Adding some important comments (Laurent)
[u/mrichter/AliRoot.git] / MUON / AliMUONPreClusterFinder.cxx
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18466557 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#include "AliMUONPreClusterFinder.h"
19
20#include "AliLog.h"
21#include "AliMUONCluster.h"
22#include "AliMpVSegmentation.h"
23#include "TClonesArray.h"
24#include "AliMpArea.h"
25#include "TVector2.h"
26#include "AliMUONPad.h"
3887d11e 27#include "AliMUONVDigit.h"
28#include "AliMUONVDigitStore.h"
d592a053 29//#include "AliCodeTimer.h"
18466557 30
31/// \class AliMUONPreClusterFinder
32///
33/// Implementation of AliMUONVClusterFinder
34///
35/// This class simply find adjacent pads to form clusters
36///
37/// \author Laurent Aphecetche
38
39ClassImp(AliMUONPreClusterFinder)
40
41//_____________________________________________________________________________
42AliMUONPreClusterFinder::AliMUONPreClusterFinder()
43: AliMUONVClusterFinder(),
44 fClusters(0x0),
45 fSegmentations(0x0),
18466557 46 fDetElemId(0)
47{
48 /// ctor
49 for ( Int_t i = 0; i < 2; ++i )
50 {
51 fPads[i] = 0x0;
52 }
53}
54
55//_____________________________________________________________________________
56AliMUONPreClusterFinder::~AliMUONPreClusterFinder()
57{
58 /// dtor : note we're owner of the pads and the clusters, but not of
59 /// the remaining objects (digits, segmentations)
60 delete fClusters;
61 for ( Int_t i = 0; i < 2; ++i )
62 {
63 delete fPads[i];
64 }
65}
66
67//_____________________________________________________________________________
68Bool_t
69AliMUONPreClusterFinder::UsePad(const AliMUONPad& pad)
70{
71 /// Add a pad to the list of pads to be considered
72 if ( pad.DetElemId() != fDetElemId )
73 {
74 AliError(Form("Cannot add pad from DE %d to this cluster finder which is "
75 "currently dealing with DE %d",pad.DetElemId(),fDetElemId));
76 return kFALSE;
77 }
78
79 new ((*fPads[pad.Cathode()])[fPads[pad.Cathode()]->GetLast()+1]) AliMUONPad(pad);
80 // FIXME: should set the ClusterId of that new pad to be -1
81 return kTRUE;
82}
83
84//_____________________________________________________________________________
85Bool_t
86AliMUONPreClusterFinder::Prepare(const AliMpVSegmentation* segmentations[2],
3887d11e 87 const AliMUONVDigitStore& digitStore)
18466557 88// FIXME : add area on which to look for clusters here.
89{
90 /// Prepare for clustering, by giving access to segmentations and digit lists
91
92 fSegmentations = segmentations;
18466557 93
94 delete fClusters;
95 fClusters = new TClonesArray("AliMUONCluster");
96 for ( Int_t i = 0; i < 2; ++i )
97 {
98 delete fPads[i];
99 fPads[i] = new TClonesArray("AliMUONPad");
100 }
101
102 fDetElemId = -1;
103
3887d11e 104 TIter next(digitStore.CreateIterator());
105 AliMUONVDigit* d;
106
107 while ( ( d = static_cast<AliMUONVDigit*>(next()) ) )
18466557 108 {
3887d11e 109 Int_t ix = d->PadX();
110 Int_t iy = d->PadY();
111 Int_t cathode = d->Cathode();
112 AliMpPad pad = fSegmentations[cathode]->PadByIndices(AliMpIntPair(ix,iy));
113 TClonesArray& padArray = *(fPads[cathode]);
114 if ( fDetElemId == -1 )
18466557 115 {
3887d11e 116 fDetElemId = d->DetElemId();
117 }
118 else
119 {
120 if ( d->DetElemId() != fDetElemId )
18466557 121 {
3887d11e 122 AliError("Something is seriously wrong with DE. Aborting clustering");
123 return kFALSE;
18466557 124 }
18466557 125 }
3887d11e 126
127 AliMUONPad mpad(fDetElemId,cathode,
128 ix,iy,pad.Position().X(),pad.Position().Y(),
129 pad.Dimensions().X(),pad.Dimensions().Y(),
130 d->Charge());
131 if ( d->IsSaturated() ) mpad.SetSaturated(kTRUE);
132 new (padArray[padArray.GetLast()+1]) AliMUONPad(mpad);
18466557 133 }
134 if ( fPads[0]->GetLast() < 0 && fPads[1]->GetLast() < 0 )
135 {
136 // no pad at all, nothing to do...
137 return kFALSE;
138 }
d592a053 139
18466557 140 return kTRUE;
141}
142
143//_____________________________________________________________________________
144void
145AliMUONPreClusterFinder::AddPad(AliMUONCluster& cluster, AliMUONPad* pad)
146{
147 /// Add a pad to a cluster
148 cluster.AddPad(*pad);
149
150 Int_t cathode = pad->Cathode();
151 TClonesArray& padArray = *fPads[cathode];
d592a053 152 // WARNING: this Remove method uses the AliMUONPad::IsEqual if that method is
153 // present (otherwise just compares pointers) : so that one must be correct
154 // if implemented !
18466557 155 padArray.Remove(pad);
d592a053 156 // TObject* o = padArray.Remove(pad);
157// if (!o)
158// {
159// AliFatal("Oups. Could not remove pad from pads to consider. Aborting as anyway "
160// " we'll get an infinite loop. Please check the AliMUONPad::IsEqual method"
161// " as the first suspect for failed remove");
162// }
18466557 163 TIter next(&padArray);
164 AliMUONPad* testPad;
d592a053 165
18466557 166 while ( ( testPad = static_cast<AliMUONPad*>(next())))
167 {
168 if ( AliMUONPad::AreNeighbours(*testPad,*pad) )
169 {
170 AddPad(cluster,testPad);
171 }
172 }
173}
174
175//_____________________________________________________________________________
176Bool_t
177AreOverlapping(const AliMUONPad& pad, const AliMUONCluster& cluster)
178{
179 /// Whether the pad overlaps with the cluster
180
181 static Double_t precision = 1E-4; // cm
182 static TVector2 precisionAdjustment(precision,precision);//-precision,-precision);
183 for ( Int_t i = 0; i < cluster.Multiplicity(); ++i )
184 {
185 AliMUONPad* testPad = cluster.Pad(i);
186 // Note: we use negative precision numbers, meaning
187 // the area of the pads will be *increased* by these small numbers
188 // prior to check the overlap by the AreOverlapping method,
189 // so pads touching only by the corners will be considered as
190 // overlapping.
191 if ( AliMUONPad::AreOverlapping(*testPad,pad,precisionAdjustment) )
192 {
193 return kTRUE;
194 }
195 }
196 return kFALSE;
197}
198
199//_____________________________________________________________________________
200AliMUONCluster*
201AliMUONPreClusterFinder::NextCluster()
202{
203 /// Builds the next cluster, and returns it.
204
d592a053 205// AliCodeTimerAuto("")
206
18466557 207 // Start a new cluster
208 Int_t id = fClusters->GetLast()+1;
209 AliMUONCluster* cluster = new ((*fClusters)[id]) AliMUONCluster;
210 cluster->SetUniqueID(id);
211
a38d7516 212 TIter next(fPads[0]);
213 AliMUONPad* pad = static_cast<AliMUONPad*>(next());
18466557 214
215 if (!pad) // protection against no pad in first cathode, which might happen
216 {
217 // try other cathode
a38d7516 218 TIter next(fPads[1]);
219 pad = static_cast<AliMUONPad*>(next());
18466557 220 if (!pad)
221 {
222 // we are done.
223 return 0x0;
224 }
225 // Builds (recursively) a cluster on second cathode only
226 AddPad(*cluster,pad);
227 }
228 else
229 {
230 // Builds (recursively) a cluster on first cathode only
231 AddPad(*cluster,pad);
232
233 // On the 2nd cathode, only add pads overlapping with the current cluster
234 TClonesArray& padArray = *fPads[1];
235 TIter next(&padArray);
236 AliMUONPad* testPad;
237
238 while ( ( testPad = static_cast<AliMUONPad*>(next())))
239 {
240 if ( AreOverlapping(*testPad,*cluster) )
241 {
242 AddPad(*cluster,testPad);
243 }
244 }
245 }
246
247 if ( cluster->Multiplicity() <= 1 )
248 {
249 if ( cluster->Multiplicity() == 0 )
250 {
251 // no pad is suspicious
252 AliWarning("Got an empty cluster...");
253 }
254 // else only 1 pad (not suspicious, but kind of useless, probably noise)
255 // so we remove it from our list
256 fClusters->Remove(cluster);
257 fClusters->Compress();
258 // then proceed further
259 return NextCluster();
260 }
261
262 return cluster;
263}