//example
// open root and give
//root [0] .L test.C
//root [1]  test()
// 
//

//............................................................................
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);

}
//............................................................................
void ShowView(float zoomfactor)
{ 
   gPad->GetView()->ZoomView(0,zoomfactor);
   gPad->SetFillColor(17);//light grey
   gPad->Modified();
   gPad->Update();
}


//............................................................................

//............................................................................

//............................................................................

//............................................................................
   void ShowAxis(float x0=0, float y0=0, float z0=0, float length=4)
   {
      TPolyLine3D *axisX = new TPolyLine3D();
      axisX->SetPoint(0,x0,y0,z0);
      axisX->SetPoint(1,x0+length,y0,z0);
      axisX->SetLineColor(4);//blue
      axisX->SetLineWidth(2);
    
      TPolyLine3D *axisY = new TPolyLine3D();
      axisY->SetPoint(0,x0,y0,z0);
      axisY->SetPoint(1,x0,y0+length,z0);
      axisY->SetLineColor(5);//yellow
      axisY->SetLineWidth(2);
    
      TPolyLine3D *axisZ = new TPolyLine3D();
      axisZ->SetPoint(0,x0,y0,z0);
      axisZ->SetPoint(1,x0,y0,z0+length);
      axisZ->SetLineColor(2);//red
      axisZ->SetLineWidth(2);
    
      axisX->Draw();
      axisY->Draw();
      axisZ->Draw();
   }
//............................................................................
   TNode* BuildLayout()
   {
 
      TNode *mother,*tempNode;

      //
      int   NofWafX      = 3;
      int   NofWafY      = 3;
      int   nCellsPerWaf = 6;//this means 6X6 
      float offsetX      = 7;
      float offsetY      = 7;
      float offsetZ      = 3;
      float x,y,z;
      int   NumOfLayers  = 10; 

      //these are dummy
      TMaterial *mat;     
      TRotMatrix *rot;
      mat = new TMaterial("mat","mat",1.01,1,.0708);
      rot = new TRotMatrix("rot","rot",90,0,90,90,0,0);
      //rot = new TRotMatrix("rot","rot",90,0,180,0,90,90);


      //building blocks
      TBRIK *world = new TBRIK("world","world","mat",100,100,100);
      world->SetVisibility(0);

      TBRIK *cave = new TBRIK("cave","cave","mat",100,100,100);
      cave->SetVisibility(0);

      TBRIK *wafer = new TBRIK("wafer","wafer","mat",3,3,.1);
      wafer->SetLineColor(5);//yellow

      TBRIK *cell = new TBRIK("cell","cell","mat",.5,.5,.05);
      cell->SetLineColor(10);//white
      //cell->SetVisibility(0);
   

      TBRIK *layer = new TBRIK("layer","layer","mat",12,12,1.);
      layer->SetLineColor(15);//grey
      
      TBRIK *block = new TBRIK("block","block","mat",12,12,15);
      block->SetLineColor(1);//black
      
      TBRIK *chamber = new TBRIK("chamber","chamber","mat",18,18,5);
      chamber->SetLineColor(1);//black
      
      
      
      //not used
      TTUBE *hit = new TTUBE("hit","hit","mat",.2,.4,.2);
      hit->SetLineColor(1);//black


      //build geometry nodes = volumes for display 
      
      TNode *test = new TNode("temp","temp","world");
      
      test->cd();
      mother = new TNode("temp","temp","cave",0,0,0,"rot");

      mother->cd();
      for(int iw=0;iw<NofWafX;iw++)
      {  for(int jw=0;jw<NofWafY;jw++)   
         {  for(int k=0; k<NumOfLayers;k++) 
            {  
	       x = offsetX*(iw-1);
	       y = offsetY*(jw-1);
	       z = offsetZ*k;
	       tempNode = new TNode("temp","temp","wafer",x,y,z,"");
            }
         }   
      }
      
      mother->cd();
      for(int i=0+12;i<18;i++)
      {  for(int j=0+12;j<18;j++)   
         {  for(int k=0; k<10;k++) 
            {  
	       //theCell[i][j][k] = new TNode("temp","temp","cell",(8)*(i/6)  + i%6 -3 -8+.5,(8)*(j/6) +j%6-3-8+.5,10*k,"");
	       x = offsetX*(i/nCellsPerWaf - 1)  + i%nCellsPerWaf - wafer->GetDx() + cell->GetDx(); 
	       y = offsetY*(j/nCellsPerWaf - 1)  + j%nCellsPerWaf - wafer->GetDy() + cell->GetDy(); 
	       z = offsetZ*k;
	       tempNode = new TNode("temp","temp","cell",x,y,z,"");
            }
         }   
      }


  
      mother->cd();
      for(int k=0;k<NumOfLayers;k++)
      {  
         x = 0.;
	 y = 0.;
	 z = offsetZ*k;
         tempNode = new TNode("temp","temp","layer",x,y,z,"");
      }

      mother->cd();
      for(int k=0;k<3;k++)
      {  
         x = 0.;
	 y = 0.;
	 z = 30*k+15;
         tempNode = new TNode("temp","temp","block",x,y,z,"");
      }


      mother->cd();
      for(int k=0;k<2;k++)
      {  
         x = 0.;
	 y = 0.;
	 z = 20*k-60;
         tempNode = new TNode("temp","temp","chamber",x,y,z,"");
      }

      //return mother;
      return test;
      

   }