Unneccery repaints are costly

I am using win32gdk v3.10/02. I routinely display TTree’s with several million points. I loop over objects in gPad->GetListOfPrimitives() and call SetBit(kCannotPick) for those that InheritsFrom(“TGraph”)==kTRUE - allows me to mouse over the display and show cursor positions in my statusbar with rapid update otherwise the TGraph selection code consumes all my cpu and cursor postion update is sluggish. (see earlier post)
However, when I click on the display to enter points for my TCutG (actually, wher kButton1Up event is recieved by TCanvas::HandleInput) all of the gPad->GetListOfPrimitives() objects, including the TTree’s TGraph objects (each with 1E6 points) get repainted. Is there a way to avoid these repaints? Thank you.

Hi Ed,
~5 years ago I found solution by overloading
TPad::PaintModified method. Check
TetrisBoard::PaintModified() method.
I hope something “modern and simpler” exist now.

Regards. Valeriy