Method UpdateBufferObjects

Rendering/OpenGL2/vtkOpenGLPolyDataMapper.cxx:3738–3767

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//------------------------------------------------------------------------------
void vtkOpenGLPolyDataMapper::UpdateBufferObjects(vtkRenderer* ren, vtkActor* act)
{
  // Rebuild buffers if needed
  if (this->GetNeedToRebuildBufferObjects(ren, act))
  {
    this->BuildBufferObjects(ren, act);
  }

  // construct the selection IBO that will reuse the current VBO
  vtkSelection* sel = this->GetSelection();
  if (sel && sel->GetNumberOfNodes() > 0)
  {
    if (sel->GetMTime() > this->SelectionTime)
    {
      std::vector<unsigned int> indexArray[vtkOpenGLPolyDataMapper::PrimitiveTriStrips + 1];
      this->BuildSelectionIBO(this->CurrentInput, indexArray, 0);

      for (vtkIdType p = vtkOpenGLPolyDataMapper::PrimitiveStart;
           p <= vtkOpenGLPolyDataMapper::PrimitiveTriStrips; p++)
      {
        auto& ibo = this->SelectionPrimitives[p].IBO;

        ibo->Upload(indexArray[p], vtkOpenGLIndexBufferObject::ElementArrayBuffer);
        ibo->IndexCount = indexArray[p].size();
      }

      this->SelectionTime = sel->GetMTime();
    }
  }
}

//------------------------------------------------------------------------------
bool vtkOpenGLPolyDataMapper::GetNeedToRebuildBufferObjects(