Adding MUONChamberMaterialBudget.C:
[u/mrichter/AliRoot.git] / MUON / AliMUONSegment.cxx
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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/// \class AliMUONSegment
19///
20/// A basic line segment, to be used in contour making algorithms.
21///
22/// In particular, this class defines what a left or right edge is.
23///
24/// Also, please note that, due to the way Root collections are sorted (relying
25/// on TObject::Compare method), the way the AliMUONSegment::Compare method
26/// is implemented below is really important when it comes to understand
27/// contour making algorithm. Keep that in mind.
28///
29/// \author Laurent Aphecetche, Subatech
30///
31
32#include "AliMUONSegment.h"
33
34#include "TMath.h"
35#include "Riostream.h"
36#include "AliMpConstants.h"
37
38/// \cond CLASSIMP
39ClassImp(AliMUONSegment)
40/// \endcond
41
42const Double_t AliMUONSegment::fgkPrecision(AliMpConstants::LengthTolerance());
43
44//_____________________________________________________________________________
45AliMUONSegment::AliMUONSegment() :
46TObject(),
47fStartX(), fStartY(), fEndX(), fEndY(), fSmallerY(), fIsHorizontal(), fIsVertical(),
48fIsLeftEdge(), fIsRightEdge(), fIsAPoint(kTRUE)
49{
50 /// Ctor
51 Set(fStartX,fStartY,fEndX,fEndY);
52}
53
54//_____________________________________________________________________________
55AliMUONSegment::AliMUONSegment(Double_t xstart, Double_t ystart, Double_t xend, Double_t yend)
56: TObject(),
57fStartX(xstart), fStartY(ystart), fEndX(xend), fEndY(yend), fSmallerY(), fIsHorizontal(), fIsVertical(),
58fIsLeftEdge(), fIsRightEdge(), fIsAPoint(kTRUE)
59{
60 /// Ctor
61 Set(xstart,ystart,xend,yend);
62}
63
64//_____________________________________________________________________________
65Bool_t
66AliMUONSegment::AreEqual(double a, double b)
67{
68 /// Whether the two floats are equal within the given precision
69 return (TMath::Abs(b-a) < fgkPrecision);
70}
71
72//_____________________________________________________________________________
73Int_t
74AliMUONSegment::Compare(const TObject* obj) const
75{
76 /// Compare method, which sort segments in ascending x order
77 /// if same x, insure that left edges are before right edges
78 /// within same x, order by increasing bottommost y
79 /// Mind your steps ! This method is critical to the contour merging algorithm !
80
81 const AliMUONSegment* rhs = static_cast<const AliMUONSegment*>(obj);
82
83 if ( AreEqual(StartX(),rhs->StartX()) )
84 {
85 if ( IsLeftEdge() && rhs->IsRightEdge() ) return -1;
86 if ( IsRightEdge() && rhs->IsLeftEdge() ) return 1;
87 if ( SmallerY() < rhs->SmallerY() ) return -1;
88 if ( SmallerY() > rhs->SmallerY() ) return 1;
89 return 0;
90 }
91 else if ( StartX() < rhs->StartX() )
92 {
93 return -1;
94 }
95 else //if ( StartX() > rhs->StartX() )
96 {
97 return 1;
98 }
99}
100
101//_____________________________________________________________________________
102double AliMUONSegment::Top() const
103{
104 /// Max Y of the segment
105 return TMath::Max(fStartY,fEndY);
106}
107
108//_____________________________________________________________________________
109double AliMUONSegment::Distance() const
110{
111 /// Length of the segment
112 return TMath::Sqrt((fStartX-fEndX)*(fStartX-fEndX) +
113 (fStartY-fEndY)*(fStartY-fEndY));
114}
115
116//_____________________________________________________________________________
117void AliMUONSegment::Print(Option_t*) const
118{
119 /// Printout
120 cout << AsString() << endl;
121}
122
123//_____________________________________________________________________________
124const char* AliMUONSegment::AsString() const
125{
126 /// Return a string representation of this object
127 return Form("[ (%10.5f,%10.5f) -> (%10.5f,%10.5f) %s ] (d=%e)",fStartX,fStartY,fEndX,fEndY,
128 IsLeftEdge() ? "L" : ( IsRightEdge() ? "R" : ( IsHorizontal() ? "H" : "" )),
129 Distance() );
130}
131
132//_____________________________________________________________________________
133void
134AliMUONSegment::Set(Double_t xstart, Double_t ystart, Double_t xend, Double_t yend)
135{
136 /// Set start and end point, and (re)compute internal values
137 fStartX = xstart;
138 fEndX = xend;
139 fStartY = ystart;
140 fEndY = yend;
141 fSmallerY = TMath::Min(fStartY,fEndY);
142 fIsHorizontal = AreEqual(fStartY,fEndY);
143 fIsVertical = AreEqual(fStartX,fEndX);
144 fIsLeftEdge = fIsVertical && ( fStartY > fEndY );
145 fIsRightEdge = fIsVertical && ( fStartY < fEndY );
146 fIsAPoint = ( Distance() < fgkPrecision );
147}
148