[u/mrichter/AliRoot.git] / MUON / AliMUONContourMaker.cxx

/**************************************************************************
* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
*                                                                        *
* Author: The ALICE Off-line Project.                                    *
* Contributors are mentioned in the code where appropriate.              *
*                                                                        *
* Permission to use, copy, modify and distribute this software and its   *
* documentation strictly for non-commercial purposes is hereby granted   *
* without fee, provided that the above copyright notice appears in all   *
* copies and that both the copyright notice and this permission notice   *
* appear in the supporting documentation. The authors make no claims     *
* about the suitability of this software for any purpose. It is          *
* provided "as is" without express or implied warranty.                  *
**************************************************************************/

// $Id$

///
/// Maker/merger of contours. Can create contour from a set polygons or
/// merger a set of contours into a single one.
/// 
/// This is based on (one of the) algorithm found in 
/// Diane L. Souvaine and Iliana Bjorling-Sachs,
/// Proceedings of the IEEE, Vol. 80, No. 9, September 1992, p. 1449
///
/// Note that besides the AliMUON prefix, nothing is really MUON specific
/// in this class...
///
/// \author Laurent Aphecetche, Subatech
///

#include "AliMUONContourMaker.h"

#include "AliCodeTimer.h"
#include "AliLog.h"
#include "AliMUONContour.h"
#include "AliMUONPointWithRef.h"
#include "AliMUONPolygon.h"
#include "AliMUONSegment.h"
#include "AliMUONSegmentTree.h"
#include "Riostream.h"
#include "TArrayD.h"
#include "TMath.h"
#include <cassert>

/// \cond CLASSIMP
ClassImp(AliMUONContourMaker)
/// \endcond

namespace
{
  void PrintSegments(const TObjArray& array)
  {
    TIter next(&array);
    AliMUONSegment* s;
    Int_t i(0);
    while ( ( s = static_cast<AliMUONSegment*>(next()) ) )
    {
      cout << Form("i=%d %s",i,s->AsString()) << endl;
      ++i;
    }
  }
}

//_____________________________________________________________________________
AliMUONContourMaker::AliMUONContourMaker() 
{
/// Default constructor
}


//_____________________________________________________________________________
AliMUONContourMaker::~AliMUONContourMaker()
{
/// Destructor
}

//_____________________________________________________________________________
AliMUONContour* 
AliMUONContourMaker::CreateContour(const TObjArray& polygons, const char* name) const
{
  /// Create the contour of the polygon array
  /// and get back the intermediate verticals and horizontal segments
  /// both arrays are arrays of AliMUONSegment objects.
  
  AliCodeTimerAuto("");
  
  if ( polygons.IsEmpty() ) return 0x0; // protection against user error...
  
  // Sanity check : insure that all polygons are oriented counter-clockwise
  TIter next(&polygons);
  AliMUONPolygon* pol;
  while ( ( pol = static_cast<AliMUONPolygon*>(next()) ) )
  {
    if ( !pol->IsCounterClockwiseOriented() )
    {
      AliError(Form("Got a clockwise oriented polygon in CreateContour(%s). That's not OK !",name));
      StdoutToAliError(polygons.Print());
      return 0x0;
    }
  }
  
  AliMUONContour* contour(0x0);
  
  if ( polygons.GetLast() == 0 ) 
  {
    AliCodeTimerAuto("Trivial case");
    contour = new AliMUONContour(name);
    pol = static_cast<const AliMUONPolygon*>(polygons.First());
    contour->Add(*pol);
    contour->AssertOrientation();
    return contour;
  }
  
  TObjArray polygonVerticalEdges; // arrray of AliMUONSegment objects  
  polygonVerticalEdges.SetOwner(kTRUE);
  // get vertical edges of input polygons
  GetVerticalEdges(polygons,polygonVerticalEdges);
  
  // sort them in ascending x order
  // if same x, insure that left edges are before right edges
  // within same x, order by increasing bottommost y (see AliMUONSegment::Compare method)
  polygonVerticalEdges.Sort();
  
  if ( polygonVerticalEdges.GetLast()+1 < 2 ) 
  {
    AliError(Form("Got too few edges here for createContour %s",name));
    polygons.Print();
    TObject* o(0x0);
    o->Print();
  }
  
  // Find the vertical edges of the merged contour. This is the meat of the algorithm...
  TObjArray contourVerticalEdges;
  contourVerticalEdges.SetOwner(kTRUE);
  Sweep(polygonVerticalEdges,contourVerticalEdges);
  
  TObjArray horizontals;
  horizontals.SetOwner(kTRUE);
  VerticalToHorizontal(contourVerticalEdges,horizontals);
  
  contour = FinalizeContour(contourVerticalEdges,horizontals);
  
  if ( contour && name ) contour->SetName(name);
  
  return contour;
}

//_____________________________________________________________________________
AliMUONContour* 
AliMUONContourMaker::FinalizeContour(const TObjArray& verticals,
                                     const TObjArray& horizontals) const
{  
  /// For a list of vertical and horizontal edges, we build the final
  /// contour object.
  
  AliCodeTimerAuto("");
  
  TObjArray all; // array of AliMUONSegment
  TObjArray inorder; // array of AliMUONSegment

  all.SetOwner(kFALSE);
  inorder.SetOwner(kFALSE);
    
  for ( Int_t i = 0; i <= verticals.GetLast(); ++i ) 
  {
    all.Add(verticals.UncheckedAt(i));
    all.Add(horizontals.UncheckedAt(i));
  }
  
  Int_t i(0);
  
  AliMUONContour* contour = new AliMUONContour;
  
  int total(0);
  
  while ( !all.IsEmpty() )
  {
    total++;
    
    if ( total > 1000 ) 
    {
      AliError("Total 1000 reached !!!!");
      return 0x0;
    }
    
    AliMUONSegment* si = static_cast<AliMUONSegment*>(all.UncheckedAt(i));
    inorder.Add(si);
    const AliMUONSegment* all0 = static_cast<const AliMUONSegment*>(all.First());
    if ( i != 0 && AliMUONSegment::AreEqual(si->EndX(),all0->StartX()) && AliMUONSegment::AreEqual(si->EndY(),all0->StartY()) )
    {
      Int_t n(-1);
      
      AliMUONPolygon polygon(inorder.GetLast()+2);

      // we got a cycle. Add it to the contour
      for ( Int_t j = 0; j <= inorder.GetLast(); ++j ) 
      {
        AliMUONSegment* s = static_cast<AliMUONSegment*>(inorder.UncheckedAt(j));
        polygon.SetVertex(++n,s->StartX(),s->StartY());
        all.Remove(s);
      }
      
      all.Compress();

      polygon.Close();
      
      contour->Add(polygon);
      
      if ( ! all.IsEmpty() )
      {
        i = 0;
        inorder.Clear();
      }
      continue;
    }
    
    for ( Int_t j = 0; j <= all.GetLast(); ++j) 
    {
      if ( j != i ) 
      {        
        const AliMUONSegment* sj = static_cast<const AliMUONSegment*>(all.UncheckedAt(j));
        if ( AliMUONSegment::AreEqual(si->EndX(),sj->StartX()) && AliMUONSegment::AreEqual(si->EndY(),sj->StartY()))
        {
          i = j;
          break;
        }
      }
    }    
  }
  
  contour->AssertOrientation(kTRUE);
  return contour;
}


//_____________________________________________________________________________
void 
AliMUONContourMaker::GetVerticalEdges(const TObjArray& polygons, TObjArray& polygonVerticalEdges) const
{
  /// From an array of polygons, extract the list of vertical edges.
  /// Output array polygonVerticalEdges should be empty before calling.
  
  AliCodeTimerAuto("");
  
  for ( Int_t i = 0; i <= polygons.GetLast(); ++i ) 
  {
    const AliMUONPolygon* g = static_cast<const AliMUONPolygon*>(polygons.UncheckedAt(i));
    for ( Int_t j = 0; j < g->NumberOfVertices()-1; ++j ) 
    {
      if ( AliMUONSegment::AreEqual(g->X(j),g->X(j+1)) ) // segment is vertical
      {
        polygonVerticalEdges.Add(new AliMUONSegment(g->X(j),g->Y(j),g->X(j+1),g->Y(j+1)));
      }
    }
  }
}


//_____________________________________________________________________________
void
AliMUONContourMaker::GetYPositions(const TObjArray& polygonVerticalEdges,
                                   TArrayD& yPositions) const
{
  /// Fill the array yPositions with the different y positions found in 
  /// polygonVerticalEdges
  
  AliCodeTimerAuto("");
  
  Double_t* y = new Double_t[polygonVerticalEdges.GetSize()*2];
  Int_t n(0);
  
  for ( Int_t i = 0; i < polygonVerticalEdges.GetLast(); ++i ) 
  {
    AliMUONSegment* s = static_cast<AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i));
    y[n] = s->StartY();
    y[n+1] = s->EndY();
    n += 2;
  }
  Int_t* ix = new Int_t[n+1];
  
  TMath::Sort(n,y,ix,kFALSE);
  
  yPositions.Set(n+1);
  
  Int_t u(0);
  Double_t x(FLT_MAX);
  
  for ( Int_t i = 0; i < n; ++i ) 
  {
    if ( y[ix[i]] != x )
    {
      yPositions[u] = y[ix[i]];
      x = y[ix[i]];
      ++u;
    }
  }

  yPositions.Set(u);
  
  delete[] ix;
  delete[] y;
  
}

//_____________________________________________________________________________
AliMUONContour* 
AliMUONContourMaker::MergeContour(const TObjArray& contours, const char* name) const
{
  /// Merge all the polygons of all contours into a single contour
  
  AliCodeTimerAuto("");
  
  TObjArray polygons;
  polygons.SetOwner(kTRUE);
  
  TIter next(&contours);
  AliMUONContour* contour;
  while ( ( contour = static_cast<AliMUONContour*>(next()) ) )
  {
    const TObjArray* contourPolygons = contour->Polygons();
    TIter nextPol(contourPolygons);
    AliMUONPolygon* pol;
    while ( ( pol = static_cast<AliMUONPolygon*>(nextPol()) ) )
    {
      polygons.Add(new AliMUONPolygon(*pol));
    }
  }
  
  if ( polygons.IsEmpty() ) return 0x0;
  
  contour = CreateContour(polygons,name);
  
  return contour;
}

//_____________________________________________________________________________
void 
AliMUONContourMaker::SortPoints(const TObjArray& polygonVerticalEdges, 
                                TObjArray& sortedPoints) const
{
  /// Sort the point of the vertical edges in ascending order, first on ordinate, 
  /// then on abcissa, and put them in output vector sortedPoints.
  /// Output array sortedPoints should be empty before calling this method.
  
  AliCodeTimerAuto("");
  
  for ( Int_t i = 0; i <= polygonVerticalEdges.GetLast(); ++i )
  {
    const AliMUONSegment* e = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i));
    sortedPoints.Add(new AliMUONPointWithRef(e->StartX(),e->StartY(),i));
    sortedPoints.Add(new AliMUONPointWithRef(e->EndX(),e->EndY(),i));
    // note that we keep track of the original edge, which is used
    // later on to deduce orientation of horizontal edges.
  }
  
  sortedPoints.Sort(); 
}

//_____________________________________________________________________________
void 
AliMUONContourMaker::Sweep(const TObjArray& polygonVerticalEdges, 
                           TObjArray& contourVerticalEdges) const
{
  /// This is the meat of the algorithm of the contour merging...
  
  AliCodeTimerAuto("");
  
  TArrayD yPositions;
  GetYPositions(polygonVerticalEdges,yPositions);
  
  AliMUONSegmentTree segmentTree(yPositions);
  
  for ( Int_t i = 0; i <= polygonVerticalEdges.GetLast(); ++i )
  {
    const AliMUONSegment* edge = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i));
    
    assert(edge!=0x0);
    
    if ( edge->IsLeftEdge() ) 
    {
      segmentTree.Contribution(edge->Bottom(),edge->Top());
      segmentTree.InsertInterval(edge->Bottom(),edge->Top());
    }
    else
    {
      segmentTree.DeleteInterval(edge->Bottom(),edge->Top());
      segmentTree.Contribution(edge->Bottom(),edge->Top());
    }
    
    AliMUONSegment e1(*edge);
    
    if ( i < polygonVerticalEdges.GetLast() ) 
    {
      const AliMUONSegment* next = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i+1));
      e1 = *next;
    }

    if ( ( edge->IsLeftEdge() != e1.IsLeftEdge() ) ||
        ( !AliMUONSegment::AreEqual(edge->StartX(),e1.StartX() ) ) ||
        ( i == polygonVerticalEdges.GetLast() ) )
    {
      const TObjArray& stack = segmentTree.Stack();
      
      double x = edge->StartX();
      
      for ( Int_t j = 0; j <= stack.GetLast(); ++j )
      {
        AliMUONSegment* sj = static_cast<AliMUONSegment*>(stack.UncheckedAt(j));
        AliMUONSegment* s = new AliMUONSegment(x,sj->StartY(),x,sj->EndY());
        
        if  (s->IsAPoint()) 
        {
          delete s;
          continue;
        }
        
        if ( edge->IsLeftEdge() != s->IsLeftEdge() ) 
        {
          s->Set(x,sj->EndY(),x,sj->StartY());
        }
        contourVerticalEdges.Add(s);
      }
      segmentTree.ResetStack();
    }
  }
}

//_____________________________________________________________________________
void 
AliMUONContourMaker::VerticalToHorizontal(const TObjArray& polygonVerticalEdges,
                                          TObjArray& horizontalEdges) const
{
  /// Deduce the set of horizontal edges from the vertical edges
  /// Output array horizontalEdges should be empty before calling this method
  
  AliCodeTimerAuto("");
  
  TObjArray points; // array of AliMUONPointWithRef
  points.SetOwner(kTRUE);
  
  SortPoints(polygonVerticalEdges,points);
  
  for ( Int_t k = 0; k < (points.GetLast()+1)/2; ++k )
  {
    const AliMUONPointWithRef* p1 = static_cast<AliMUONPointWithRef*>(points.UncheckedAt(k*2));
    const AliMUONPointWithRef* p2 = static_cast<AliMUONPointWithRef*>(points.UncheckedAt(k*2+1));
    
    const AliMUONSegment* refEdge = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(p1->Ref()));
    
    // (p1,p2) is the horizontal edge.
    // refEdge is used to deduce the orientation of (p1,p2)
    
    if ( AliMUONSegment::AreEqual(p1->X(),refEdge->EndX()) && AliMUONSegment::AreEqual(p1->Y(),refEdge->EndY()) )
//    if ( AreEqual(p1,refEdge->End()) )
    {
      horizontalEdges.Add(new AliMUONSegment(p1->X(),p1->Y(),p2->X(),p2->Y()));
    }
    else
    {
      horizontalEdges.Add(new AliMUONSegment(p2->X(),p2->Y(),p1->X(),p1->Y()));
    }
  }
}
Commit	Line	Data
0b936dc0	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15
	16	// $Id$
	17
	18	///
	19	/// Maker/merger of contours. Can create contour from a set polygons or
	20	/// merger a set of contours into a single one.
	21	///
	22	/// This is based on (one of the) algorithm found in
	23	/// Diane L. Souvaine and Iliana Bjorling-Sachs,
	24	/// Proceedings of the IEEE, Vol. 80, No. 9, September 1992, p. 1449
	25	///
	26	/// Note that besides the AliMUON prefix, nothing is really MUON specific
	27	/// in this class...
	28	///
	29	/// \author Laurent Aphecetche, Subatech
	30	///
	31
	32	#include "AliMUONContourMaker.h"
	33
	34	#include "AliCodeTimer.h"
	35	#include "AliLog.h"
	36	#include "AliMUONContour.h"
	37	#include "AliMUONPointWithRef.h"
	38	#include "AliMUONPolygon.h"
	39	#include "AliMUONSegment.h"
	40	#include "AliMUONSegmentTree.h"
	41	#include "Riostream.h"
	42	#include "TArrayD.h"
	43	#include "TMath.h"
	44	#include <cassert>
	45
	46	/// \cond CLASSIMP
	47	ClassImp(AliMUONContourMaker)
	48	/// \endcond
	49
	50	namespace
	51	{
	52	void PrintSegments(const TObjArray& array)
	53	{
	54	TIter next(&array);
	55	AliMUONSegment* s;
	56	Int_t i(0);
	57	while ( ( s = static_cast<AliMUONSegment*>(next()) ) )
	58	{
	59	cout << Form("i=%d %s",i,s->AsString()) << endl;
	60	++i;
	61	}
	62	}
	63	}
	64
65	//_____________________________________________________________________________
66	AliMUONContourMaker::AliMUONContourMaker()
67	{
cddcc1f3	68	/// Default constructor
0b936dc0	69	}
0b936dc0	70
cddcc1f3	71
0b936dc0	72	//_____________________________________________________________________________
	73	AliMUONContourMaker::~AliMUONContourMaker()
	74	{
cddcc1f3	75	/// Destructor
0b936dc0	76	}
	77
	78	//_____________________________________________________________________________
	79	AliMUONContour*
	80	AliMUONContourMaker::CreateContour(const TObjArray& polygons, const char* name) const
	81	{
	82	/// Create the contour of the polygon array
	83	/// and get back the intermediate verticals and horizontal segments
	84	/// both arrays are arrays of AliMUONSegment objects.
	85
	86	AliCodeTimerAuto("");
	87
	88	if ( polygons.IsEmpty() ) return 0x0; // protection against user error...
	89
	90	// Sanity check : insure that all polygons are oriented counter-clockwise
	91	TIter next(&polygons);
	92	AliMUONPolygon* pol;
	93	while ( ( pol = static_cast<AliMUONPolygon*>(next()) ) )
	94	{
	95	if ( !pol->IsCounterClockwiseOriented() )
	96	{
	97	AliError(Form("Got a clockwise oriented polygon in CreateContour(%s). That's not OK !",name));
	98	StdoutToAliError(polygons.Print());
	99	return 0x0;
	100	}
	101	}
	102
	103	AliMUONContour* contour(0x0);
	104
	105	if ( polygons.GetLast() == 0 )
	106	{
	107	AliCodeTimerAuto("Trivial case");
	108	contour = new AliMUONContour(name);
	109	pol = static_cast<const AliMUONPolygon*>(polygons.First());
	110	contour->Add(*pol);
	111	contour->AssertOrientation();
	112	return contour;
	113	}
	114
	115	TObjArray polygonVerticalEdges; // arrray of AliMUONSegment objects
	116	polygonVerticalEdges.SetOwner(kTRUE);
	117	// get vertical edges of input polygons
	118	GetVerticalEdges(polygons,polygonVerticalEdges);
	119
	120	// sort them in ascending x order
	121	// if same x, insure that left edges are before right edges
	122	// within same x, order by increasing bottommost y (see AliMUONSegment::Compare method)
	123	polygonVerticalEdges.Sort();
	124
	125	if ( polygonVerticalEdges.GetLast()+1 < 2 )
	126	{
	127	AliError(Form("Got too few edges here for createContour %s",name));
	128	polygons.Print();
	129	TObject* o(0x0);
	130	o->Print();
	131	}
	132
	133	// Find the vertical edges of the merged contour. This is the meat of the algorithm...
	134	TObjArray contourVerticalEdges;
	135	contourVerticalEdges.SetOwner(kTRUE);
	136	Sweep(polygonVerticalEdges,contourVerticalEdges);
	137
	138	TObjArray horizontals;
	139	horizontals.SetOwner(kTRUE);
140	VerticalToHorizontal(contourVerticalEdges,horizontals);
141
142	contour = FinalizeContour(contourVerticalEdges,horizontals);
143
144	if ( contour && name ) contour->SetName(name);
145
146	return contour;
147	}
148
149	//_____________________________________________________________________________
150	AliMUONContour*
151	AliMUONContourMaker::FinalizeContour(const TObjArray& verticals,
152	const TObjArray& horizontals) const
153	{
154	/// For a list of vertical and horizontal edges, we build the final
155	/// contour object.
156
157	AliCodeTimerAuto("");
158
159	TObjArray all; // array of AliMUONSegment
160	TObjArray inorder; // array of AliMUONSegment
161
162	all.SetOwner(kFALSE);
163	inorder.SetOwner(kFALSE);
164
165	for ( Int_t i = 0; i <= verticals.GetLast(); ++i )
166	{
167	all.Add(verticals.UncheckedAt(i));
168	all.Add(horizontals.UncheckedAt(i));
169	}
170
171	Int_t i(0);
172
173	AliMUONContour* contour = new AliMUONContour;
174
175	int total(0);
176
177	while ( !all.IsEmpty() )
178	{
179	total++;
180
181	if ( total > 1000 )
182	{
183	AliError("Total 1000 reached !!!!");
184	return 0x0;
185	}
186
187	AliMUONSegment* si = static_cast<AliMUONSegment*>(all.UncheckedAt(i));
188	inorder.Add(si);
189	const AliMUONSegment* all0 = static_cast<const AliMUONSegment*>(all.First());
190	if ( i != 0 && AliMUONSegment::AreEqual(si->EndX(),all0->StartX()) && AliMUONSegment::AreEqual(si->EndY(),all0->StartY()) )
191	{
192	Int_t n(-1);
193
194	AliMUONPolygon polygon(inorder.GetLast()+2);
195
196	// we got a cycle. Add it to the contour
197	for ( Int_t j = 0; j <= inorder.GetLast(); ++j )
198	{
199	AliMUONSegment* s = static_cast<AliMUONSegment*>(inorder.UncheckedAt(j));
200	polygon.SetVertex(++n,s->StartX(),s->StartY());
201	all.Remove(s);
202	}
203
204	all.Compress();
205
206	polygon.Close();
207
208	contour->Add(polygon);
209
210	if ( ! all.IsEmpty() )
211	{
212	i = 0;
213	inorder.Clear();
214	}
215	continue;
216	}
217
218	for ( Int_t j = 0; j <= all.GetLast(); ++j)
219	{
220	if ( j != i )
221	{
222	const AliMUONSegment* sj = static_cast<const AliMUONSegment*>(all.UncheckedAt(j));
223	if ( AliMUONSegment::AreEqual(si->EndX(),sj->StartX()) && AliMUONSegment::AreEqual(si->EndY(),sj->StartY()))
224	{
225	i = j;
226	break;
227	}
228	}
229	}
230	}
231
232	contour->AssertOrientation(kTRUE);
233	return contour;
234	}
235
236
237	//_____________________________________________________________________________
238	void
239	AliMUONContourMaker::GetVerticalEdges(const TObjArray& polygons, TObjArray& polygonVerticalEdges) const
240	{
241	/// From an array of polygons, extract the list of vertical edges.
242	/// Output array polygonVerticalEdges should be empty before calling.
243
244	AliCodeTimerAuto("");
245
246	for ( Int_t i = 0; i <= polygons.GetLast(); ++i )
247	{
248	const AliMUONPolygon* g = static_cast<const AliMUONPolygon*>(polygons.UncheckedAt(i));
249	for ( Int_t j = 0; j < g->NumberOfVertices()-1; ++j )
250	{
251	if ( AliMUONSegment::AreEqual(g->X(j),g->X(j+1)) ) // segment is vertical
252	{
253	polygonVerticalEdges.Add(new AliMUONSegment(g->X(j),g->Y(j),g->X(j+1),g->Y(j+1)));
254	}
255	}
256	}
257	}
258
259
260	//_____________________________________________________________________________
261	void
262	AliMUONContourMaker::GetYPositions(const TObjArray& polygonVerticalEdges,
263	TArrayD& yPositions) const
264	{
265	/// Fill the array yPositions with the different y positions found in
266	/// polygonVerticalEdges
267
268	AliCodeTimerAuto("");
269
270	Double_t* y = new Double_t[polygonVerticalEdges.GetSize()*2];
271	Int_t n(0);
272
273	for ( Int_t i = 0; i < polygonVerticalEdges.GetLast(); ++i )
274	{
275	AliMUONSegment* s = static_cast<AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i));
276	y[n] = s->StartY();
277	y[n+1] = s->EndY();
278	n += 2;
279	}
280	Int_t* ix = new Int_t[n+1];
281
282	TMath::Sort(n,y,ix,kFALSE);
283
284	yPositions.Set(n+1);
285
286	Int_t u(0);
287	Double_t x(FLT_MAX);
288
289	for ( Int_t i = 0; i < n; ++i )
290	{
291	if ( y[ix[i]] != x )
292	{
293	yPositions[u] = y[ix[i]];
294	x = y[ix[i]];
295	++u;
296	}
297	}
298
299	yPositions.Set(u);
300
301	delete[] ix;
302	delete[] y;
303
304	}
305
306	//_____________________________________________________________________________
307	AliMUONContour*
308	AliMUONContourMaker::MergeContour(const TObjArray& contours, const char* name) const
309	{
310	/// Merge all the polygons of all contours into a single contour
311
312	AliCodeTimerAuto("");
313
314	TObjArray polygons;
315	polygons.SetOwner(kTRUE);
316
317	TIter next(&contours);
318	AliMUONContour* contour;
319	while ( ( contour = static_cast<AliMUONContour*>(next()) ) )
320	{
321	const TObjArray* contourPolygons = contour->Polygons();
322	TIter nextPol(contourPolygons);
323	AliMUONPolygon* pol;
324	while ( ( pol = static_cast<AliMUONPolygon*>(nextPol()) ) )
325	{
326	polygons.Add(new AliMUONPolygon(*pol));
327	}
328	}
329
330	if ( polygons.IsEmpty() ) return 0x0;
331
332	contour = CreateContour(polygons,name);
333
334	return contour;
335	}
336
337	//_____________________________________________________________________________
338	void
339	AliMUONContourMaker::SortPoints(const TObjArray& polygonVerticalEdges,
340	TObjArray& sortedPoints) const
341	{
342	/// Sort the point of the vertical edges in ascending order, first on ordinate,
343	/// then on abcissa, and put them in output vector sortedPoints.
344	/// Output array sortedPoints should be empty before calling this method.
345
346	AliCodeTimerAuto("");
347
348	for ( Int_t i = 0; i <= polygonVerticalEdges.GetLast(); ++i )
349	{
350	const AliMUONSegment* e = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i));
351	sortedPoints.Add(new AliMUONPointWithRef(e->StartX(),e->StartY(),i));
352	sortedPoints.Add(new AliMUONPointWithRef(e->EndX(),e->EndY(),i));
353	// note that we keep track of the original edge, which is used
354	// later on to deduce orientation of horizontal edges.
355	}
356
357	sortedPoints.Sort();
358	}
359
360	//_____________________________________________________________________________
361	void
362	AliMUONContourMaker::Sweep(const TObjArray& polygonVerticalEdges,
363	TObjArray& contourVerticalEdges) const
364	{
365	/// This is the meat of the algorithm of the contour merging...
366
367	AliCodeTimerAuto("");
368
369	TArrayD yPositions;
370	GetYPositions(polygonVerticalEdges,yPositions);
371
372	AliMUONSegmentTree segmentTree(yPositions);
373
374	for ( Int_t i = 0; i <= polygonVerticalEdges.GetLast(); ++i )
375	{
376	const AliMUONSegment* edge = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i));
377
378	assert(edge!=0x0);
379
380	if ( edge->IsLeftEdge() )
381	{
382	segmentTree.Contribution(edge->Bottom(),edge->Top());
383	segmentTree.InsertInterval(edge->Bottom(),edge->Top());
384	}
385	else
386	{
387	segmentTree.DeleteInterval(edge->Bottom(),edge->Top());
388	segmentTree.Contribution(edge->Bottom(),edge->Top());
389	}
390
391	AliMUONSegment e1(*edge);
392
393	if ( i < polygonVerticalEdges.GetLast() )
394	{
395	const AliMUONSegment* next = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(i+1));
396	e1 = *next;
397	}
398
399	if ( ( edge->IsLeftEdge() != e1.IsLeftEdge() ) \|\|
400	( !AliMUONSegment::AreEqual(edge->StartX(),e1.StartX() ) ) \|\|
401	( i == polygonVerticalEdges.GetLast() ) )
402	{
403	const TObjArray& stack = segmentTree.Stack();
404
405	double x = edge->StartX();
406
407	for ( Int_t j = 0; j <= stack.GetLast(); ++j )
408	{
409	AliMUONSegment* sj = static_cast<AliMUONSegment*>(stack.UncheckedAt(j));
410	AliMUONSegment* s = new AliMUONSegment(x,sj->StartY(),x,sj->EndY());
411
412	if (s->IsAPoint())
413	{
414	delete s;
415	continue;
416	}
417
418	if ( edge->IsLeftEdge() != s->IsLeftEdge() )
419	{
420	s->Set(x,sj->EndY(),x,sj->StartY());
421	}
422	contourVerticalEdges.Add(s);
423	}
424	segmentTree.ResetStack();
425	}
426	}
427	}
428
429	//_____________________________________________________________________________
430	void
431	AliMUONContourMaker::VerticalToHorizontal(const TObjArray& polygonVerticalEdges,
432	TObjArray& horizontalEdges) const
433	{
434	/// Deduce the set of horizontal edges from the vertical edges
435	/// Output array horizontalEdges should be empty before calling this method
436
437	AliCodeTimerAuto("");
438
439	TObjArray points; // array of AliMUONPointWithRef
440	points.SetOwner(kTRUE);
441
442	SortPoints(polygonVerticalEdges,points);
443
444	for ( Int_t k = 0; k < (points.GetLast()+1)/2; ++k )
445	{
446	const AliMUONPointWithRef* p1 = static_cast<AliMUONPointWithRef>(points.UncheckedAt(k2));
447	const AliMUONPointWithRef* p2 = static_cast<AliMUONPointWithRef>(points.UncheckedAt(k2+1));
448
449	const AliMUONSegment* refEdge = static_cast<const AliMUONSegment*>(polygonVerticalEdges.UncheckedAt(p1->Ref()));
450
451	// (p1,p2) is the horizontal edge.
452	// refEdge is used to deduce the orientation of (p1,p2)
453
454	if ( AliMUONSegment::AreEqual(p1->X(),refEdge->EndX()) && AliMUONSegment::AreEqual(p1->Y(),refEdge->EndY()) )
455	// if ( AreEqual(p1,refEdge->End()) )
456	{
457	horizontalEdges.Add(new AliMUONSegment(p1->X(),p1->Y(),p2->X(),p2->Y()));
458	}
459	else
460	{
461	horizontalEdges.Add(new AliMUONSegment(p2->X(),p2->Y(),p1->X(),p1->Y()));
462	}
463	}
464	}
465