tools/source/generic/line.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <tools/line.hxx>
  21 #include <tools/helpers.hxx>
  22
  23 #include <cmath>
  24
  25 namespace tools
  26 {
  27
  28 double Line::GetLength() const
  29 {
  30     return hypot( maStart.X() - maEnd.X(), maStart.Y() - maEnd.Y() );
  31 }
  32
  33 bool Line::Intersection( const Line& rLine, Point& rIntersection ) const
  34 {
  35     double  fX, fY;
  36     bool    bRet;
  37
  38     if( Intersection( rLine, fX, fY ) )
  39     {
  40         rIntersection.setX( FRound( fX ) );
  41         rIntersection.setY( FRound( fY ) );
  42         bRet = true;
  43     }
  44     else
  45         bRet = false;
  46
  47     return bRet;
  48 }
  49
  50 bool Line::Intersection( const tools::Line& rLine, double& rIntersectionX, double& rIntersectionY ) const
  51 {
  52     const double    fAx = maEnd.X() - maStart.X();
  53     const double    fAy = maEnd.Y() - maStart.Y();
  54     const double    fBx = rLine.maStart.X() - rLine.maEnd.X();
  55     const double    fBy = rLine.maStart.Y() - rLine.maEnd.Y();
  56     const double    fDen = fAy * fBx - fAx * fBy;
  57     bool            bOk = false;
  58
  59     if( fDen != 0. )
  60     {
  61         const double    fCx = maStart.X() - rLine.maStart.X();
  62         const double    fCy = maStart.Y() - rLine.maStart.Y();
  63         const double    fA = fBy * fCx - fBx * fCy;
  64         const bool      bGreater = ( fDen > 0. );
  65
  66         bOk = true;
  67
  68         if ( bGreater )
  69         {
  70             if ( ( fA < 0. ) || ( fA > fDen ) )
  71                 bOk = false;
  72         }
  73         else if ( ( fA > 0. ) || ( fA < fDen ) )
  74             bOk = false;
  75
  76         if ( bOk )
  77         {
  78             const double fB = fAx * fCy - fAy * fCx;
  79
  80             if ( bGreater )
  81             {
  82                 if ( ( fB < 0. ) || ( fB > fDen ) )
  83                     bOk = false;
  84             }
  85             else if ( ( fB > 0. ) || ( fB < fDen ) )
  86                 bOk = false;
  87
  88             if( bOk )
  89             {
  90                 const double fAlpha = fA / fDen;
  91
  92                 rIntersectionX = ( maStart.X() + fAlpha * fAx );
  93                 rIntersectionY = ( maStart.Y() + fAlpha * fAy );
  94             }
  95         }
  96     }
  97
  98     return bOk;
  99 }
 100
 101 double Line::GetDistance( const double& rPtX, const double& rPtY ) const
 102 {
 103     double fDist;
 104
 105     if( maStart != maEnd )
 106     {
 107         const double    fDistX = maEnd.X() - maStart.X();
 108         const double    fDistY = maEnd.Y() - maStart.Y();
 109         const double    fACX = maStart.X() - rPtX;
 110         const double    fACY = maStart.Y() - rPtY;
 111         const double    fL2 = fDistX * fDistX + fDistY * fDistY;
 112         const double    fR = ( fACY * -fDistY - fACX * fDistX ) / fL2;
 113         const double    fS = ( fACY * fDistX - fACX * fDistY ) / fL2;
 114
 115         if( fR < 0.0 )
 116         {
 117             fDist = hypot( maStart.X() - rPtX, maStart.Y() - rPtY );
 118
 119             if( fS < 0.0 )
 120                 fDist *= -1.0;
 121         }
 122         else if( fR <= 1.0 )
 123             fDist = fS * sqrt( fL2 );
 124         else
 125         {
 126             fDist = hypot( maEnd.X() - rPtX, maEnd.Y() - rPtY );
 127
 128             if( fS < 0.0 )
 129                 fDist *= -1.0;
 130         }
 131     }
 132     else
 133         fDist = hypot( maStart.X() - rPtX, maStart.Y() - rPtY );
 134
 135     return fDist;
 136 }
 137
 138 } //namespace tools
 139
 140 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */