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/link.hxx>
  21 #include <tools/line.hxx>
  22 #include <tools/helpers.hxx>
  23
  24 #include <cstdlib>
  25 #include <math.h>
  26
  27 double Line::GetLength() const
  28 {
  29     return hypot( maStart.X() - maEnd.X(), maStart.Y() - maEnd.Y() );
  30 }
  31
  32 bool Line::Intersection( const Line& rLine, Point& rIntersection ) const
  33 {
  34     double  fX, fY;
  35     bool    bRet;
  36
  37     if( Intersection( rLine, fX, fY ) )
  38     {
  39         rIntersection.X() = FRound( fX );
  40         rIntersection.Y() = FRound( fY );
  41         bRet = true;
  42     }
  43     else
  44         bRet = false;
  45
  46     return bRet;
  47 }
  48
  49 bool Line::Intersection( const Line& rLine, double& rIntersectionX, double& rIntersectionY ) const
  50 {
  51     const double    fAx = maEnd.X() - maStart.X();
  52     const double    fAy = maEnd.Y() - maStart.Y();
  53     const double    fBx = rLine.maStart.X() - rLine.maEnd.X();
  54     const double    fBy = rLine.maStart.Y() - rLine.maEnd.Y();
  55     const double    fDen = fAy * fBx - fAx * fBy;
  56     bool            bOk = false;
  57
  58     if( fDen != 0. )
  59     {
  60         const double    fCx = maStart.X() - rLine.maStart.X();
  61         const double    fCy = maStart.Y() - rLine.maStart.Y();
  62         const double    fA = fBy * fCx - fBx * fCy;
  63         const bool      bGreater = ( fDen > 0. );
  64
  65         bOk = true;
  66
  67         if ( bGreater )
  68         {
  69             if ( ( fA < 0. ) || ( fA > fDen ) )
  70                 bOk = false;
  71         }
  72         else if ( ( fA > 0. ) || ( fA < fDen ) )
  73             bOk = false;
  74
  75         if ( bOk )
  76         {
  77             const double fB = fAx * fCy - fAy * fCx;
  78
  79             if ( bGreater )
  80             {
  81                 if ( ( fB < 0. ) || ( fB > fDen ) )
  82                     bOk = false;
  83             }
  84             else if ( ( fB > 0. ) || ( fB < fDen ) )
  85                 bOk = false;
  86
  87             if( bOk )
  88             {
  89                 const double fAlpha = fA / fDen;
  90
  91                 rIntersectionX = ( maStart.X() + fAlpha * fAx );
  92                 rIntersectionY = ( maStart.Y() + fAlpha * fAy );
  93             }
  94         }
  95     }
  96
  97     return bOk;
  98 }
  99
 100 double Line::GetDistance( const double& rPtX, const double& rPtY ) const
 101 {
 102     double fDist;
 103
 104     if( maStart != maEnd )
 105     {
 106         const double    fDistX = maEnd.X() - maStart.X();
 107         const double    fDistY = maEnd.Y() - maStart.Y();
 108         const double    fACX = maStart.X() - rPtX;
 109         const double    fACY = maStart.Y() - rPtY;
 110         const double    fL2 = fDistX * fDistX + fDistY * fDistY;
 111         const double    fR = ( fACY * -fDistY - fACX * fDistX ) / fL2;
 112         const double    fS = ( fACY * fDistX - fACX * fDistY ) / fL2;
 113
 114         if( fR < 0.0 )
 115         {
 116             fDist = hypot( maStart.X() - rPtX, maStart.Y() - rPtY );
 117
 118             if( fS < 0.0 )
 119                 fDist *= -1.0;
 120         }
 121         else if( fR <= 1.0 )
 122             fDist = fS * sqrt( fL2 );
 123         else
 124         {
 125             fDist = hypot( maEnd.X() - rPtX, maEnd.Y() - rPtY );
 126
 127             if( fS < 0.0 )
 128                 fDist *= -1.0;
 129         }
 130     }
 131     else
 132         fDist = hypot( maStart.X() - rPtX, maStart.Y() - rPtY );
 133
 134     return fDist;
 135 }
 136
 137 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */