CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Hello,

Thanks for the bug report.

Try replacing the file
include/CGAL/internal/Intersections_3/Bbox_3_Line_3_do_intersect.h
by the one attached.

Please tell us if you encounter another issue.

Best regards,

Sebastien.


DimanNe wrote:
> http://cgal-discuss.949826.n4.nabble.com/file/n3655807/main.cpp main.cpp 
>
> In main.cpp I try to ask is there intersection of
>       TBBox BBox(0, -4, 0,
>                  300, 4, 300);
> and
>       TLine Line(TPoint(150, -5, 0),
>                  TPoint(150, -5, 1));
>
> as you can see y-coord of Line is lower (= -5) than bottom of BBox (= -4)
> but output is
>
> %g++ main.cpp -I/usr/local/include/ -L /usr/local/lib/ -lCGAL
> %./a.out
> 1
> v
> 1
>
>
> %uname -a
> FreeBSD Impedance 9.0-CURRENT FreeBSD 9.0-CURRENT #0: Tue Apr  5 18:35:50
> MSD 2011     
> Void@Impedance:/usr/obj/usr/src/sys/GENERIC
>   i386
>
> %g++ --version
> g++ (GCC) 4.2.2 20070831 prerelease [FreeBSD]
> Copyright (C) 2007 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.  There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
>
>
>
> PORTNAME=       cgal
> PORTVERSION=    3.6.1
>
>
> --
> View this message in context: 
> http://cgal-discuss.949826.n4.nabble.com/do-intersect-bug-tp3655807p3655807.html
> Sent from the cgal-discuss mailing list archive at Nabble.com.

// Copyright (c) 2008 ETH Zurich (Switzerland)
// Copyright (c) 2008-2009 INRIA Sophia-Antipolis (France)
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; version 2.1 of the License.
// See the file LICENSE.LGPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/trunk/Intersections_3/include/CGAL/internal/Intersections_3/Bbox_3_Line_3_do_intersect.h $
// $Id: Bbox_3_Line_3_do_intersect.h 56667 2010-06-09 07:37:13Z sloriot $
//
//
// Author(s)     : Camille Wormser, Jane Tournois, Pierre Alliez, Stephane Tayeb


#ifndef CGAL_INTERNAL_INTERSECTIONS_3_BBOX_3_LINE_3_DO_INTERSECT_H
#define CGAL_INTERNAL_INTERSECTIONS_3_BBOX_3_LINE_3_DO_INTERSECT_H

#include <CGAL/Line_3.h>
#include <CGAL/Bbox_3.h>

// inspired from http://cag.csail.mit.edu/~amy/papers/box-jgt.pdf

namespace CGAL {

namespace internal {

  template <typename FT>
  inline
  bool
  bbox_line_do_intersect_aux(const FT& px, const FT& py, const FT& pz,
                             const FT& qx, const FT& qy, const FT& qz,
                             const FT& bxmin, const FT& bymin, const FT& bzmin,
                             const FT& bxmax, const FT& bymax, const FT& bzmax)
  {
    // -----------------------------------
    // treat x coord
    // -----------------------------------
    FT dmin, tmin, tmax;
    if ( qx >= px )
    {
      tmin = bxmin - px;
      tmax = bxmax - px;
      dmin = qx - px;
    }
    else
    {
      tmin = px - bxmax;
      tmax = px - bxmin;
      dmin = px - qx;
    }

    //if px is not in the x-slab
    if ( dmin == FT(0) && (tmin > FT(0) || tmax < FT(0)) ) return false;

    FT dmax = dmin;

    // -----------------------------------
    // treat y coord
    // -----------------------------------
    FT d_, tmin_, tmax_;
    if ( qy >= py )
    {
      tmin_ = bymin - py;
      tmax_ = bymax - py;
      d_ = qy - py;
    }
    else
    {
      tmin_ = py - bymax;
      tmax_ = py - bymin;
      d_ = py - qy;
    }
    
    //if py is not in the y-slab
    if ( d_ == FT(0) && (tmin_ > FT(0) || tmax_ < FT(0)) ) return false;

    if ( (dmin*tmax_) < (d_*tmin) || (dmax*tmin_) > (d_*tmax) )
      return false;

    if( (dmin*tmin_) > (d_*tmin) )
    {
      tmin = tmin_;
      dmin = d_;
    }

    if( (dmax*tmax_) < (d_*tmax) )
    {
      tmax = tmax_;
      dmax = d_;
    }

    // -----------------------------------
    // treat z coord
    // -----------------------------------
    if ( qz >= pz )
    {
      tmin_ = bzmin - pz;
      tmax_ = bzmax - pz;
      d_ = qz - pz;
    }
    else
    {
      tmin_ = pz - bzmax;
      tmax_ = pz - bzmin;
      d_ = pz - qz;
    }
    
    //if pz is not in the z-slab
    if ( d_ == FT(0) && (tmin_ > FT(0) || tmax_ < FT(0)) ) return false;

    return ( (dmin*tmax_) >= (d_*tmin) && (dmax*tmin_) <= (d_*tmax) );
  }

  template <class K>
  bool do_intersect(const typename K::Line_3& line,
                    const CGAL::Bbox_3& bbox,
                    const K&)
  {
    typedef typename K::FT FT;
    typedef typename K::Point_3 Point_3;
    typedef typename K::Vector_3 Vector_3;

    const Point_3& point = line.point();
    const Vector_3& v = line.to_vector();

    return bbox_line_do_intersect_aux(
                         point.x(), point.y(), point.z(),
                         point.x()+v.x(), point.y()+v.y(), point.z()+v.z(),
                         FT(bbox.xmin()), FT(bbox.ymin()), FT(bbox.zmin()),
                         FT(bbox.xmax()), FT(bbox.ymax()), FT(bbox.zmax()) );
  }

} // namespace internal

template <class K>
bool do_intersect(const CGAL::Line_3<K>& line,
		  const CGAL::Bbox_3& bbox)
{
  return typename K::Do_intersect_3()(line, bbox);
}

template <class K>
bool do_intersect(const CGAL::Bbox_3& bbox,
		  const CGAL::Line_3<K>& line)
{
  return typename K::Do_intersect_3()(line, bbox);
}

} //namespace CGAL

#endif  // CGAL_INTERNAL_INTERSECTIONS_3_BBOX_3_LINE_3_DO_INTERSECT_H