Method Draw

Rendering/OpenGL2/vtkOpenGLLowMemoryCellTypeAgent.cxx:117–160

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//------------------------------------------------------------------------------
void vtkOpenGLLowMemoryCellTypeAgent::Draw(vtkRenderer* renderer, vtkActor* actor,
  vtkOpenGLLowMemoryPolyDataMapper* mapper,
  const std::vector<vtkOpenGLLowMemoryPolyDataMapper::CellGroupInformation>& cellGroups,
  std::size_t cellGroupIdx /*=0*/) const
{
  if (!mapper)
  {
    return;
  }
  if (cellGroupIdx >= cellGroups.size())
  {
    std::cerr << cellGroupIdx << " > " << cellGroups.size() << std::endl;
    return;
  }
  const auto& cellGroup = cellGroups[cellGroupIdx];
  if (!cellGroup.CanRender)
  {
    return;
  }
#ifdef vtkOpenGLLowMemoryCellTypeAgent_DEBUG
  std::cout << this << " Draw CellGroups[" << cellGroupIdx << '/' << cellGroups.size()
            << "]: " << cellGroup << '\n';
#endif
  const auto& offsets = cellGroup.Offsets;
  mapper->FirstVertexId = offsets.VertexIdOffset;
  mapper->NumberOfElements = cellGroup.NumberOfElements;
  // when rendering vertices, increase number of elements and draw 1 instance.
  if (actor->GetProperty()->GetRepresentation() == VTK_POINTS || this->InVertexVisibilityPass)
  {
    mapper->NumberOfElements *= this->NumberOfPointsPerPrimitive;
  }
  else
  {
    mapper->NumberOfElements *= this->NumberOfPseudoPrimitivesPerElement;
  }
  mapper->ShaderProgram->SetUniformi("cellIdOffset", offsets.CellIdOffset);
  mapper->ShaderProgram->SetUniformi("vertexIdOffset", offsets.VertexIdOffset);
  mapper->ShaderProgram->SetUniformi("edgeValueBufferOffset", offsets.EdgeValueBufferOffset);
  mapper->ShaderProgram->SetUniformi("pointIdOffset", offsets.PointIdOffset);
  mapper->ShaderProgram->SetUniformi("primitiveIdOffset", offsets.PrimitiveIdOffset);
  mapper->ShaderProgram->SetUniformi("usesCellMap", cellGroup.UsesCellMapBuffer);
  mapper->ShaderProgram->SetUniformi("usesEdgeValues", cellGroup.UsesEdgeValueBuffer);
  mapper->vtkDrawTexturedElements::DrawInstancedElementsImpl(renderer, actor, mapper);
}

//------------------------------------------------------------------------------
void vtkOpenGLLowMemoryCellTypeAgent::PostDraw(