OpenSceneGraph/src/osg/LineSegment.cpp
2012-03-21 17:36:20 +00:00

461 lines
10 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#include <osg/LineSegment>
using namespace osg;
LineSegment::~LineSegment()
{
}
bool LineSegment::intersectAndClip(vec_type& s,vec_type& e,const BoundingBox& bb)
{
// compate s and e against the xMin to xMax range of bb.
if (s.x()<=e.x())
{
// trivial reject of segment wholely outside.
if (e.x()<bb.xMin()) return false;
if (s.x()>bb.xMax()) return false;
if (s.x()<bb.xMin())
{
// clip s to xMin.
s = s+(e-s)*(bb.xMin()-s.x())/(e.x()-s.x());
}
if (e.x()>bb.xMax())
{
// clip e to xMax.
e = s+(e-s)*(bb.xMax()-s.x())/(e.x()-s.x());
}
}
else
{
if (s.x()<bb.xMin()) return false;
if (e.x()>bb.xMax()) return false;
if (e.x()<bb.xMin())
{
// clip s to xMin.
e = s+(e-s)*(bb.xMin()-s.x())/(e.x()-s.x());
}
if (s.x()>bb.xMax())
{
// clip e to xMax.
s = s+(e-s)*(bb.xMax()-s.x())/(e.x()-s.x());
}
}
// compate s and e against the yMin to yMax range of bb.
if (s.y()<=e.y())
{
// trivial reject of segment wholely outside.
if (e.y()<bb.yMin()) return false;
if (s.y()>bb.yMax()) return false;
if (s.y()<bb.yMin())
{
// clip s to yMin.
s = s+(e-s)*(bb.yMin()-s.y())/(e.y()-s.y());
}
if (e.y()>bb.yMax())
{
// clip e to yMax.
e = s+(e-s)*(bb.yMax()-s.y())/(e.y()-s.y());
}
}
else
{
if (s.y()<bb.yMin()) return false;
if (e.y()>bb.yMax()) return false;
if (e.y()<bb.yMin())
{
// clip s to yMin.
e = s+(e-s)*(bb.yMin()-s.y())/(e.y()-s.y());
}
if (s.y()>bb.yMax())
{
// clip e to yMax.
s = s+(e-s)*(bb.yMax()-s.y())/(e.y()-s.y());
}
}
// compate s and e against the zMin to zMax range of bb.
if (s.z()<=e.z())
{
// trivial reject of segment wholely outside.
if (e.z()<bb.zMin()) return false;
if (s.z()>bb.zMax()) return false;
if (s.z()<bb.zMin())
{
// clip s to zMin.
s = s+(e-s)*(bb.zMin()-s.z())/(e.z()-s.z());
}
if (e.z()>bb.zMax())
{
// clip e to zMax.
e = s+(e-s)*(bb.zMax()-s.z())/(e.z()-s.z());
}
}
else
{
if (s.z()<bb.zMin()) return false;
if (e.z()>bb.zMax()) return false;
if (e.z()<bb.zMin())
{
// clip s to zMin.
e = s+(e-s)*(bb.zMin()-s.z())/(e.z()-s.z());
}
if (s.z()>bb.zMax())
{
// clip e to zMax.
s = s+(e-s)*(bb.zMax()-s.z())/(e.z()-s.z());
}
}
return true;
}
bool LineSegment::intersect(const BoundingBox& bb) const
{
if (!bb.valid()) return false;
vec_type s=_s,e=_e;
return intersectAndClip(s,e,bb);
}
bool LineSegment::intersect(const BoundingBox& bb,float& r1,float& r2) const
{
if (!bb.valid()) return false;
vec_type s=_s,e=_e;
bool result = intersectAndClip(s,e,bb);
if (result)
{
value_type len = (_e-_s).length();
if (len>0.0f)
{
value_type inv_len = 1.0f/len;
r1 = (float)((s-_s).length()*inv_len);
r2 = (float)((e-_e).length()*inv_len);
}
else
{
r1 = 0.0f;
r2 = 0.0f;
}
}
return result;
}
bool LineSegment::intersect(const BoundingBox& bb,double& r1,double& r2) const
{
if (!bb.valid()) return false;
vec_type s=_s,e=_e;
bool result = intersectAndClip(s,e,bb);
if (result)
{
double len = (_e-_s).length();
if (len>0.0)
{
double inv_len = 1.0/len;
r1 = ((s-_s).length()*inv_len);
r2 = ((e-_e).length()*inv_len);
}
else
{
r1 = 0.0;
r2 = 0.0;
}
}
return result;
}
bool LineSegment::intersect(const BoundingSphere& bs,float& r1,float& r2) const
{
vec_type sm = _s-bs._center;
value_type c = sm.length2()-bs._radius*bs._radius;
vec_type se = _e-_s;
value_type a = se.length2();
// check for zero length segment.
if (a==0.0)
{
// check if start point outside sphere radius
if (c>0.0) return false;
// length segment within radius of bounding sphere but zero length
// so return true, and set the ratio so the start point is the one
// to be used.
r1 = 1.0f;
r2 = 0.0f;
return true;
}
value_type b = sm*se*2.0f;
value_type d = b*b-4.0f*a*c;
if (d<0.0f) return false;
d = (value_type)sqrt(d);
value_type div = 1.0f/(2.0f*a);
r1 = (float)((-b-d)*div);
r2 = (float)((-b+d)*div);
if (r1<=0.0f && r2<=0.0f) return false;
if (r1>=1.0f && r2>=1.0f) return false;
return true;
}
bool LineSegment::intersect(const BoundingSphere& bs,double& r1,double& r2) const
{
vec_type sm = _s-bs._center;
value_type c = sm.length2()-bs._radius*bs._radius;
vec_type se = _e-_s;
value_type a = se.length2();
// check for zero length segment.
if (a==0.0)
{
// check if start point outside sphere radius
if (c>0.0) return false;
// length segment within radius of bounding sphere but zero length
// so return true, and set the ratio so the start point is the one
// to be used.
r1 = 1.0f;
r2 = 0.0f;
return true;
}
value_type b = sm*se*2.0;
value_type d = b*b-4.0f*a*c;
if (d<0.0f) return false;
d = (value_type)sqrt(d);
value_type div = 1.0f/(2.0*a);
r1 = ((-b-d)*div);
r2 = ((-b+d)*div);
if (r1<=0.0 && r2<=0.0) return false;
if (r1>=1.0 && r2>=1.0) return false;
return true;
}
bool LineSegment::intersect(const BoundingSphere& bs) const
{
vec_type sm = _s-bs._center;
value_type c = sm.length2()-bs._radius*bs._radius;
if (c<0.0f) return true;
vec_type se = _e-_s;
value_type a = se.length2();
value_type b = (sm*se)*2.0f;
value_type d = b*b-4.0f*a*c;
if (d<0.0f) return false;
d = (value_type) sqrt(d);
value_type div = 1.0f/(2.0f*a);
value_type r1 = (-b-d)*div;
value_type r2 = (-b+d)*div;
if (r1<=0.0f && r2<=0.0f) return false;
if (r1>=1.0f && r2>=1.0f) return false;
return true;
}
bool LineSegment::intersect(const Vec3f& v1,const Vec3f& v2,const Vec3f& v3,float& r)
{
if (v1==v2 || v2==v3 || v1==v3) return false;
vec_type vse = _e-_s;
vec_type v12 = v2-v1;
vec_type n12 = v12^vse;
value_type ds12 = (_s-v1)*n12;
value_type d312 = (v3-v1)*n12;
if (d312>=0.0)
{
if (ds12<0.0) return false;
if (ds12>d312) return false;
}
else // d312 < 0
{
if (ds12>0.0) return false;
if (ds12<d312) return false;
}
vec_type v23 = v3-v2;
vec_type n23 = v23^vse;
value_type ds23 = (_s-v2)*n23;
value_type d123 = (v1-v2)*n23;
if (d123>=0.0)
{
if (ds23<0.0) return false;
if (ds23>d123) return false;
}
else // d123 < 0
{
if (ds23>0.0) return false;
if (ds23<d123) return false;
}
vec_type v31 = v1-v3;
vec_type n31 = v31^vse;
value_type ds31 = (_s-v3)*n31;
value_type d231 = (v2-v3)*n31;
if (d231>=0.0)
{
if (ds31<0.0) return false;
if (ds31>d231) return false;
}
else // d231 < 0
{
if (ds31>0.0) return false;
if (ds31<d231) return false;
}
value_type r3 = ds12/d312;
value_type r1 = ds23/d123;
value_type r2 = ds31/d231;
// value_type rt = r1+r2+r3;
vec_type in = v1*r1+v2*r2+v3*r3;
value_type length = vse.length();
vse /= length;
value_type d = (in-_s)*vse;
if (d<0.0) return false;
if (d>length) return false;
r = (float) d/length;
return true;
}
bool LineSegment::intersect(const Vec3d& v1,const Vec3d& v2,const Vec3d& v3,double& r)
{
if (v1==v2 || v2==v3 || v1==v3) return false;
vec_type vse = _e-_s;
vec_type v12 = v2-v1;
vec_type n12 = v12^vse;
value_type ds12 = (_s-v1)*n12;
value_type d312 = (v3-v1)*n12;
if (d312>=0.0)
{
if (ds12<0.0) return false;
if (ds12>d312) return false;
}
else // d312 < 0
{
if (ds12>0.0) return false;
if (ds12<d312) return false;
}
vec_type v23 = v3-v2;
vec_type n23 = v23^vse;
value_type ds23 = (_s-v2)*n23;
value_type d123 = (v1-v2)*n23;
if (d123>=0.0)
{
if (ds23<0.0) return false;
if (ds23>d123) return false;
}
else // d123 < 0
{
if (ds23>0.0) return false;
if (ds23<d123) return false;
}
vec_type v31 = v1-v3;
vec_type n31 = v31^vse;
value_type ds31 = (_s-v3)*n31;
value_type d231 = (v2-v3)*n31;
if (d231>=0.0)
{
if (ds31<0.0) return false;
if (ds31>d231) return false;
}
else // d231 < 0
{
if (ds31>0.0) return false;
if (ds31<d231) return false;
}
value_type r3 = ds12/d312;
value_type r1 = ds23/d123;
value_type r2 = ds31/d231;
// value_type rt = r1+r2+r3;
vec_type in = v1*r1+v2*r2+v3*r3;
value_type length = vse.length();
vse /= length;
value_type d = (in-_s)*vse;
if (d<0.0) return false;
if (d>length) return false;
r = d/length;
return true;
}