Method UpdateMaximumPointCellIds

Rendering/OpenGL2/vtkOpenGLPolyDataMapper.cxx:3355–3413

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

//------------------------------------------------------------------------------
void vtkOpenGLPolyDataMapper::UpdateMaximumPointCellIds(vtkRenderer* ren, vtkActor* actor)
{
  vtkHardwareSelector* selector = ren->GetSelector();

  // our maximum point id is the is the index of the max of
  // 1) the maximum used value in our points array
  // 2) the largest used value in a provided pointIdArray
  // To make this quicker we use the number of points for (1)
  // and the max range for (2)
  vtkIdType maxPointId = this->CurrentInput->GetPoints()->GetNumberOfPoints() - 1;
  if (this->CurrentInput && this->CurrentInput->GetPointData())
  {
    vtkIdTypeArray* pointArrayId = this->PointIdArrayName
      ? vtkArrayDownCast<vtkIdTypeArray>(
          this->CurrentInput->GetPointData()->GetArray(this->PointIdArrayName))
      : nullptr;
    if (pointArrayId)
    {
      maxPointId =
        maxPointId < pointArrayId->GetRange()[1] ? pointArrayId->GetRange()[1] : maxPointId;
    }
  }
  selector->UpdateMaximumPointId(maxPointId);

  // the maximum number of cells in a draw call is the max of
  // 1) the sum of IBO size divided by the stride
  // 2) the max of any used call in a cellIdArray
  vtkIdType maxCellId = 0;
  int representation = actor->GetProperty()->GetRepresentation();
  for (int i = vtkOpenGLPolyDataMapper::PrimitiveStart;
       i < vtkOpenGLPolyDataMapper::PrimitiveVertices; i++)
  {
    if (this->Primitives[i].IBO->IndexCount)
    {
      GLenum mode = this->GetOpenGLMode(representation, i);
      if (this->PointPicking)
      {
        mode = GL_POINTS;
      }
      // NOLINTNEXTLINE(readability-avoid-nested-conditional-operator)
      unsigned int stride = (mode == GL_POINTS ? 1 : (mode == GL_LINES ? 2 : 3));
      vtkIdType strideMax = static_cast<vtkIdType>(this->Primitives[i].IBO->IndexCount / stride);
      maxCellId += strideMax;
    }
  }

  if (this->CurrentInput && this->CurrentInput->GetCellData())
  {
    vtkIdTypeArray* cellArrayId = this->CellIdArrayName
      ? vtkArrayDownCast<vtkIdTypeArray>(
          this->CurrentInput->GetCellData()->GetArray(this->CellIdArrayName))
      : nullptr;
    if (cellArrayId)
    {
      maxCellId = maxCellId < cellArrayId->GetRange()[1] ? cellArrayId->GetRange()[1] : maxCellId;
    }
  }
  selector->UpdateMaximumCellId(maxCellId);