Method Update

Rendering/VolumeOpenGL2/vtkOpenGLVolumeLookupTable.cxx:129–168

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

//------------------------------------------------------------------------------
void vtkOpenGLVolumeLookupTable::Update(vtkObject* func, double scalarRange[2], int blendMode,
  double sampleDistance, double unitDistance, int filterValue, vtkOpenGLRenderWindow* renWin)
{
  if (!func || !renWin)
  {
    return;
  }

  if (!this->TextureObject)
  {
    this->TextureObject = vtkTextureObject::New();
  }

  this->TextureObject->SetContext(renWin);

  if (this->NeedsUpdate(func, scalarRange, blendMode, sampleDistance))
  {
    int idealW = 1024;
    int newHeight = 1;
    this->ComputeIdealTextureSize(func, idealW, newHeight, renWin);
    int const newWidth = this->GetMaximumSupportedTextureWidth(renWin, idealW);
    if (!this->Table || this->TextureWidth != newWidth || this->TextureHeight != newHeight)
    {
      this->TextureWidth = newWidth;
      this->TextureHeight = newHeight;
      this->AllocateTable();
    }

    this->InternalUpdate(func, blendMode, sampleDistance, unitDistance, filterValue);
    this->LastInterpolation = filterValue;
    this->BuildTime.Modified();
  }

  if (this->LastInterpolation != filterValue)
  {
    this->LastInterpolation = filterValue;
    this->TextureObject->SetMagnificationFilter(filterValue);
    this->TextureObject->SetMinificationFilter(filterValue);
  }
}

//------------------------------------------------------------------------------
void vtkOpenGLVolumeLookupTable::AllocateTable()