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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 | |
39 | ClassImp(AliMUONSegment) | |
40 | /// \endcond | |
41 | ||
42 | const Double_t AliMUONSegment::fgkPrecision(AliMpConstants::LengthTolerance()); | |
43 | ||
44 | //_____________________________________________________________________________ | |
45 | AliMUONSegment::AliMUONSegment() : | |
46 | TObject(), | |
47 | fStartX(), fStartY(), fEndX(), fEndY(), fSmallerY(), fIsHorizontal(), fIsVertical(), | |
48 | fIsLeftEdge(), fIsRightEdge(), fIsAPoint(kTRUE) | |
49 | { | |
50 | /// Ctor | |
51 | Set(fStartX,fStartY,fEndX,fEndY); | |
52 | } | |
53 | ||
54 | //_____________________________________________________________________________ | |
55 | AliMUONSegment::AliMUONSegment(Double_t xstart, Double_t ystart, Double_t xend, Double_t yend) | |
56 | : TObject(), | |
57 | fStartX(xstart), fStartY(ystart), fEndX(xend), fEndY(yend), fSmallerY(), fIsHorizontal(), fIsVertical(), | |
58 | fIsLeftEdge(), fIsRightEdge(), fIsAPoint(kTRUE) | |
59 | { | |
60 | /// Ctor | |
61 | Set(xstart,ystart,xend,yend); | |
62 | } | |
63 | ||
64 | //_____________________________________________________________________________ | |
65 | Bool_t | |
66 | AliMUONSegment::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 | //_____________________________________________________________________________ | |
73 | Int_t | |
74 | AliMUONSegment::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 | //_____________________________________________________________________________ | |
102 | double AliMUONSegment::Top() const | |
103 | { | |
104 | /// Max Y of the segment | |
105 | return TMath::Max(fStartY,fEndY); | |
106 | } | |
107 | ||
108 | //_____________________________________________________________________________ | |
109 | double 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 | //_____________________________________________________________________________ | |
117 | void AliMUONSegment::Print(Option_t*) const | |
118 | { | |
119 | /// Printout | |
120 | cout << AsString() << endl; | |
121 | } | |
122 | ||
123 | //_____________________________________________________________________________ | |
124 | const 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 | //_____________________________________________________________________________ | |
133 | void | |
134 | AliMUONSegment::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 |