If you mean scrolling the graph to the left and then updating the pixels on the right, then I have done something similar at a lower level.
What I did was shift the entire window to the left by one pixel i.e by manipulating the contents of the frame-buffer directly. I then added the new pixel to the right of the graph. Produced a nice scrolling effect, was smooth and did't need to erase the existing pixels as shifting the memory did that automatically. Could do multiple graphs as without addin extra overhead.
Toughgfx didn't have to know about it
Hope this helps
