[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: G4LineSection.cc,v 1.10 2006/06/29 18:24:16 gunter Exp $ |
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[1337] | 28 | // GEANT4 tag $Name: geant4-09-04-beta-01 $ |
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[831] | 29 | // |
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| 30 | // -------------------------------------------------------------------- |
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| 31 | |
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| 32 | #include "G4LineSection.hh" |
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| 33 | |
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| 34 | G4LineSection::G4LineSection( const G4ThreeVector& PntA, |
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| 35 | const G4ThreeVector& PntB ) |
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| 36 | : EndpointA(PntA), |
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| 37 | VecAtoB(PntB-PntA) |
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| 38 | { |
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| 39 | fABdistanceSq = VecAtoB.mag2() ; |
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| 40 | /* |
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| 41 | G4double distABsquared = VecAtoB.mag2() ; |
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| 42 | if ( distABsquared == 0.0) |
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| 43 | { |
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| 44 | G4Exception("G4LineSection::G4LineSection()", "WrongArgumentValue", |
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| 45 | FatalException, "Equal points in input (line->point) ?") ; |
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| 46 | } |
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| 47 | else |
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| 48 | { |
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| 49 | inverse_square_distAB=1.0 / distABsquared ; |
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| 50 | } |
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| 51 | */ |
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| 52 | } |
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| 53 | |
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| 54 | G4double G4LineSection::Dist( G4ThreeVector OtherPnt ) const |
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| 55 | { |
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| 56 | G4double dist_sq; |
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| 57 | G4ThreeVector VecAZ; |
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| 58 | G4double sq_VecAZ, inner_prod, unit_projection ; |
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| 59 | |
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| 60 | VecAZ= OtherPnt - EndpointA; |
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| 61 | sq_VecAZ = VecAZ.mag2(); |
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| 62 | |
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| 63 | inner_prod= VecAtoB.dot( VecAZ ); |
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| 64 | |
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| 65 | // Determine Projection(AZ on AB) / Length(AB) |
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| 66 | // |
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| 67 | if( fABdistanceSq != 0.0 ) |
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| 68 | { |
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| 69 | // unit_projection= inner_prod * InvsqDistAB(); |
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| 70 | unit_projection = inner_prod/fABdistanceSq; |
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| 71 | |
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| 72 | if( (0. <= unit_projection ) && (unit_projection <= 1.0 ) ) |
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| 73 | { |
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| 74 | dist_sq= sq_VecAZ - unit_projection * inner_prod ; |
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| 75 | } |
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| 76 | else |
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| 77 | { |
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| 78 | // The perpendicular from the point to the line AB meets the line |
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| 79 | // in a point outside the line segment! |
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| 80 | |
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| 81 | if( unit_projection < 0. ) // A is the closest point |
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| 82 | { |
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| 83 | dist_sq= sq_VecAZ; |
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| 84 | } |
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| 85 | else // B is the closest point |
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| 86 | { |
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| 87 | G4ThreeVector EndpointB = EndpointA + VecAtoB; |
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| 88 | G4ThreeVector VecBZ = OtherPnt - EndpointB; |
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| 89 | dist_sq = VecBZ.mag2(); |
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| 90 | } |
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| 91 | } |
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| 92 | } |
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| 93 | else |
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| 94 | { |
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| 95 | dist_sq = (OtherPnt - EndpointA).mag2() ; |
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| 96 | } |
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| 97 | if( dist_sq < 0.0 ) dist_sq = 0.0 ; |
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| 98 | |
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| 99 | return std::sqrt(dist_sq) ; |
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| 100 | } |
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| 101 | |
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| 102 | G4double G4LineSection::Distline( const G4ThreeVector& OtherPnt, |
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| 103 | const G4ThreeVector& LinePntA, |
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| 104 | const G4ThreeVector& LinePntB ) |
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| 105 | { |
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| 106 | G4LineSection LineAB( LinePntA, LinePntB ); // Line from A to B |
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| 107 | |
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| 108 | return LineAB.Dist( OtherPnt ); |
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| 109 | } |
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