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OpenSceneGraph/src/osgUtil/PlaneIntersector.cpp

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/* -*-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 <osgUtil/PlaneIntersector>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/io_utils>
#include <osg/TriangleFunctor>
using namespace osgUtil;
namespace PlaneIntersectorUtils
{
struct RefPolyline : public osg::Referenced
{
typedef std::vector<osg::Vec4d> Polyline;
Polyline _polyline;
void reverse()
{
unsigned int s=0;
unsigned int e=_polyline.size()-1;
for(; s<e; ++s,--e)
{
std::swap(_polyline[s],_polyline[e]);
}
}
};
class PolylineConnector
{
public:
typedef std::map<osg::Vec4d, osg::ref_ptr<RefPolyline> > PolylineMap;
typedef std::vector< osg::ref_ptr<RefPolyline> > PolylineList;
PolylineList _polylines;
PolylineMap _startPolylineMap;
PolylineMap _endPolylineMap;
osg::ref_ptr<osg::EllipsoidModel> _em;
void add(const osg::Vec3d& v1, const osg::Vec3d& v2)
{
add(osg::Vec4d(v1,0.0), osg::Vec4d(v2,0.0));
}
void add(const osg::Vec4d& v1, const osg::Vec4d& v2)
{
if (v1==v2) return;
PolylineMap::iterator v1_start_itr = _startPolylineMap.find(v1);
PolylineMap::iterator v1_end_itr = _endPolylineMap.find(v1);
PolylineMap::iterator v2_start_itr = _startPolylineMap.find(v2);
PolylineMap::iterator v2_end_itr = _endPolylineMap.find(v2);
unsigned int v1_connections = 0;
if (v1_start_itr != _startPolylineMap.end()) ++v1_connections;
if (v1_end_itr != _endPolylineMap.end()) ++v1_connections;
unsigned int v2_connections = 0;
if (v2_start_itr != _startPolylineMap.end()) ++v2_connections;
if (v2_end_itr != _endPolylineMap.end()) ++v2_connections;
if (v1_connections==0) // v1 is no connected to anything.
{
if (v2_connections==0)
{
// new polyline
newline(v1,v2);
}
else if (v2_connections==1)
{
// v2 must connect to either a start or an end.
if (v2_start_itr != _startPolylineMap.end())
{
insertAtStart(v1, v2_start_itr);
}
else if (v2_end_itr != _endPolylineMap.end())
{
insertAtEnd(v1, v2_end_itr);
}
else
{
osg::notify(osg::NOTICE)<<"Error: should not get here!"<<std::endl;
}
}
else // if (v2_connections==2)
{
// v2 connects to a start and an end - must have a loop in the list!
osg::notify(osg::NOTICE)<<"v2="<<v2<<" must connect to a start and an end - must have a loop!!!!!."<<std::endl;
}
}
else if (v2_connections==0) // v1 is no connected to anything.
{
if (v1_connections==1)
{
// v1 must connect to either a start or an end.
if (v1_start_itr != _startPolylineMap.end())
{
insertAtStart(v2, v1_start_itr);
}
else if (v1_end_itr != _endPolylineMap.end())
{
insertAtEnd(v2, v1_end_itr);
}
else
{
osg::notify(osg::NOTICE)<<"Error: should not get here!"<<std::endl;
}
}
else // if (v1_connections==2)
{
// v1 connects to a start and an end - must have a loop in the list!
osg::notify(osg::NOTICE)<<"v1="<<v1<<" must connect to a start and an end - must have a loop!!!!!."<<std::endl;
}
}
else
{
// v1 and v2 connect to existing lines, now need to fuse them together.
bool v1_connected_to_start = v1_start_itr != _startPolylineMap.end();
bool v1_connected_to_end = v1_end_itr != _endPolylineMap.end();
bool v2_connected_to_start = v2_start_itr != _startPolylineMap.end();
bool v2_connected_to_end = v2_end_itr != _endPolylineMap.end();
if (v1_connected_to_start)
{
if (v2_connected_to_start)
{
fuse_start_to_start(v1_start_itr, v2_start_itr);
}
else if (v2_connected_to_end)
{
fuse_start_to_end(v1_start_itr, v2_end_itr);
}
else
{
osg::notify(osg::NOTICE)<<"Error: should not get here!"<<std::endl;
}
}
else if (v1_connected_to_end)
{
if (v2_connected_to_start)
{
fuse_start_to_end(v2_start_itr, v1_end_itr);
}
else if (v2_connected_to_end)
{
fuse_end_to_end(v1_end_itr, v2_end_itr);
}
else
{
osg::notify(osg::NOTICE)<<"Error: should not get here!"<<std::endl;
}
}
else
{
osg::notify(osg::NOTICE)<<"Error: should not get here!"<<std::endl;
}
}
}
void newline(const osg::Vec4d& v1, const osg::Vec4d& v2)
{
RefPolyline* polyline = new RefPolyline;
polyline->_polyline.push_back(v1);
polyline->_polyline.push_back(v2);
_startPolylineMap[v1] = polyline;
_endPolylineMap[v2] = polyline;
}
void insertAtStart(const osg::Vec4d& v, PolylineMap::iterator v_start_itr)
{
// put v1 at the start of its poyline
RefPolyline* polyline = v_start_itr->second.get();
polyline->_polyline.insert(polyline->_polyline.begin(),v);
// reinsert the polyine at the new v1 end
_startPolylineMap[v] = polyline;
// remove the original entry
_startPolylineMap.erase(v_start_itr);
}
void insertAtEnd(const osg::Vec4d& v, PolylineMap::iterator v_end_itr)
{
// put v1 at the end of its poyline
RefPolyline* polyline = v_end_itr->second.get();
polyline->_polyline.push_back(v);
// reinsert the polyine at the new v1 end
_endPolylineMap[v] = polyline;
// remove the original entry
_endPolylineMap.erase(v_end_itr);
}
void fuse_start_to_start(PolylineMap::iterator start1_itr, PolylineMap::iterator start2_itr)
{
osg::ref_ptr<RefPolyline> poly1 = start1_itr->second;
osg::ref_ptr<RefPolyline> poly2 = start2_itr->second;
PolylineMap::iterator end1_itr = _endPolylineMap.find(poly1->_polyline.back());
PolylineMap::iterator end2_itr = _endPolylineMap.find(poly2->_polyline.back());
// clean up the iterators associated with the original polylines
_startPolylineMap.erase(start1_itr);
_startPolylineMap.erase(start2_itr);
_endPolylineMap.erase(end1_itr);
_endPolylineMap.erase(end2_itr);
// reverse the first polyline
poly1->reverse();
// add the second polyline to the first
poly1->_polyline.insert( poly1->_polyline.end(),
poly2->_polyline.begin(), poly2->_polyline.end() );
_startPolylineMap[poly1->_polyline.front()] = poly1;
_endPolylineMap[poly1->_polyline.back()] = poly1;
}
void fuse_start_to_end(PolylineMap::iterator start_itr, PolylineMap::iterator end_itr)
{
osg::ref_ptr<RefPolyline> end_poly = end_itr->second;
osg::ref_ptr<RefPolyline> start_poly = start_itr->second;
PolylineMap::iterator end_start_poly_itr = _endPolylineMap.find(start_poly->_polyline.back());
// add start_poly to end of end_poly
end_poly->_polyline.insert( end_poly->_polyline.end(),
start_poly->_polyline.begin(), start_poly->_polyline.end() );
// reassign the end of the start poly so that it now points to the merged end_poly
end_start_poly_itr->second = end_poly;
// remove entries for the end of the end_poly and the start of the start_poly
_endPolylineMap.erase(end_itr);
_startPolylineMap.erase(start_itr);
if (end_poly==start_poly)
{
_polylines.push_back(end_poly);
}
}
void fuse_end_to_end(PolylineMap::iterator end1_itr, PolylineMap::iterator end2_itr)
{
// return;
osg::ref_ptr<RefPolyline> poly1 = end1_itr->second;
osg::ref_ptr<RefPolyline> poly2 = end2_itr->second;
PolylineMap::iterator start1_itr = _startPolylineMap.find(poly1->_polyline.front());
PolylineMap::iterator start2_itr = _startPolylineMap.find(poly2->_polyline.front());
// clean up the iterators associated with the original polylines
_startPolylineMap.erase(start1_itr);
_startPolylineMap.erase(start2_itr);
_endPolylineMap.erase(end1_itr);
_endPolylineMap.erase(end2_itr);
// reverse the first polyline
poly2->reverse();
// add the second polyline to the first
poly1->_polyline.insert( poly1->_polyline.end(),
poly2->_polyline.begin(), poly2->_polyline.end() );
_startPolylineMap[poly1->_polyline.front()] = poly1;
_endPolylineMap[poly1->_polyline.back()] = poly1;
}
void consolidatePolylineLists()
{
// move the remaining open ended line segments into the polyline list
for(PolylineMap::iterator sitr = _startPolylineMap.begin();
sitr != _startPolylineMap.end();
++sitr)
{
_polylines.push_back(sitr->second);
}
}
void report()
{
osg::notify(osg::NOTICE)<<"report()"<<std::endl;
osg::notify(osg::NOTICE)<<"start:"<<std::endl;
for(PolylineMap::iterator sitr = _startPolylineMap.begin();
sitr != _startPolylineMap.end();
++sitr)
{
osg::notify(osg::NOTICE)<<" line - start = "<<sitr->first<<" polyline size = "<<sitr->second->_polyline.size()<<std::endl;
}
osg::notify(osg::NOTICE)<<"ends:"<<std::endl;
for(PolylineMap::iterator eitr = _endPolylineMap.begin();
eitr != _endPolylineMap.end();
++eitr)
{
osg::notify(osg::NOTICE)<<" line - end = "<<eitr->first<<" polyline size = "<<eitr->second->_polyline.size()<<std::endl;
}
for(PolylineList::iterator pitr = _polylines.begin();
pitr != _polylines.end();
++pitr)
{
osg::notify(osg::NOTICE)<<"polyline:"<<std::endl;
RefPolyline::Polyline& polyline = (*pitr)->_polyline;
for(RefPolyline::Polyline::iterator vitr = polyline.begin();
vitr != polyline.end();
++vitr)
{
osg::notify(osg::NOTICE)<<" "<<*vitr<<std::endl;
}
}
}
void fuse()
{
osg::notify(osg::NOTICE)<<"supposed to be doing a fuse..."<<std::endl;
}
};
struct TriangleIntersector
{
osg::Plane _plane;
osg::Polytope _polytope;
bool _hit;
osg::ref_ptr<osg::RefMatrix> _matrix;
bool _recordHeightsAsAttributes;
osg::ref_ptr<osg::EllipsoidModel> _em;
PolylineConnector _polylineConnector;
TriangleIntersector()
{
_hit = false;
}
void set(const osg::Plane& plane, const osg::Polytope& polytope, osg::RefMatrix* matrix, bool recordHeightsAsAttributes, osg::EllipsoidModel* em)
{
_plane = plane;
_polytope = polytope;
_hit = false;
_matrix = matrix;
_recordHeightsAsAttributes = recordHeightsAsAttributes;
_em = em;
}
inline double distance(const osg::Plane& plane, const osg::Vec4d& v) const
{
return plane[0]*v.x()+
plane[1]*v.y()+
plane[2]*v.z()+
plane[3];
}
inline void add(osg::Vec4d& vs, osg::Vec4d& ve)
{
if (_polytope.getPlaneList().empty())
{
_polylineConnector.add(vs,ve);
}
else
{
for(osg::Polytope::PlaneList::iterator itr = _polytope.getPlaneList().begin();
itr != _polytope.getPlaneList().end();
++itr)
{
osg::Plane& plane = *itr;
double ds = distance(plane,vs);
double de = distance(plane,ve);
if (ds<0.0)
{
if (de<0.0)
{
// osg::notify(osg::NOTICE)<<"Disgard segment "<<std::endl;
return;
}
// osg::notify(osg::NOTICE)<<"Trim start vs="<<vs;
double div = 1.0/(de-ds);
vs = vs*(de*div) - ve*(ds*div);
// osg::notify(osg::NOTICE)<<" after vs="<<vs<<std::endl;
}
else if (de<0.0)
{
// osg::notify(osg::NOTICE)<<"Trim end ve="<<ve;
double div = 1.0/(ds-de);
ve = ve*(ds*div) - vs*(de*div);
// osg::notify(osg::NOTICE)<<" after ve="<<ve<<std::endl;
}
}
// osg::notify(osg::NOTICE)<<"Segment fine"<<std::endl;
_polylineConnector.add(vs,ve);
}
}
inline void operator () (const osg::Vec3& v1,const osg::Vec3& v2,const osg::Vec3& v3, bool)
{
double d1 = _plane.distance(v1);
double d2 = _plane.distance(v2);
double d3 = _plane.distance(v3);
unsigned int numBelow = 0;
unsigned int numAbove = 0;
unsigned int numOnPlane = 0;
if (d1<0) ++numBelow;
else if (d1>0) ++numAbove;
else ++numOnPlane;
if (d2<0) ++numBelow;
else if (d2>0) ++numAbove;
else ++numOnPlane;
if (d3<0) ++numBelow;
else if (d3>0) ++numAbove;
else ++numOnPlane;
// trivially discard triangles that are completely one side of the plane
if (numAbove==3 || numBelow==3) return;
_hit = true;
if (numOnPlane==3)
{
// triangle lives wholy in the plane
osg::notify(osg::NOTICE)<<"3"<<std::endl;
return;
}
if (numOnPlane==2)
{
// one edge lives wholy in the plane
osg::notify(osg::NOTICE)<<"2"<<std::endl;
return;
}
if (numOnPlane==1)
{
// one point lives wholy in the plane
osg::notify(osg::NOTICE)<<"1"<<std::endl;
return;
}
osg::Vec4d v[2];
unsigned int numIntersects = 0;
osg::Vec4d p1(v1, v1.z());
osg::Vec4d p2(v2, v2.z());
osg::Vec4d p3(v3, v3.z());
if (_em.valid())
{
double latitude, longitude, height;
if (_matrix.valid())
{
osg::Vec3d tp = v1 * (*_matrix);
_em->convertXYZToLatLongHeight(tp.x(), tp.y(), tp.z(), latitude, longitude, height);
p1[3] = height;
tp = v2 * (*_matrix);
_em->convertXYZToLatLongHeight(tp.x(), tp.y(), tp.z(), latitude, longitude, height);
p2[3] = height;
tp = v3 * (*_matrix);
_em->convertXYZToLatLongHeight(tp.x(), tp.y(), tp.z(), latitude, longitude, height);
p3[3] = height;
}
else
{
_em->convertXYZToLatLongHeight(v1.x(), v1.y(), v1.z(), latitude, longitude, height);
p1[3] = height;
_em->convertXYZToLatLongHeight(v2.x(), v2.y(), v2.z(), latitude, longitude, height);
p2[3] = height;
_em->convertXYZToLatLongHeight(v3.x(), v3.y(), v3.z(), latitude, longitude, height);
p3[3] = height;
}
}
if (d1*d2 < 0.0)
{
// edge 12 itersects
double div = 1.0 / (d2-d1);
v[numIntersects++] = p1* (d2*div) - p2 * (d1*div);
}
if (d2*d3 < 0.0)
{
// edge 23 itersects
double div = 1.0 / (d3-d2);
v[numIntersects++] = p2* (d3*div) - p3 * (d2*div);
}
if (d1*d3 < 0.0)
{
if (numIntersects<2)
{
// edge 13 itersects
double div = 1.0 / (d3-d1);
v[numIntersects++] = p1* (d3*div) - p3 * (d1*div);
}
else
{
osg::notify(osg::NOTICE)<<"!!! too many intersecting edges found !!!"<<std::endl;
}
}
add(v[0],v[1]);
}
};
}
///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
//
// PlaneIntersector
//
PlaneIntersector::PlaneIntersector(const osg::Plane& plane, const osg::Polytope& boundingPolytope):
_parent(0),
_recordHeightsAsAttributes(false),
_plane(plane),
_polytope(boundingPolytope)
{
}
PlaneIntersector::PlaneIntersector(CoordinateFrame cf, const osg::Plane& plane, const osg::Polytope& boundingPolytope):
Intersector(cf),
_parent(0),
_recordHeightsAsAttributes(false),
_plane(plane),
_polytope(boundingPolytope)
{
}
Intersector* PlaneIntersector::clone(osgUtil::IntersectionVisitor& iv)
{
if (_coordinateFrame==MODEL && iv.getModelMatrix()==0)
{
osg::ref_ptr<PlaneIntersector> pi = new PlaneIntersector(_plane, _polytope);
pi->_parent = this;
pi->_recordHeightsAsAttributes = _recordHeightsAsAttributes;
pi->_em = _em;
return pi.release();
}
// compute the matrix that takes this Intersector from its CoordinateFrame into the local MODEL coordinate frame
// that geometry in the scene graph will always be in.
osg::Matrix matrix;
switch (_coordinateFrame)
{
case(WINDOW):
if (iv.getWindowMatrix()) matrix.preMult( *iv.getWindowMatrix() );
if (iv.getProjectionMatrix()) matrix.preMult( *iv.getProjectionMatrix() );
if (iv.getViewMatrix()) matrix.preMult( *iv.getViewMatrix() );
if (iv.getModelMatrix()) matrix.preMult( *iv.getModelMatrix() );
break;
case(PROJECTION):
if (iv.getProjectionMatrix()) matrix.preMult( *iv.getProjectionMatrix() );
if (iv.getViewMatrix()) matrix.preMult( *iv.getViewMatrix() );
if (iv.getModelMatrix()) matrix.preMult( *iv.getModelMatrix() );
break;
case(VIEW):
if (iv.getViewMatrix()) matrix.preMult( *iv.getViewMatrix() );
if (iv.getModelMatrix()) matrix.preMult( *iv.getModelMatrix() );
break;
case(MODEL):
if (iv.getModelMatrix()) matrix = *iv.getModelMatrix();
break;
}
osg::Plane plane = _plane;
plane.transformProvidingInverse(matrix);
osg::Polytope transformedPolytope;
transformedPolytope.setAndTransformProvidingInverse(_polytope, matrix);
osg::ref_ptr<PlaneIntersector> pi = new PlaneIntersector(plane, transformedPolytope);
pi->_parent = this;
pi->_recordHeightsAsAttributes = _recordHeightsAsAttributes;
pi->_em = _em;
return pi.release();
}
bool PlaneIntersector::enter(const osg::Node& node)
{
return !node.isCullingActive() ||
( _plane.intersect(node.getBound())==0 && _polytope.contains(node.getBound()) );
}
void PlaneIntersector::leave()
{
// do nothing.
}
void PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)
{
// osg::notify(osg::NOTICE)<<"PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)"<<std::endl;
if ( _plane.intersect( drawable->getBound() )!=0 ) return;
if ( !_polytope.contains( drawable->getBound() ) ) return;
// osg::notify(osg::NOTICE)<<"Succed PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)"<<std::endl;
osg::TriangleFunctor<PlaneIntersectorUtils::TriangleIntersector> ti;
ti.set(_plane, _polytope, iv.getModelMatrix(), _recordHeightsAsAttributes, _em.get());
drawable->accept(ti);
ti._polylineConnector.consolidatePolylineLists();
if (ti._hit)
{
Intersections& intersections = getIntersections();
for(PlaneIntersectorUtils::PolylineConnector::PolylineList::iterator pitr = ti._polylineConnector._polylines.begin();
pitr != ti._polylineConnector._polylines.end();
++pitr)
{
unsigned int pos = intersections.size();
intersections.push_back(Intersection());
Intersection& new_intersection = intersections[pos];
new_intersection.matrix = iv.getModelMatrix();
new_intersection.polyline.reserve((*pitr)->_polyline.size());
if (_recordHeightsAsAttributes) new_intersection.attributes.reserve((*pitr)->_polyline.size());
for(PlaneIntersectorUtils::RefPolyline::Polyline::iterator vitr = (*pitr)->_polyline.begin();
vitr != (*pitr)->_polyline.end();
++vitr)
{
const osg::Vec4d& v = *vitr;
new_intersection.polyline.push_back( osg::Vec3d(v.x(), v.y(), v.z()) );
if (_recordHeightsAsAttributes) new_intersection.attributes.push_back( v.w() );
}
new_intersection.nodePath = iv.getNodePath();
new_intersection.drawable = drawable;
}
}
}
void PlaneIntersector::reset()
{
Intersector::reset();
_intersections.clear();
}