SimpleDiskBounds.cc

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#include "DataFormats/GeometrySurface/interface/SimpleDiskBounds.h"
#include "DataFormats/GeometrySurface/interface/LocalError.h" 
#include <algorithm>
#include <cmath>

SimpleDiskBounds::SimpleDiskBounds( float rmin, float rmax, float zmin, float zmax) : 
  theRmin(rmin), theRmax(rmax), theZmin(zmin), theZmax(zmax) {
  if ( theRmin > theRmax) std::swap( theRmin, theRmax);
  if ( theZmin > theZmax) std::swap( theZmin, theZmax);
}

bool SimpleDiskBounds::inside( const Local3DPoint& p) const {
  return p.z()    > theZmin && p.z()    < theZmax &&
    p.perp() > theRmin && p.perp() < theRmax;
}
    
bool SimpleDiskBounds::inside( const Local2DPoint& p, const LocalError& err) const {
  return Bounds::inside(p,err);
}

Bounds* SimpleDiskBounds::clone() const { 
  return new SimpleDiskBounds(*this);
}



bool SimpleDiskBounds::inside( const Local3DPoint& p, const LocalError& err, float scale) const 
{
  if (p.z() < theZmin || p.z() > theZmax) return false; // check the easy part first
  
  double perp2 = p.perp2();
  double perp = sqrt(perp2);
  if (perp2 == 0) return scale*scale*(err.xx() + err.xy())  > theRmin*theRmin;
  
  // rotated error along p.x(),p.y()
  // equivalent to (but faster than) err.rotate(p.x(),p.y()).xx()
  // since we don't need all matrix elements
  float deltaR = scale * sqrt( p.x()*p.x()/perp2 * err.xx() - 
                   2*p.x()*p.y()/perp2 * err.xy() + 
                   p.y()*p.y()/perp2 * err.yy());
  return perp > std::max(theRmin-deltaR, 0.f) && perp < theRmax+deltaR;
}