double closestPt[3];
  this->ImageData->GetPoint(ptId, closestPt);

  double origin[3];
  this->ImageData->GetOrigin(origin);
  double spacing[3];
  this->ImageData->GetSpacing(spacing);
  int extent[6];
  this->ImageData->GetExtent(extent);

  int iq[3];
  int iqtemp;
  for (int i = 0; i < 3; i++)
  {
    // compute world to image coords
    iqtemp = static_cast<int>(std::round((closestPt[i] - origin[i]) / spacing[i]));

    // we have a valid pick already, just enforce bounds check
    iq[i] = std::min(std::max(iqtemp, extent[2 * i]), extent[2 * i + 1]);

    // compute image to world coords
    q[i] = iq[i] * spacing[i] + origin[i];

    this->CurrentCursorPosition[i] = iq[i];
  }

  this->CurrentImageValue =
    this->ImageData->GetScalarComponentAsDouble(static_cast<int>(this->CurrentCursorPosition[0]),
      static_cast<int>(this->CurrentCursorPosition[1]),
      static_cast<int>(this->CurrentCursorPosition[2]), 0);
  return 1;
}

//------------------------------------------------------------------------------
void vtkImagePlaneWidget::SetOrigin(double x, double y, double z)