TPaveText and TH2 have different Drawing behaviour

ROOT
1

Dear all,

I noticed that if I mistakenly draw again an again the same TPaveText, the canvas becomes sluggish.

Proof:

TCanvas c
pt = new TPaveText(0.78,0.63,0.98,0.83,"brNDC");
pt->Draw()
TStopwatch w 
w.Reset() ; w.Start(); c.Update() ; w.Stop(); w.Print("u"); // here it says something really small
for(int i = 0 ; i < 100000 ; i++) {
   pt->Draw();
}
w.Reset() ; w.Start(); c.Update() ; w.Stop(); w.Print("u"); // here it says something bigger

Interestingly, if you save the canvas as a Macro you can see the 100000 pave text instantiated. In the canvas though, there is only 1 TPaveText.

I tried to reproduce the same behaviour with an histogram but couldn’t. The histograms behave as I expected: drawing the same thing several times doesn’t change anything (it is the same pointer added to the same list,correct?).

Is it on purpose that the TPaveText behaves differently ?
If not, I think that it would be worth fixing it. For me it took quite some time to find out why my canvas was becoming slower and slower.

Cheers,
Barth

2

I’ll check

3

Solved by phone