[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: G4ClippablePolygon.cc,v 1.12 2007/05/11 13:54:28 gcosmo 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 | // G4ClippablePolygon.cc |
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| 36 | // |
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| 37 | // Includes code from G4VSolid (P.Kent, V.Grichine, J.Allison) |
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| 38 | // |
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| 39 | // -------------------------------------------------------------------- |
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| 40 | |
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| 41 | #include "G4ClippablePolygon.hh" |
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| 42 | |
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| 43 | #include "G4VoxelLimits.hh" |
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| 44 | #include "G4GeometryTolerance.hh" |
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| 45 | |
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| 46 | // |
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| 47 | // Constructor |
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| 48 | // |
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| 49 | G4ClippablePolygon::G4ClippablePolygon() |
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| 50 | : normal(0.,0.,0.) |
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| 51 | { |
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| 52 | kCarTolerance = G4GeometryTolerance::GetInstance()->GetSurfaceTolerance(); |
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| 53 | } |
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| 54 | |
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| 55 | |
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| 56 | // |
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| 57 | // Destructor |
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| 58 | // |
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| 59 | G4ClippablePolygon::~G4ClippablePolygon() |
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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 | // |
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| 65 | // AddVertexInOrder |
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| 66 | // |
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| 67 | void G4ClippablePolygon::AddVertexInOrder( const G4ThreeVector vertex ) |
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| 68 | { |
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| 69 | vertices.push_back( vertex ); |
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| 70 | } |
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| 71 | |
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| 72 | |
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| 73 | // |
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| 74 | // ClearAllVertices |
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| 75 | // |
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| 76 | void G4ClippablePolygon::ClearAllVertices() |
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| 77 | { |
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| 78 | vertices.clear(); |
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| 79 | } |
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| 80 | |
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| 81 | |
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| 82 | // |
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| 83 | // Clip |
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| 84 | // |
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| 85 | G4bool G4ClippablePolygon::Clip( const G4VoxelLimits &voxelLimit ) |
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| 86 | { |
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| 87 | if (voxelLimit.IsLimited()) { |
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| 88 | ClipAlongOneAxis( voxelLimit, kXAxis ); |
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| 89 | ClipAlongOneAxis( voxelLimit, kYAxis ); |
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| 90 | ClipAlongOneAxis( voxelLimit, kZAxis ); |
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| 91 | } |
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| 92 | |
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| 93 | return (vertices.size() > 0); |
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| 94 | } |
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| 95 | |
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| 96 | |
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| 97 | // |
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| 98 | // PartialClip |
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| 99 | // |
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| 100 | // Clip, while ignoring the indicated axis |
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| 101 | // |
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| 102 | G4bool G4ClippablePolygon::PartialClip( const G4VoxelLimits &voxelLimit, |
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| 103 | const EAxis IgnoreMe ) |
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| 104 | { |
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| 105 | if (voxelLimit.IsLimited()) { |
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| 106 | if (IgnoreMe != kXAxis) ClipAlongOneAxis( voxelLimit, kXAxis ); |
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| 107 | if (IgnoreMe != kYAxis) ClipAlongOneAxis( voxelLimit, kYAxis ); |
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| 108 | if (IgnoreMe != kZAxis) ClipAlongOneAxis( voxelLimit, kZAxis ); |
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| 109 | } |
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| 110 | |
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| 111 | return (vertices.size() > 0); |
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| 112 | } |
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| 113 | |
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| 114 | |
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| 115 | // |
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| 116 | // GetExtent |
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| 117 | // |
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| 118 | G4bool G4ClippablePolygon::GetExtent( const EAxis axis, |
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| 119 | G4double &min, |
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| 120 | G4double &max ) const |
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| 121 | { |
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| 122 | // |
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| 123 | // Okay, how many entries do we have? |
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| 124 | // |
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| 125 | G4int noLeft = vertices.size(); |
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| 126 | |
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| 127 | // |
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| 128 | // Return false if nothing is left |
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| 129 | // |
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| 130 | if (noLeft == 0) return false; |
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| 131 | |
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| 132 | // |
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| 133 | // Initialize min and max to our first vertex |
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| 134 | // |
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| 135 | min = max = vertices[0].operator()( axis ); |
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| 136 | |
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| 137 | // |
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| 138 | // Compare to the rest |
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| 139 | // |
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| 140 | G4int i; |
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| 141 | for( i=1; i<noLeft; i++ ) |
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| 142 | { |
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| 143 | G4double component = vertices[i].operator()( axis ); |
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| 144 | if (component < min ) |
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| 145 | min = component; |
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| 146 | else if (component > max ) |
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| 147 | max = component; |
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| 148 | } |
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| 149 | |
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| 150 | return true; |
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| 151 | } |
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| 152 | |
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| 153 | |
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| 154 | // |
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| 155 | // GetMinPoint |
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| 156 | // |
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| 157 | // Returns pointer to minimum point along the specified axis. |
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| 158 | // Take care! Do not use pointer after destroying parent polygon. |
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| 159 | // |
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| 160 | const G4ThreeVector *G4ClippablePolygon::GetMinPoint( const EAxis axis ) const |
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| 161 | { |
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| 162 | G4int noLeft = vertices.size(); |
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| 163 | if (noLeft==0) |
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| 164 | G4Exception("G4ClippablePolygon::GetMinPoint()", |
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| 165 | "InvalidSetup", FatalException, "Empty polygon."); |
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| 166 | |
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| 167 | const G4ThreeVector *answer = &(vertices[0]); |
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| 168 | G4double min = answer->operator()(axis); |
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| 169 | |
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| 170 | G4int i; |
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| 171 | for( i=1; i<noLeft; i++ ) |
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| 172 | { |
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| 173 | G4double component = vertices[i].operator()( axis ); |
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| 174 | if (component < min) |
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| 175 | { |
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| 176 | answer = &(vertices[i]); |
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| 177 | min = component; |
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| 178 | } |
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| 179 | } |
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| 180 | |
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| 181 | return answer; |
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| 182 | } |
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| 183 | |
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| 184 | |
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| 185 | // |
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| 186 | // GetMaxPoint |
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| 187 | // |
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| 188 | // Returns pointer to maximum point along the specified axis. |
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| 189 | // Take care! Do not use pointer after destroying parent polygon. |
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| 190 | // |
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| 191 | const G4ThreeVector *G4ClippablePolygon::GetMaxPoint( const EAxis axis ) const |
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| 192 | { |
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| 193 | G4int noLeft = vertices.size(); |
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| 194 | if (noLeft==0) |
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| 195 | G4Exception("G4ClippablePolygon::GetMaxPoint()", |
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| 196 | "InvalidSetup", FatalException, "Empty polygon."); |
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| 197 | |
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| 198 | const G4ThreeVector *answer = &(vertices[0]); |
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| 199 | G4double max = answer->operator()(axis); |
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| 200 | |
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| 201 | G4int i; |
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| 202 | for( i=1; i<noLeft; i++ ) |
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| 203 | { |
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| 204 | G4double component = vertices[i].operator()( axis ); |
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| 205 | if (component > max) |
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| 206 | { |
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| 207 | answer = &(vertices[i]); |
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| 208 | max = component; |
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| 209 | } |
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| 210 | } |
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| 211 | |
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| 212 | return answer; |
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| 213 | } |
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| 214 | |
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| 215 | |
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| 216 | // |
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| 217 | // InFrontOf |
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| 218 | // |
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| 219 | // Decide if this polygon is in "front" of another when |
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| 220 | // viewed along the specified axis. For our purposes here, |
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| 221 | // it is sufficient to use the minimum extent of the |
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| 222 | // polygon along the axis to determine this. |
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| 223 | // |
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| 224 | // In case the minima of the two polygons are equal, |
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| 225 | // we use a more sophisticated test. |
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| 226 | // |
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| 227 | // Note that it is possible for the two following |
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| 228 | // statements to both return true or both return false: |
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| 229 | // polygon1.InFrontOf(polygon2) |
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| 230 | // polygon2.BehindOf(polygon1) |
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| 231 | // |
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| 232 | G4bool G4ClippablePolygon::InFrontOf( const G4ClippablePolygon &other, |
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| 233 | EAxis axis ) const |
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| 234 | { |
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| 235 | // |
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| 236 | // If things are empty, do something semi-sensible |
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| 237 | // |
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| 238 | G4int noLeft = vertices.size(); |
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| 239 | if (noLeft==0) return false; |
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| 240 | |
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| 241 | if (other.Empty()) return true; |
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| 242 | |
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| 243 | // |
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| 244 | // Get minimum of other polygon |
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| 245 | // |
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| 246 | const G4ThreeVector *minPointOther = other.GetMinPoint( axis ); |
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| 247 | const G4double minOther = minPointOther->operator()(axis); |
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| 248 | |
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| 249 | // |
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| 250 | // Get minimum of this polygon |
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| 251 | // |
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| 252 | const G4ThreeVector *minPoint = GetMinPoint( axis ); |
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| 253 | const G4double min = minPoint->operator()(axis); |
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| 254 | |
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| 255 | // |
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| 256 | // Easy decision |
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| 257 | // |
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| 258 | if (min < minOther-kCarTolerance) return true; // Clear winner |
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| 259 | |
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| 260 | if (minOther < min-kCarTolerance) return false; // Clear loser |
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| 261 | |
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| 262 | // |
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| 263 | // We have a tie (this will not be all that rare since our |
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| 264 | // polygons are connected) |
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| 265 | // |
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| 266 | // Check to see if there is a vertex in the other polygon |
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| 267 | // that is behind this one (or vice versa) |
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| 268 | // |
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| 269 | G4bool answer; |
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| 270 | G4ThreeVector normalOther = other.GetNormal(); |
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| 271 | |
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| 272 | if (std::fabs(normalOther(axis)) > std::fabs(normal(axis))) |
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| 273 | { |
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| 274 | G4double minP, maxP; |
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| 275 | GetPlanerExtent( *minPointOther, normalOther, minP, maxP ); |
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| 276 | |
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| 277 | answer = (normalOther(axis) > 0) ? (minP < -kCarTolerance) |
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| 278 | : (maxP > +kCarTolerance); |
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| 279 | } |
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| 280 | else |
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| 281 | { |
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| 282 | G4double minP, maxP; |
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| 283 | other.GetPlanerExtent( *minPoint, normal, minP, maxP ); |
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| 284 | |
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| 285 | answer = (normal(axis) > 0) ? (maxP > +kCarTolerance) |
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| 286 | : (minP < -kCarTolerance); |
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| 287 | } |
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| 288 | return answer; |
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| 289 | } |
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| 290 | |
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| 291 | // |
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| 292 | // BehindOf |
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| 293 | // |
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| 294 | // Decide if this polygon is behind another. |
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| 295 | // See notes in method "InFrontOf" |
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| 296 | // |
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| 297 | G4bool G4ClippablePolygon::BehindOf( const G4ClippablePolygon &other, |
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| 298 | EAxis axis ) const |
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| 299 | { |
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| 300 | // |
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| 301 | // If things are empty, do something semi-sensible |
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| 302 | // |
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| 303 | G4int noLeft = vertices.size(); |
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| 304 | if (noLeft==0) return false; |
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| 305 | |
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| 306 | if (other.Empty()) return true; |
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| 307 | |
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| 308 | // |
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| 309 | // Get minimum of other polygon |
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| 310 | // |
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| 311 | const G4ThreeVector *maxPointOther = other.GetMaxPoint( axis ); |
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| 312 | const G4double maxOther = maxPointOther->operator()(axis); |
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| 313 | |
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| 314 | // |
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| 315 | // Get minimum of this polygon |
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| 316 | // |
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| 317 | const G4ThreeVector *maxPoint = GetMaxPoint( axis ); |
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| 318 | const G4double max = maxPoint->operator()(axis); |
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| 319 | |
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| 320 | // |
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| 321 | // Easy decision |
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| 322 | // |
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| 323 | if (max > maxOther+kCarTolerance) return true; // Clear winner |
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| 324 | |
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| 325 | if (maxOther > max+kCarTolerance) return false; // Clear loser |
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| 326 | |
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| 327 | // |
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| 328 | // We have a tie (this will not be all that rare since our |
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| 329 | // polygons are connected) |
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| 330 | // |
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| 331 | // Check to see if there is a vertex in the other polygon |
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| 332 | // that is in front of this one (or vice versa) |
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| 333 | // |
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| 334 | G4bool answer; |
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| 335 | G4ThreeVector normalOther = other.GetNormal(); |
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| 336 | |
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| 337 | if (std::fabs(normalOther(axis)) > std::fabs(normal(axis))) |
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| 338 | { |
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| 339 | G4double minP, maxP; |
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| 340 | GetPlanerExtent( *maxPointOther, normalOther, minP, maxP ); |
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| 341 | |
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| 342 | answer = (normalOther(axis) > 0) ? (maxP > +kCarTolerance) |
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| 343 | : (minP < -kCarTolerance); |
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| 344 | } |
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| 345 | else |
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| 346 | { |
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| 347 | G4double minP, maxP; |
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| 348 | other.GetPlanerExtent( *maxPoint, normal, minP, maxP ); |
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| 349 | |
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| 350 | answer = (normal(axis) > 0) ? (minP < -kCarTolerance) |
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| 351 | : (maxP > +kCarTolerance); |
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| 352 | } |
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| 353 | return answer; |
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| 354 | } |
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| 355 | |
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| 356 | |
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| 357 | // |
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| 358 | // GetPlanerExtent |
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| 359 | // |
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| 360 | // Get min/max distance in or out of a plane |
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| 361 | // |
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| 362 | G4bool G4ClippablePolygon::GetPlanerExtent( const G4ThreeVector &pointOnPlane, |
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| 363 | const G4ThreeVector &planeNormal, |
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| 364 | G4double &min, |
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| 365 | G4double &max ) const |
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| 366 | { |
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| 367 | // |
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| 368 | // Okay, how many entries do we have? |
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| 369 | // |
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| 370 | G4int noLeft = vertices.size(); |
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| 371 | |
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| 372 | // |
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| 373 | // Return false if nothing is left |
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| 374 | // |
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| 375 | if (noLeft == 0) return false; |
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| 376 | |
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| 377 | // |
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| 378 | // Initialize min and max to our first vertex |
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| 379 | // |
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| 380 | min = max = planeNormal.dot(vertices[0]-pointOnPlane); |
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| 381 | |
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| 382 | // |
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| 383 | // Compare to the rest |
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| 384 | // |
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| 385 | G4int i; |
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| 386 | for( i=1; i<noLeft; i++ ) |
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| 387 | { |
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| 388 | G4double component = planeNormal.dot(vertices[i] - pointOnPlane); |
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| 389 | if (component < min ) |
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| 390 | min = component; |
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| 391 | else if (component > max ) |
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| 392 | max = component; |
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| 393 | } |
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| 394 | |
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| 395 | return true; |
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| 396 | } |
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| 397 | |
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| 398 | |
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| 399 | // |
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| 400 | // Clip along just one axis, as specified in voxelLimit |
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| 401 | // |
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| 402 | void G4ClippablePolygon::ClipAlongOneAxis( const G4VoxelLimits &voxelLimit, |
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| 403 | const EAxis axis ) |
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| 404 | { |
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| 405 | if (!voxelLimit.IsLimited(axis)) return; |
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| 406 | |
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| 407 | G4ThreeVectorList tempPolygon; |
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| 408 | |
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| 409 | // |
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| 410 | // Build a "simple" voxelLimit that includes only the min extent |
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| 411 | // and apply this to our vertices, producing result in tempPolygon |
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| 412 | // |
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| 413 | G4VoxelLimits simpleLimit1; |
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| 414 | simpleLimit1.AddLimit( axis, voxelLimit.GetMinExtent(axis), kInfinity ); |
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| 415 | ClipToSimpleLimits( vertices, tempPolygon, simpleLimit1 ); |
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| 416 | |
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| 417 | // |
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| 418 | // If nothing is left from the above clip, we might as well return now |
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| 419 | // (but with an empty vertices) |
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| 420 | // |
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| 421 | if (tempPolygon.size() == 0) |
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| 422 | { |
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| 423 | vertices.clear(); |
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| 424 | return; |
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| 425 | } |
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| 426 | |
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| 427 | // |
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| 428 | // Now do the same, but using a "simple" limit that includes only the max |
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| 429 | // extent. Apply this to out tempPolygon, producing result in vertices. |
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| 430 | // |
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| 431 | G4VoxelLimits simpleLimit2; |
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| 432 | simpleLimit2.AddLimit( axis, -kInfinity, voxelLimit.GetMaxExtent(axis) ); |
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| 433 | ClipToSimpleLimits( tempPolygon, vertices, simpleLimit2 ); |
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| 434 | |
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| 435 | // |
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| 436 | // If nothing is left, return now |
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| 437 | // |
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| 438 | if (vertices.size() == 0) return; |
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| 439 | } |
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| 440 | |
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| 441 | |
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| 442 | // |
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| 443 | // pVoxelLimits must be only limited along one axis, and either the maximum |
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| 444 | // along the axis must be +kInfinity, or the minimum -kInfinity |
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| 445 | // |
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| 446 | void G4ClippablePolygon::ClipToSimpleLimits( G4ThreeVectorList& pPolygon, |
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| 447 | G4ThreeVectorList& outputPolygon, |
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| 448 | const G4VoxelLimits& pVoxelLimit ) |
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| 449 | { |
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| 450 | G4int i; |
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| 451 | G4int noVertices=pPolygon.size(); |
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| 452 | G4ThreeVector vEnd,vStart; |
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| 453 | |
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| 454 | outputPolygon.clear(); |
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| 455 | |
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| 456 | for (i=0;i<noVertices;i++) |
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| 457 | { |
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| 458 | vStart=pPolygon[i]; |
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| 459 | if (i==noVertices-1) |
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| 460 | { |
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| 461 | vEnd=pPolygon[0]; |
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| 462 | } |
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| 463 | else |
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| 464 | { |
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| 465 | vEnd=pPolygon[i+1]; |
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| 466 | } |
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| 467 | |
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| 468 | if (pVoxelLimit.Inside(vStart)) |
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| 469 | { |
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| 470 | if (pVoxelLimit.Inside(vEnd)) |
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| 471 | { |
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| 472 | // vStart and vEnd inside -> output end point |
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| 473 | // |
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| 474 | outputPolygon.push_back(vEnd); |
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| 475 | } |
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| 476 | else |
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| 477 | { |
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| 478 | // vStart inside, vEnd outside -> output crossing point |
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| 479 | // |
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| 480 | pVoxelLimit.ClipToLimits(vStart,vEnd); |
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| 481 | outputPolygon.push_back(vEnd); |
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| 482 | } |
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| 483 | } |
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| 484 | else |
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| 485 | { |
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| 486 | if (pVoxelLimit.Inside(vEnd)) |
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| 487 | { |
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| 488 | // vStart outside, vEnd inside -> output inside section |
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| 489 | // |
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| 490 | pVoxelLimit.ClipToLimits(vStart,vEnd); |
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| 491 | outputPolygon.push_back(vStart); |
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| 492 | outputPolygon.push_back(vEnd); |
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| 493 | } |
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| 494 | else // Both point outside -> no output |
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| 495 | { |
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| 496 | } |
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| 497 | } |
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| 498 | } |
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| 499 | } |
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