xtruDraw.C

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/// \file
/// \ingroup tutorial_geom
/// Draw a "representative" TXTRU shape
///
/// \macro_image
/// \macro_code
///
/// \author Robert Hatcher (rhatcher@fnal.gov) 2000.09.06
 
void xtruDraw()
{
   TCanvas *canvas = new TCanvas("xtru", "Example XTRU object", 200, 10, 640, 640);
 
   // Create a new geometry
   TGeometry *geometry = new TGeometry("geometry", "geometry");
   geometry->cd();
 
   TXTRU *atxtru = new TXTRU("atxtru", "atxtru", "void", 5, 2);
 
   // outline and z segment specifications
 
   Float_t x[] = {-177.292, -308.432, -308.432, -305.435, -292.456, -280.01, -241.91, -241.91,
                  -177.292, -177.292, 177.292,  177.292,  241.91,   241.91,  280.06,  297.942,
                  305.435,  308.432,  308.432,  177.292,  177.292,  -177.292};
   Float_t y[] = {154.711,  23.5712,  1.1938,  1.1938, 8.6868, 8.6868, -3.7592, -90.0938, -154.711, -190.602, -190.602,
                  -154.711, -90.0938, -3.7592, 8.6868, 8.6868, 1.1938, 1.1938,  23.5712,  154.711,  190.602,  190.602};
   Float_t z[] = {0.00, 500.0};
   Float_t scale[] = {1.00, 1.00};
   Float_t x0[] = {0, 0};
   Float_t y0[] = {0, 0};
 
   Int_t i;
 
   Int_t nxy = sizeof(x) / sizeof(Float_t);
   for (i = 0; i < nxy; i++) {
      atxtru->DefineVertex(i, x[i], y[i]);
   }
 
   Int_t nz = sizeof(z) / sizeof(Float_t);
   for (i = 0; i < nz; i++) {
      atxtru->DefineSection(i, z[i], scale[i], x0[i], y0[i]);
   }
 
   // Define a TNode where this example resides in the TGeometry
   // Draw the TGeometry
 
   TNode *anode = new TNode("anode", "anode", atxtru);
   anode->SetLineColor(1);
 
   geometry->Draw();
 
   // Tweak the pad scales so as not to distort the shape
 
   TVirtualPad *thisPad = gPad;
   if (thisPad) {
      TView *view = thisPad->GetView();
      if (!view)
         return;
      Double_t min[3], max[3], center[3];
      view->GetRange(min, max);
      int i;
      // Find the boxed center
      for (i = 0; i < 3; i++)
         center[i] = 0.5 * (max[i] + min[i]);
      Double_t maxSide = 0;
      // Find the largest side
      for (i = 0; i < 3; i++)
         maxSide = TMath::Max(maxSide, max[i] - center[i]);
   file: // Adjust scales:
      for (i = 0; i < 3; i++) {
         max[i] = center[i] + maxSide;
         min[i] = center[i] - maxSide;
      }
      view->SetRange(min, max);
      Int_t ireply;
      thisPad->Modified();
      thisPad->Update();
   }
}