Method UpdateShadingTable

Rendering/Volume/vtkEncodedGradientShader.cxx:180–350

}

void vtkEncodedGradientShader::UpdateShadingTable(
  vtkRenderer* ren, vtkVolume* vol, vtkEncodedGradientEstimator* gradest)
{
  double lightDirection[3], material[4];
  double lightAmbientColor[3];
  double lightDiffuseColor[3];
  double lightSpecularColor[3];
  double lightPosition[3], lightFocalPoint[3];
  double lightIntensity, viewDirection[3];
  double cameraPosition[3], cameraFocalPoint[3], mag;
  vtkLightCollection* lightCollection;
  vtkLight* light;
  double norm;
  int update_flag;
  vtkVolumeProperty* property;
  vtkTransform* transform;
  vtkMatrix4x4* m;
  double in[4], out[4], zero[4];
  int index;

  // Figure out which shading table we are working with
  // First search through all existing ones, then if one
  // is not found, use the first available index
  for (index = 0; index < VTK_MAX_SHADING_TABLES; index++)
  {
    if (this->ShadingTableVolume[index] == vol)
    {
      break;
    }
  }

  if (index == VTK_MAX_SHADING_TABLES)
  {
    for (index = 0; index < VTK_MAX_SHADING_TABLES; index++)
    {
      if (this->ShadingTableVolume[index] == nullptr)
      {
        this->ShadingTableVolume[index] = vol;
        break;
      }
    }
  }
  if (index == VTK_MAX_SHADING_TABLES)
  {
    vtkErrorMacro(<< "Too many shading tables!\n"
                  << "Increase limit VTK_MAX_SHADING_TABLES and recompile!");
    return;
  }

  transform = vtkTransform::New();
  m = vtkMatrix4x4::New();

  vol->GetMatrix(m);
  transform->SetMatrix(m);
  transform->Inverse();

  property = vol->GetProperty();