[831] | 1 | // |
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| 2 | // ******************************************************************** |
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| 3 | // * License and Disclaimer * |
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| 4 | // * * |
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| 5 | // * The Geant4 software is copyright of the Copyright Holders of * |
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| 6 | // * the Geant4 Collaboration. It is provided under the terms and * |
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| 7 | // * conditions of the Geant4 Software License, included in the file * |
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| 8 | // * LICENSE and available at http://cern.ch/geant4/license . These * |
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| 9 | // * include a list of copyright holders. * |
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| 10 | // * * |
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| 11 | // * Neither the authors of this software system, nor their employing * |
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| 12 | // * institutes,nor the agencies providing financial support for this * |
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| 13 | // * work make any representation or warranty, express or implied, * |
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| 14 | // * regarding this software system or assume any liability for its * |
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| 15 | // * use. Please see the license in the file LICENSE and URL above * |
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| 16 | // * for the full disclaimer and the limitation of liability. * |
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| 17 | // * * |
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| 18 | // * This code implementation is the result of the scientific and * |
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| 19 | // * technical work of the GEANT4 collaboration. * |
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| 20 | // * By using, copying, modifying or distributing the software (or * |
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| 21 | // * any work based on the software) you agree to acknowledge its * |
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| 22 | // * use in resulting scientific publications, and indicate your * |
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| 23 | // * acceptance of all terms of the Geant4 Software license. * |
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| 24 | // ******************************************************************** |
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| 25 | // |
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| 26 | // |
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| 27 | // $Id: G4ReduciblePolygon.cc,v 1.11 2006/06/29 18:48:53 gunter Exp $ |
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[850] | 28 | // GEANT4 tag $Name: HEAD $ |
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[831] | 29 | // |
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| 30 | // |
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| 31 | // -------------------------------------------------------------------- |
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| 32 | // GEANT 4 class source file |
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| 33 | // |
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| 34 | // |
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| 35 | // G4ReduciblePolygon.cc |
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| 36 | // |
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| 37 | // Implementation of a utility class used to specify, test, reduce, |
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| 38 | // and/or otherwise manipulate a 2D polygon. |
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| 39 | // |
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| 40 | // See G4ReduciblePolygon.hh for more info. |
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| 41 | // |
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| 42 | // -------------------------------------------------------------------- |
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| 43 | |
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| 44 | #include "G4ReduciblePolygon.hh" |
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| 45 | #include "globals.hh" |
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| 46 | |
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| 47 | // |
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| 48 | // Constructor: with simple arrays |
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| 49 | // |
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| 50 | G4ReduciblePolygon::G4ReduciblePolygon( const G4double a[], |
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| 51 | const G4double b[], |
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| 52 | G4int n ) |
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| 53 | : aMin(0.), aMax(0.), bMin(0.), bMax(0.), |
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| 54 | vertexHead(0) |
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| 55 | { |
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| 56 | // |
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| 57 | // Do all of the real work in Create |
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| 58 | // |
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| 59 | Create( a, b, n ); |
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| 60 | } |
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| 61 | |
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| 62 | |
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| 63 | // |
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| 64 | // Constructor: special PGON/PCON case |
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| 65 | // |
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| 66 | G4ReduciblePolygon::G4ReduciblePolygon( const G4double rmin[], |
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| 67 | const G4double rmax[], |
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| 68 | const G4double z[], G4int n ) |
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| 69 | : aMin(0.), aMax(0.), bMin(0.), bMax(0.), |
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| 70 | vertexHead(0) |
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| 71 | { |
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| 72 | // |
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| 73 | // Translate |
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| 74 | // |
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| 75 | G4double *a = new G4double[n*2]; |
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| 76 | G4double *b = new G4double[n*2]; |
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| 77 | |
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| 78 | G4double *rOut = a + n, |
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| 79 | *zOut = b + n, |
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| 80 | *rIn = rOut-1, |
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| 81 | *zIn = zOut-1; |
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| 82 | |
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| 83 | G4int i; |
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| 84 | for( i=0; i < n; i++, rOut++, zOut++, rIn--, zIn-- ) |
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| 85 | { |
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| 86 | *rOut = rmax[i]; |
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| 87 | *rIn = rmin[i]; |
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| 88 | *zOut = *zIn = z[i]; |
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| 89 | } |
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| 90 | |
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| 91 | Create( a, b, n*2 ); |
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| 92 | |
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| 93 | delete [] a; |
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| 94 | delete [] b; |
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| 95 | } |
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| 96 | |
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| 97 | |
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| 98 | // |
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| 99 | // Create |
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| 100 | // |
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| 101 | // To be called by constructors, fill in the list and statistics for a new |
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| 102 | // polygon |
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| 103 | // |
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| 104 | void G4ReduciblePolygon::Create( const G4double a[], |
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| 105 | const G4double b[], G4int n ) |
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| 106 | { |
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| 107 | if (n<3) |
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| 108 | G4Exception("G4ReduciblePolygon::Create()", "WrongArgumentValue", |
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| 109 | FatalException, "Less than 3 vertices specified."); |
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| 110 | |
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| 111 | const G4double *anext = a, *bnext = b; |
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| 112 | ABVertex *prev = 0; |
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| 113 | do |
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| 114 | { |
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| 115 | ABVertex *newVertex = new ABVertex; |
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| 116 | newVertex->a = *anext; |
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| 117 | newVertex->b = *bnext; |
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| 118 | newVertex->next = 0; |
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| 119 | if (prev==0) |
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| 120 | { |
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| 121 | vertexHead = newVertex; |
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| 122 | } |
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| 123 | else |
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| 124 | { |
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| 125 | prev->next = newVertex; |
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| 126 | } |
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| 127 | |
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| 128 | prev = newVertex; |
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| 129 | } while( ++anext, ++bnext < b+n ); |
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| 130 | |
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| 131 | numVertices = n; |
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| 132 | |
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| 133 | CalculateMaxMin(); |
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| 134 | } |
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| 135 | |
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| 136 | |
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| 137 | // |
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| 138 | // Fake default constructor - sets only member data and allocates memory |
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| 139 | // for usage restricted to object persistency. |
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| 140 | // |
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| 141 | G4ReduciblePolygon::G4ReduciblePolygon( __void__& ) |
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| 142 | : aMin(0.), aMax(0.), bMin(0.), bMax(0.), vertexHead(0) |
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| 143 | { |
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| 144 | } |
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| 145 | |
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| 146 | |
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| 147 | // |
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| 148 | // Destructor |
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| 149 | // |
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| 150 | G4ReduciblePolygon::~G4ReduciblePolygon() |
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| 151 | { |
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| 152 | ABVertex *curr = vertexHead; |
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| 153 | while( curr ) |
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| 154 | { |
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| 155 | ABVertex *toDelete = curr; |
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| 156 | curr = curr->next; |
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| 157 | delete toDelete; |
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| 158 | } |
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| 159 | } |
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| 160 | |
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| 161 | |
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| 162 | // |
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| 163 | // CopyVertices |
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| 164 | // |
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| 165 | // Copy contents into simple linear arrays. |
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| 166 | // ***** CAUTION ***** Be care to declare the arrays to a large |
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| 167 | // enough size! |
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| 168 | // |
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| 169 | void G4ReduciblePolygon::CopyVertices( G4double a[], G4double b[] ) const |
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| 170 | { |
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| 171 | G4double *anext = a, *bnext = b; |
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| 172 | ABVertex *curr = vertexHead; |
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| 173 | while( curr ) |
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| 174 | { |
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| 175 | *anext++ = curr->a; |
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| 176 | *bnext++ = curr->b; |
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| 177 | curr = curr->next; |
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| 178 | } |
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| 179 | } |
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| 180 | |
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| 181 | |
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| 182 | // |
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| 183 | // ScaleA |
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| 184 | // |
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| 185 | // Multiply all a values by a common scale |
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| 186 | // |
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| 187 | void G4ReduciblePolygon::ScaleA( G4double scale ) |
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| 188 | { |
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| 189 | ABVertex *curr = vertexHead; |
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| 190 | while( curr ) |
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| 191 | { |
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| 192 | curr->a *= scale; |
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| 193 | curr = curr->next; |
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| 194 | } |
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| 195 | } |
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| 196 | |
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| 197 | |
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| 198 | // |
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| 199 | // ScaleB |
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| 200 | // |
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| 201 | // Multiply all b values by a common scale |
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| 202 | // |
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| 203 | void G4ReduciblePolygon::ScaleB( G4double scale ) |
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| 204 | { |
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| 205 | ABVertex *curr = vertexHead; |
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| 206 | while( curr ) |
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| 207 | { |
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| 208 | curr->b *= scale; |
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| 209 | curr = curr->next; |
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| 210 | } |
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| 211 | } |
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| 212 | |
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| 213 | |
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| 214 | // |
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| 215 | // RemoveDuplicateVertices |
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| 216 | // |
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| 217 | // Remove adjacent vertices that are equal. Returns "false" if there |
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| 218 | // is a problem (too few vertices remaining). |
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| 219 | // |
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| 220 | G4bool G4ReduciblePolygon::RemoveDuplicateVertices( G4double tolerance ) |
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| 221 | { |
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| 222 | ABVertex *curr = vertexHead, |
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| 223 | *prev = 0, |
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| 224 | *next = curr->next; // A little dangerous |
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| 225 | while( curr ) |
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| 226 | { |
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| 227 | next = curr->next; |
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| 228 | if (next == 0) next = vertexHead; |
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| 229 | |
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| 230 | if (std::fabs(curr->a-next->a) < tolerance && |
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| 231 | std::fabs(curr->b-next->b) < tolerance ) |
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| 232 | { |
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| 233 | // |
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| 234 | // Duplicate found: do we have > 3 vertices? |
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| 235 | // |
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| 236 | if (numVertices <= 3) |
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| 237 | { |
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| 238 | CalculateMaxMin(); |
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| 239 | return false; |
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| 240 | } |
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| 241 | |
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| 242 | // |
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| 243 | // Delete |
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| 244 | // |
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| 245 | ABVertex *toDelete = curr; |
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| 246 | curr = curr->next; |
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| 247 | delete toDelete; |
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| 248 | |
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| 249 | numVertices--; |
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| 250 | |
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| 251 | if (prev) prev->next = curr; else vertexHead = curr; |
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| 252 | } |
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| 253 | else |
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| 254 | { |
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| 255 | prev = curr; |
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| 256 | curr = curr->next; |
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| 257 | } |
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| 258 | } |
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| 259 | |
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| 260 | // |
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| 261 | // In principle, this is not needed, but why not just play it safe? |
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| 262 | // |
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| 263 | CalculateMaxMin(); |
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| 264 | |
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| 265 | return true; |
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| 266 | } |
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| 267 | |
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| 268 | |
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| 269 | // |
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| 270 | // RemoveRedundantVertices |
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| 271 | // |
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| 272 | // Remove any unneeded vertices, i.e. those vertices which |
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| 273 | // are on the line connecting the previous and next vertices. |
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| 274 | // |
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| 275 | G4bool G4ReduciblePolygon::RemoveRedundantVertices( G4double tolerance ) |
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| 276 | { |
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| 277 | // |
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| 278 | // Under these circumstances, we can quit now! |
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| 279 | // |
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| 280 | if (numVertices <= 2) return false; |
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| 281 | |
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| 282 | G4double tolerance2 = tolerance*tolerance; |
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| 283 | |
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| 284 | // |
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| 285 | // Loop over all vertices |
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| 286 | // |
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| 287 | ABVertex *curr = vertexHead, |
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| 288 | *next = curr->next; // A little dangerous |
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| 289 | while( curr ) |
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| 290 | { |
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| 291 | next = curr->next; |
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| 292 | if (next == 0) next = vertexHead; |
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| 293 | |
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| 294 | G4double da = next->a - curr->a, |
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| 295 | db = next->b - curr->b; |
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| 296 | |
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| 297 | // |
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| 298 | // Loop over all subsequent vertices, up to curr |
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| 299 | // |
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| 300 | for(;;) |
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| 301 | { |
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| 302 | // |
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| 303 | // Get vertex after next |
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| 304 | // |
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| 305 | ABVertex *test = next->next; |
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| 306 | if (test == 0) test = vertexHead; |
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| 307 | |
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| 308 | // |
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| 309 | // If we are back to the original vertex, stop |
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| 310 | // |
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| 311 | if (test==curr) break; |
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| 312 | |
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| 313 | // |
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| 314 | // Test for parallel line segments |
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| 315 | // |
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| 316 | G4double dat = test->a - curr->a, |
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| 317 | dbt = test->b - curr->b; |
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| 318 | |
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| 319 | if (std::fabs(dat*db-dbt*da)>tolerance2) break; |
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| 320 | |
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| 321 | // |
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| 322 | // Redundant vertex found: do we have > 3 vertices? |
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| 323 | // |
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| 324 | if (numVertices <= 3) |
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| 325 | { |
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| 326 | CalculateMaxMin(); |
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| 327 | return false; |
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| 328 | } |
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| 329 | |
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| 330 | // |
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| 331 | // Delete vertex pointed to by next. Carefully! |
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| 332 | // |
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| 333 | if (curr->next) |
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| 334 | { // next is not head |
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| 335 | if (next->next) |
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| 336 | curr->next = test; // next is not tail |
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| 337 | else |
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| 338 | curr->next = 0; // New tail |
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| 339 | } |
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| 340 | else |
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| 341 | vertexHead = test; // New head |
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| 342 | |
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| 343 | delete next; |
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| 344 | |
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| 345 | numVertices--; |
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| 346 | |
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| 347 | // |
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| 348 | // Replace next by the vertex we just tested, |
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| 349 | // and keep on going... |
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| 350 | // |
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| 351 | next = test; |
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| 352 | da = dat; db = dbt; |
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| 353 | } |
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| 354 | curr = curr->next; |
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| 355 | } |
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| 356 | |
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| 357 | // |
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| 358 | // In principle, this is not needed, but why not just play it safe? |
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| 359 | // |
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| 360 | CalculateMaxMin(); |
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| 361 | |
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| 362 | return true; |
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| 363 | } |
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| 364 | |
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| 365 | |
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| 366 | // |
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| 367 | // ReverseOrder |
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| 368 | // |
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| 369 | // Reverse the order of the vertices |
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| 370 | // |
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| 371 | void G4ReduciblePolygon::ReverseOrder() |
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| 372 | { |
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| 373 | // |
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| 374 | // Loop over all vertices |
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| 375 | // |
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| 376 | ABVertex *prev = vertexHead; |
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| 377 | if (prev==0) return; // No vertices |
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| 378 | |
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| 379 | ABVertex *curr = prev->next; |
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| 380 | if (curr==0) return; // Just one vertex |
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| 381 | |
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| 382 | // |
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| 383 | // Our new tail |
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| 384 | // |
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| 385 | vertexHead->next = 0; |
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| 386 | |
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| 387 | for(;;) |
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| 388 | { |
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| 389 | // |
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| 390 | // Save pointer to next vertex (in original order) |
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| 391 | // |
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| 392 | ABVertex *save = curr->next; |
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| 393 | |
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| 394 | // |
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| 395 | // Replace it with a pointer to the previous one |
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| 396 | // (in original order) |
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| 397 | // |
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| 398 | curr->next = prev; |
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| 399 | |
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| 400 | // |
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| 401 | // Last vertex? |
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| 402 | // |
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| 403 | if (save == 0) break; |
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| 404 | |
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| 405 | // |
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| 406 | // Next vertex |
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| 407 | // |
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| 408 | prev = curr; |
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| 409 | curr = save; |
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| 410 | } |
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| 411 | |
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| 412 | // |
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| 413 | // Our new head |
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| 414 | // |
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| 415 | vertexHead = curr; |
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| 416 | } |
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| 417 | |
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| 418 | |
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| 419 | // |
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| 420 | // CrossesItself |
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| 421 | // |
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| 422 | // Return "true" if the polygon crosses itself |
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| 423 | // |
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| 424 | // Warning: this routine is not very fast (runs as N**2) |
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| 425 | // |
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| 426 | G4bool G4ReduciblePolygon::CrossesItself( G4double tolerance ) |
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| 427 | { |
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| 428 | G4double tolerance2 = tolerance*tolerance; |
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| 429 | G4double one = 1.0-tolerance, |
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| 430 | zero = tolerance; |
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| 431 | // |
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| 432 | // Top loop over line segments. By the time we finish |
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| 433 | // with the second to last segment, we're done. |
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| 434 | // |
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| 435 | ABVertex *curr1 = vertexHead, *next1=0; |
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| 436 | while (curr1->next) { |
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| 437 | next1 = curr1->next; |
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| 438 | G4double da1 = next1->a-curr1->a, |
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| 439 | db1 = next1->b-curr1->b; |
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| 440 | |
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| 441 | // |
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| 442 | // Inner loop over subsequent line segments |
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| 443 | // |
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| 444 | ABVertex *curr2 = next1->next; |
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| 445 | while( curr2 ) { |
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| 446 | ABVertex *next2 = curr2->next; |
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| 447 | if (next2==0) next2 = vertexHead; |
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| 448 | G4double da2 = next2->a-curr2->a, |
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| 449 | db2 = next2->b-curr2->b; |
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| 450 | G4double a12 = curr2->a-curr1->a, |
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| 451 | b12 = curr2->b-curr1->b; |
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| 452 | |
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| 453 | // |
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| 454 | // Calculate intersection of the two lines |
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| 455 | // |
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| 456 | G4double deter = da1*db2 - db1*da2; |
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| 457 | if (std::fabs(deter) > tolerance2) { |
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| 458 | G4double s1, s2; |
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| 459 | s1 = (a12*db2-b12*da2)/deter; |
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| 460 | |
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| 461 | if (s1 >= zero && s1 < one) { |
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| 462 | s2 = -(da1*b12-db1*a12)/deter; |
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| 463 | if (s2 >= zero && s2 < one) return true; |
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| 464 | } |
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| 465 | } |
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| 466 | curr2 = curr2->next; |
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| 467 | } |
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| 468 | curr1 = next1; |
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| 469 | } |
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| 470 | return false; |
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| 471 | } |
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| 472 | |
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| 473 | |
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| 474 | |
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| 475 | // |
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| 476 | // BisectedBy |
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| 477 | // |
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| 478 | // Decide if a line through two points crosses the polygon, within tolerance |
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| 479 | // |
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| 480 | G4bool G4ReduciblePolygon::BisectedBy( G4double a1, G4double b1, |
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| 481 | G4double a2, G4double b2, |
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| 482 | G4double tolerance ) |
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| 483 | { |
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| 484 | G4int nNeg = 0, nPos = 0; |
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| 485 | |
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| 486 | G4double a12 = a2-a1, b12 = b2-b1; |
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| 487 | G4double len12 = std::sqrt( a12*a12 + b12*b12 ); |
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| 488 | a12 /= len12; b12 /= len12; |
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| 489 | |
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| 490 | ABVertex *curr = vertexHead; |
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| 491 | do |
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| 492 | { |
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| 493 | G4double av = curr->a - a1, |
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| 494 | bv = curr->b - b1; |
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| 495 | |
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| 496 | G4double cross = av*b12 - bv*a12; |
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| 497 | |
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| 498 | if (cross < -tolerance) |
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| 499 | { |
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| 500 | if (nPos) return true; |
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| 501 | nNeg++; |
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| 502 | } |
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| 503 | else if (cross > tolerance) |
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| 504 | { |
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| 505 | if (nNeg) return true; |
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| 506 | nPos++; |
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| 507 | } |
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| 508 | curr = curr->next; |
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| 509 | } while( curr ); |
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| 510 | |
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| 511 | return false; |
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| 512 | } |
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| 513 | |
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| 514 | |
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| 515 | |
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| 516 | // |
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| 517 | // Area |
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| 518 | // |
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| 519 | // Calculated signed polygon area, where polygons specified in a |
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| 520 | // clockwise manner (where x==a, y==b) have negative area |
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| 521 | // |
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| 522 | // References: [O' Rourke (C)] pp. 18-27; [Gems II] pp. 5-6: |
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| 523 | // "The Area of a Simple Polygon", Jon Rokne. |
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| 524 | // |
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| 525 | G4double G4ReduciblePolygon::Area() |
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| 526 | { |
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| 527 | G4double answer = 0; |
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| 528 | |
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| 529 | ABVertex *curr = vertexHead, *next; |
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| 530 | do |
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| 531 | { |
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| 532 | next = curr->next; |
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| 533 | if (next==0) next = vertexHead; |
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| 534 | |
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| 535 | answer += curr->a*next->b - curr->b*next->a; |
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| 536 | curr = curr->next; |
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| 537 | } while( curr ); |
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| 538 | |
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| 539 | return 0.5*answer; |
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| 540 | } |
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| 541 | |
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| 542 | |
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| 543 | // |
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| 544 | // Print |
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| 545 | // |
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| 546 | void G4ReduciblePolygon::Print() |
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| 547 | { |
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| 548 | ABVertex *curr = vertexHead; |
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| 549 | do |
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| 550 | { |
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| 551 | G4cerr << curr->a << " " << curr->b << G4endl; |
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| 552 | curr = curr->next; |
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| 553 | } while( curr ); |
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| 554 | } |
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| 555 | |
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| 556 | |
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| 557 | // |
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| 558 | // CalculateMaxMin |
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| 559 | // |
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| 560 | // To be called when the vertices are changed, this |
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| 561 | // routine re-calculates global values |
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| 562 | // |
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| 563 | void G4ReduciblePolygon::CalculateMaxMin() |
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| 564 | { |
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| 565 | ABVertex *curr = vertexHead; |
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| 566 | aMin = aMax = curr->a; |
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| 567 | bMin = bMax = curr->b; |
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| 568 | curr = curr->next; |
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| 569 | while( curr ) |
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| 570 | { |
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| 571 | if (curr->a < aMin) |
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| 572 | aMin = curr->a; |
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| 573 | else if (curr->a > aMax) |
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| 574 | aMax = curr->a; |
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| 575 | |
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| 576 | if (curr->b < bMin) |
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| 577 | bMin = curr->b; |
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| 578 | else if (curr->b > bMax) |
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| 579 | bMax = curr->b; |
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| 580 | |
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| 581 | curr = curr->next; |
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| 582 | } |
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| 583 | } |
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