Method PreDraw

Rendering/OpenGL2/vtkOpenGLLowMemoryCellTypeAgent.cxx:57–114

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//------------------------------------------------------------------------------
void vtkOpenGLLowMemoryCellTypeAgent::PreDraw(
  vtkRenderer* renderer, vtkActor* actor, vtkOpenGLLowMemoryPolyDataMapper* mapper) const
{
  if (!mapper)
  {
    return;
  }
  this->PreDrawInternal(renderer, actor, mapper);
  if (actor->GetProperty()->GetRepresentation() == VTK_POINTS || this->InVertexVisibilityPass)
  {
    mapper->ElementType = vtkDrawTexturedElements::ElementShape::Point;
  }
  // wacky backwards compatibility with old VTK lighting
  // soooo there are many factors that determine if a primitive is lit or not.
  // three that mix in a complex way are representation POINT, Interpolation FLAT
  // and having normals or not.
  bool needLighting = false;
  if (actor->GetProperty()->GetRepresentation() == VTK_POINTS)
  {
    needLighting =
      (actor->GetProperty()->GetInterpolation() != VTK_FLAT && mapper->HasPointNormals);
  }
  else // wireframe or surface rep
  {
    bool isTrisOrStrips = (this->NumberOfPointsPerPrimitive >= 3);
    needLighting = (isTrisOrStrips ||
      (!isTrisOrStrips && actor->GetProperty()->GetInterpolation() != VTK_FLAT &&
        mapper->HasPointNormals));
  }
  if (actor->GetProperty()->GetRenderLinesAsTubes() && actor->GetProperty()->GetLineWidth() > 1.0)
  {
    needLighting = true;
  }
  if (actor->GetProperty()->GetRenderPointsAsSpheres() &&
    mapper->ElementType == vtkDrawTexturedElements::ElementShape::Point)
  {
    needLighting = true;
  }
  mapper->ShaderProgram->SetUniformi("enable_lights", needLighting);
  mapper->ShaderProgram->SetUniformi("vertex_pass", this->InVertexVisibilityPass);
  switch (mapper->ElementType)
  {
    case vtkDrawTexturedElements::ElementShape::Point:
      mapper->ShaderProgram->SetUniformi("primitiveSize", 1);
      break;
    case vtkDrawTexturedElements::ElementShape::Line:
      mapper->ShaderProgram->SetUniformi("primitiveSize", 2);
      break;
    case vtkDrawTexturedElements::ElementShape::Triangle:
    default:
      mapper->ShaderProgram->SetUniformi("primitiveSize", 3);
      break;
  }
  mapper->ShaderProgram->SetUniformf("pointSize",
    mapper->PointPicking ? ::GetPointPickingPrimitiveSize(mapper->ElementType)
                         : actor->GetProperty()->GetPointSize());
  mapper->vtkDrawTexturedElements::PreDraw(renderer, actor, mapper);
}