RE: problem with TView zoom

Hi all,
I use both projections. The code looks something like this

   void ShowView(int opt=0)
   {

      theLayout->Draw();


      //gPad->Modified();

      //gPad->Update();

      
      int iret;
      switch(opt)
      {
         case 0:
	   gPad->GetView()->SetPerspective();
	   //gPad->GetView()->SetView(-65,127,-73,iret);
           gPad->GetView()->SetView(-335,127,-73,iret);	   
           gPad->GetView()->ZoomView(0,1.9);
	   break;

	 case 1:
	   gPad->GetView()->SetParallel();
	   gPad->GetView()->SetView(90,180,0,iret);
           gPad->GetView()->ZoomView(0,1.5);
           //gPad->GetView()->Top();
           break;  
      }
      
      gPad->SetFillColor(17);//light grey
      gPad->Modified();
      gPad->Update();

"Zooms" worked as expected with ROOTv4.02.00 or older. With newer versions they do not. As Jan and Olivier suggested a fix is to update the gPad immediately after any TNode::Draw() i.e. after theLayout->Draw();
The gPad->Modified();gPad->Update(); at the last lines do update correctly any rotation, projection, style attribute of the view but not zooms after version 4.02

Regards,
George

On Mon, 20 Feb 2006, Fine, Valeri wrote:

> Can you elaborate what kind of the projection you used Orthographic  or perspective.
>  
> In my mind the default was changed sometimes ago and it must affect the way Zoom method "look and feel"
>  
> Can you toggle the projection  to make sure that may have cured the problem you reported.
> See: 
>  
> http://root.cern.ch/root/htmldoc//src/TView.cxx.html#TView:SetPerspective 
>  
> http://root.cern.ch/root/htmldoc//src/TView.cxx.html#TView:SetParallel
>  
>  
> 
> ________________________________
> 
> From: owner-roottalk_at_pcroot.cern.ch on behalf of G.Mavromanolakis
> Sent: Thu 2/16/2006 5:33 AM
> To: roottalk_at_pcroot.cern.ch
> Cc: gmavroma_at_mail.cern.ch
> Subject: [ROOT] problem with TView zoom
> 
> 
> 
> Hello ROOTers,
> 
> I am developing a 3d event display for a monitor application.
> I used ROOTv4.02.00 under ScientificLinux3 and I tried to switched
> recently to a newer version. I experience some strange behavior from
> the zoom methods in TView class. They work as expected
> when invoked within the CINT or by clicking a TView object on a
> pad. But when they are put in a macro or source code they produce
> no effect.
> For example something like
> 
> void test()
> {
>    TCanvas *c1 = new TCanvas("c1","The ... canvas",200,10,700,700);
>    c1->cd();
> 
>    BuildLayout()->Draw();
>    //ShowAxis(-15,-15,-20,4);
>    ShowView(1.);
> 
>    
>    TCanvas* c2 = new TCanvas("c2","The ... canvas",200,10,700,700);
>    c2->cd();
> 
>    BuildLayout()->Draw();
>    //ShowAxis(-15,-15,-20,4);
>    ShowView(0.5);
> 
> }
> 
> with
> 
> void ShowView(float zoomfactor)
> {
>    gPad->GetView()->ZoomView(0,zoomfactor);
>    gPad->SetFillColor(17);//light grey
>    gPad->Modified();
>    gPad->Update();
> }
> 
> should produce 2 canvases with one normal and one small view.
> This is the case for v4.02.00 or older. When trying with a newer version
> (4.04.02g, 5.08.00) there is no zoom, the example above
> gives 2 identical canvases!
> 
> Also the TView::Zoom, ZoomIn, ZoomOut methods behave similarly
> strange, ie they give no effect. 
> 
> Any hints??? Am I doing something wrong???
> 
> Thanks and regards,
> George
> 
> PS. I attach a small example macro
> (run it from root with
> .L test.C
> test()
> ) 
> 
>