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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/DelaunayTriangulator>
// NB this algorithm makes heavy use of the osgUtil::Tessellator for constrained triangulation.
// truly it is built on the shoulders of giants.
#include <osg/GL>
#include <osg/Vec3>
#include <osg/Array>
#include <osg/Notify>
#include <algorithm>
#include <set>
#include <map> //GWM July 2005 map is used in constraints.
#include <osgUtil/Tessellator> // tessellator triangulates the constrained triangles
#include <stdlib.h>
#include <iterator>
namespace osgUtil
{
//////////////////////////////////////////////////////////////////////////////////////
// MISC MATH FUNCTIONS
// Compute the circumcircle of a triangle (only x and y coordinates are used),
// return (Cx, Cy, r^2)
inline osg::Vec3 compute_circumcircle(
const osg::Vec3 &a,
const osg::Vec3 &b,
const osg::Vec3 &c)
{
float D =
(a.x() - c.x()) * (b.y() - c.y()) -
(b.x() - c.x()) * (a.y() - c.y());
float cx, cy, r2;
if(D==0.0)
{
// (Nearly) degenerate condition - either two of the points are equal (which we discount)
// or the three points are colinear. In this case we just determine the average of
// the three points as the centre for correctness, but squirt out a zero radius.
// This method will produce a triangulation with zero area, so we have to check later
cx = (a.x()+b.x()+c.x())/3.0;
cy = (a.y()+b.y()+c.y())/3.0;
r2 = 0.0;
}
else
{
cx =
(((a.x() - c.x()) * (a.x() + c.x()) +
(a.y() - c.y()) * (a.y() + c.y())) / 2 * (b.y() - c.y()) -
((b.x() - c.x()) * (b.x() + c.x()) +
(b.y() - c.y()) * (b.y() + c.y())) / 2 * (a.y() - c.y())) / D;
cy =
(((b.x() - c.x()) * (b.x() + c.x()) +
(b.y() - c.y()) * (b.y() + c.y())) / 2 * (a.x() - c.x()) -
((a.x() - c.x()) * (a.x() + c.x()) +
(a.y() - c.y()) * (a.y() + c.y())) / 2 * (b.x() - c.x())) / D;
// r2 = (c.x() - cx) * (c.x() - cx) + (c.y() - cy) * (c.y() - cy);
// the return r square is compared with r*r many times in an inner loop
// so for efficiency use the inefficient sqrt once rather than 30* multiplies later.
r2 = sqrt((c.x() - cx) * (c.x() - cx) + (c.y() - cy) * (c.y() - cy));
}
return osg::Vec3(cx, cy, r2);
}
// Test whether a point (only the x and y coordinates are used) lies inside
// a circle; the circle is passed as a vector: (Cx, Cy, r).
inline bool point_in_circle(const osg::Vec3 &point, const osg::Vec3 &circle)
{
float r2 =
(point.x() - circle.x()) * (point.x() - circle.x()) +
(point.y() - circle.y()) * (point.y() - circle.y());
return r2 <= circle.z()*circle.z();
// return r2 <= circle.z();
}
//
//////////////////////////////////////////////////////////////////////////////////////
// data type for vertex indices
typedef GLuint Vertex_index;
// CLASS: Edge
// This class describes an edge of a triangle (it stores vertex indices to the two
// endpoints).
class Edge {
public:
// Comparison object (for sorting)
struct Less
{
inline bool operator()(const Edge &e1, const Edge &e2) const
{
if (e1.ibs() < e2.ibs()) return true;
if (e1.ibs() > e2.ibs()) return false;
if (e1.ies() < e2.ies()) return true;
return false;
}
};
Edge(): ib_(0), ie_(0), ibs_(0), ies_(0), duplicate_(false) {}
Edge(Vertex_index ib, Vertex_index ie) : ib_(ib), ie_(ie), ibs_(osg::minimum(ib, ie)), ies_(osg::maximum(ib, ie)), duplicate_(false) {}
// first endpoint
inline Vertex_index ib() const { return ib_; }
// second endpoint
inline Vertex_index ie() const { return ie_; }
// first sorted endpoint
inline Vertex_index ibs() const { return ibs_; }
// second sorted endpoint
inline Vertex_index ies() const { return ies_; }
// get the "duplicate" flag
inline bool get_duplicate() const { return duplicate_; }
// set the "duplicate" flag
inline void set_duplicate(bool v) { duplicate_ = v; }
private:
Vertex_index ib_, ie_;
Vertex_index ibs_, ies_;
bool duplicate_;
};
// CLASS: Triangle
class Triangle
{
public:
Triangle():
a_(0),
b_(0),
c_(0) {}
Triangle(Vertex_index a, Vertex_index b, Vertex_index c, osg::Vec3Array *points)
: a_(a),
b_(b),
c_(c),
cc_(compute_circumcircle((*points)[a_], (*points)[b_], (*points)[c_]))
{
edge_[0] = Edge(a_, b_);
edge_[1] = Edge(b_, c_);
edge_[2] = Edge(c_, a_);
}
Triangle& operator = (const Triangle& rhs)
{
if (&rhs==this) return *this;
a_ = rhs.a_;
b_ = rhs.b_;
c_ = rhs.c_;
cc_ = rhs.cc_;
edge_[0] = rhs.edge_[0];
edge_[1] = rhs.edge_[1];
edge_[2] = rhs.edge_[2];
return *this;
}
inline Vertex_index a() const { return a_; }
inline Vertex_index b() const { return b_; }
inline Vertex_index c() const { return c_; }
inline void incrementa(const int delta) { a_+=delta; }
inline void incrementb(const int delta) { b_+=delta; }
inline void incrementc(const int delta) { c_+=delta; }
inline const Edge &get_edge(int idx) const { return edge_[idx]; }
inline const osg::Vec3 &get_circumcircle() const { return cc_; }
inline osg::Vec3 compute_centroid(const osg::Vec3Array *points) const
{
return ((*points)[a_] +(*points)[b_] + (*points)[c_])/3;
}
inline osg::Vec3 compute_normal(osg::Vec3Array *points) const
{
osg::Vec3 N = ((*points)[b_] - (*points)[a_]) ^ ((*points)[c_] - (*points)[a_]);
return N / N.length();
}
bool isedge(const unsigned int ip1,const unsigned int ip2) const
{ // is one of the edges of this triangle from ip1-ip2
bool isedge=ip1==a() && ip2==b();
if (!isedge)
{
isedge=ip1==b() && ip2==c();
if (!isedge)
{
isedge=ip1==c() && ip2==a();
}
}
return isedge;
}
// GWM July 2005 add test for triangle intersected by p1-p2.
// return true for unused edge
bool intersected(const unsigned int ip1,const unsigned int ip2,const osg::Vec2 p1 ,const osg::Vec2 p2,const int iedge, osg::Vec3Array *points) const
{
// return true if edge iedge of triangle is intersected by ip1,ip2
Vertex_index ie1,ie2;
if (iedge==0)
{
ie1=a();
ie2=b();
}
else if (iedge==1)
{
ie1=b();
ie2=c();
}
else if (iedge==2)
{
ie1=c();
ie2=a();
}
if (ip1==ie1 || ip2==ie1) return false;
if (ip1==ie2 || ip2==ie2) return false;
osg::Vec2 tp1((*points)[ie1].x(),(*points)[ie1].y());
osg::Vec2 tp2((*points)[ie2].x(),(*points)[ie2].y());
return intersect(tp1,tp2,p1,p2);
}
bool intersectedby(const osg::Vec2 p1,const osg::Vec2 p2,osg::Vec3Array *points) const {
// true if line [p1,p2] cuts at least one edge of this triangle
osg::Vec2 tp1((*points)[a()].x(),(*points)[a()].y());
osg::Vec2 tp2((*points)[b()].x(),(*points)[b()].y());
osg::Vec2 tp3((*points)[c()].x(),(*points)[c()].y());
bool ip=intersect(tp1,tp2,p1,p2);
if (!ip)
{
ip=intersect(tp2,tp3,p1,p2);
if (!ip)
{
ip=intersect(tp3,tp1,p1,p2);
}
}
return ip;
}
int whichEdge(osg::Vec3Array *points,const osg::Vec2 p1, const osg::Vec2 p2,
const unsigned int e1,const unsigned int e2) const
{
int icut=0;
// find which edge of triangle is cut by line (p1-p2) and is NOT e1-e2 indices.
// return 1 - cut is on edge b-c; 2==c-a
osg::Vec2 tp1((*points)[a()].x(),(*points)[a()].y()); // triangle vertices
osg::Vec2 tp2((*points)[b()].x(),(*points)[b()].y());
osg::Vec2 tp3((*points)[c()].x(),(*points)[c()].y());
bool ip=intersect(tp2,tp3,p1,p2);
if (ip && (a()==e1 || a()==e2)) { return 1;}
ip=intersect(tp3,tp1,p1,p2);
if (ip && (b()==e1 || b()==e2)) { return 2;}
ip=intersect(tp1,tp2,p1,p2);
if (ip && (c()==e1 || c()==e2)) { return 3;}
return icut;
}
bool usesVertex(const unsigned int ip) const
{
return ip==a_ || ip==b_ || ip==c_;
}
int lineBisectTest(const osg::Vec3 apt,const osg::Vec3 bpt,const osg::Vec3 cpt, const osg::Vec2 p2) const
{
osg::Vec2 vp2tp=p2-osg::Vec2(apt.x(), apt.y()); // vector from p1 to a.
// test is: cross product (z component) with ab,ac is opposite signs
// AND dot product with ab,ac has at least one positive value.
osg::Vec2 vecba=osg::Vec2(bpt.x(), bpt.y())-osg::Vec2(apt.x(), apt.y());
osg::Vec2 vecca=osg::Vec2(cpt.x(), cpt.y())-osg::Vec2(apt.x(), apt.y());
float cprodzba=vp2tp.x()*vecba.y() - vp2tp.y()*vecba.x();
float cprodzca=vp2tp.x()*vecca.y() - vp2tp.y()*vecca.x();
// OSG_WARN << "linebisect test " << " tri " << a_<<","<< b_<<","<< c_<<std::endl;
if (cprodzba*cprodzca<0)
{
// more tests - check dot products are at least partly parallel to test line.
osg::Vec2 tp1(bpt.x(),bpt.y()); // triangle vertices
osg::Vec2 tp2(cpt.x(),cpt.y());
osg::Vec2 tp3(apt.x(),apt.y());
bool ip=intersect(tp1,tp2,tp3,p2);
if (ip) return 1;
}
return 0;
}
int lineBisects(osg::Vec3Array *points, const unsigned int ip1, const osg::Vec2 p2) const
{
// return true if line starts at vertex <ip1> and lies between the 2 edges which meet at vertex
// <vertex> is that which uses index ip1.
// line is <vertex> to p2
// return value is 0 - no crossing; 1,2,3 - which edge of the triangle is cut.
if (a_==ip1)
{
// first vertex is the vertex - test that a_ to p2 lies beteen edges a,b and a,c
osg::Vec3 apt=(*points)[a_];
osg::Vec3 bpt=(*points)[b_];
osg::Vec3 cpt=(*points)[c_];
return lineBisectTest(apt,bpt,cpt,p2)?1:0;
}
else if (b_==ip1)
{
// second vertex is the vertex - test that b_ to p2 lies beteen edges a,b and a,c
osg::Vec3 apt=(*points)[b_];
osg::Vec3 bpt=(*points)[c_];
osg::Vec3 cpt=(*points)[a_];
return lineBisectTest(apt,bpt,cpt,p2)?2:0;
}
else if (c_==ip1)
{
// 3rd vertex is the vertex - test that c_ to p2 lies beteen edges a,b and a,c
osg::Vec3 apt=(*points)[c_];
osg::Vec3 bpt=(*points)[a_];
osg::Vec3 cpt=(*points)[b_];
return lineBisectTest(apt,bpt,cpt,p2)?3:0;
}
return 0;
}
private:
bool intersect(const osg::Vec2 p1,const osg::Vec2 p2,const osg::Vec2 p3,const osg::Vec2 p4) const
{
// intersection point of p1,p2 and p3,p4
// test from http://astronomy.swin.edu.au/~pbourke/geometry/lineline2d/
// the intersection must be internal to the lines, not an end point.
float det=((p4.y()-p3.y())*(p2.x()-p1.x())-(p4.x()-p3.x())*(p2.y()-p1.y()));
if (det!=0)
{
// point on line is P=p1+ua.(p2-p1) and Q=p3+ub.(p4-p3)
float ua=((p4.x()-p3.x())*(p1.y()-p3.y())-(p4.y()-p3.y())*(p1.x()-p3.x()))/det;
float ub=((p2.x()-p1.x())*(p1.y()-p3.y())-(p2.y()-p1.y())*(p1.x()-p3.x()))/det;
if (ua> 0.00 && ua< 1 && ub> 0.0000 && ub< 1)
{
return true;
}
}
return false;
}
Vertex_index a_;
Vertex_index b_;
Vertex_index c_;
osg::Vec3 cc_;
Edge edge_[3];
};
typedef std::list<Triangle> Triangle_list;
// comparison function for sorting sample points by the X coordinate
bool Sample_point_compare(const osg::Vec3 &p1, const osg::Vec3 &p2)
{
// replace pure sort by X coordinate with X then Y.
// errors can occur if the delaunay triangulation specifies 2 points at same XY and different Z
if (p1.x() != p2.x()) return p1.x() < p2.x();
if (p1.y() != p2.y()) return p1.y() < p2.y(); // GWM 30.06.05 - further rule if x coords are same.
OSG_INFO << "Two points are coincident at "<<p1.x() <<","<<p1.y() << std::endl;
return p1.z() < p2.z(); // never get here unless 2 points coincide
}
// container types
typedef std::set<Edge, Edge::Less> Edge_set;
DelaunayTriangulator::DelaunayTriangulator():
osg::Referenced()
{
}
DelaunayTriangulator::DelaunayTriangulator(osg::Vec3Array *points, osg::Vec3Array *normals):
osg::Referenced(),
points_(points),
normals_(normals)
{
}
DelaunayTriangulator::DelaunayTriangulator(const DelaunayTriangulator &copy, const osg::CopyOp &copyop):
osg::Referenced(copy),
points_(static_cast<osg::Vec3Array *>(copyop(copy.points_.get()))),
normals_(static_cast<osg::Vec3Array *>(copyop(copy.normals_.get()))),
prim_tris_(static_cast<osg::DrawElementsUInt *>(copyop(copy.prim_tris_.get())))
{
}
DelaunayTriangulator::~DelaunayTriangulator()
{
}
const Triangle * getTriangleWithEdge(const unsigned int ip1,const unsigned int ip2, const Triangle_list *triangles)
{ // find triangle in list with edge from ip1 to ip2...
Triangle_list::const_iterator trconnitr; // connecting triangle
int idx=0;
for (trconnitr=triangles->begin(); trconnitr!=triangles->end(); )
{
if (trconnitr->isedge (ip1,ip2))
{
// this is the triangle.
return &(*trconnitr);
}
++trconnitr;
idx++;
}
return NULL; //-1;
}
int DelaunayTriangulator::getindex(const osg::Vec3 &pt,const osg::Vec3Array *points)
{
// return index of pt in points (or -1)
for (unsigned int i=0; i<points->size(); i++)
{
if (pt.x()==(*points)[i].x() &&pt.y()==(*points)[i].y() )
{
return i;
}
}
return -1;
}
Triangle_list fillHole(osg::Vec3Array *points, std::vector<unsigned int> vindexlist)
{
// eg clockwise vertex neighbours around the hole made by the constraint
Triangle_list triangles; // returned list
osg::ref_ptr<osg::Geometry> gtess=new osg::Geometry; // add all the contours to this for analysis
osg::ref_ptr<osg::Vec3Array> constraintverts=new osg::Vec3Array;
osg::ref_ptr<osgUtil::Tessellator> tscx=new osgUtil::Tessellator; // this assembles all the constraints
for (std::vector<unsigned int>::iterator itint=vindexlist.begin(); itint!=vindexlist.end(); itint++)
{
// OSG_WARN<< "add point " << (*itint) << " at " << (*points)[*itint].x() << ","<< (*points)[*itint].y() <<std::endl;
constraintverts->push_back((*points)[*itint]);
}
unsigned int npts=vindexlist.size();
gtess->setVertexArray(constraintverts.get());
gtess->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POLYGON,0,npts));
tscx->setTessellationNormal(osg::Vec3(0.0,0.0,1.0));
tscx->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
tscx->setBoundaryOnly(false);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD); // the commonest tessellation is default, ODD. GE2 allows intersections of constraints to be found.
tscx->retessellatePolygons(*(gtess.get())); // this should insert extra vertices where constraints overlap
// extract triangles from gtess
unsigned int ipr;
for (ipr=0; ipr<gtess->getNumPrimitiveSets(); ipr++)
{
unsigned int ic;
osg::PrimitiveSet* prset=gtess->getPrimitiveSet(ipr);
// OSG_WARN<< "gtess set " << ipr << " nprims " << prset->getNumPrimitives() <<
// " type " << prset->getMode() << std::endl;
unsigned int pidx,pidx1,pidx2;
switch (prset->getMode()) {
case osg::PrimitiveSet::TRIANGLES:
for (ic=0; ic<prset->getNumIndices()-2; ic+=3)
{
if (prset->index(ic)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic)]);
pidx=points->size()-1;
}
else
{
pidx=vindexlist[prset->index(ic)];
}
if (prset->index(ic+1)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic+1)]);
pidx1=points->size()-1;
}
else
{
pidx1=vindexlist[prset->index(ic+1)];
}
if (prset->index(ic+2)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic+2)]);
pidx2=points->size()-1;
}
else
{
pidx2=vindexlist[prset->index(ic+2)];
}
triangles.push_back(Triangle(pidx, pidx1, pidx2, points));
// OSG_WARN<< "vert " << prset->index(ic) << " in array"<<std::endl;
}
break;
case osg::PrimitiveSet::TRIANGLE_STRIP: // 123, 234, 345...
for (ic=0; ic<prset->getNumIndices()-2; ic++)
{
if (prset->index(ic)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic)]);
pidx=points->size()-1;
} else {
pidx=vindexlist[prset->index(ic)];
}
if (prset->index(ic+1)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic+1)]);
pidx1=points->size()-1;
}
else
{
pidx1=vindexlist[prset->index(ic+1)];
}
if (prset->index(ic+2)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic+2)]);
pidx2=points->size()-1;
}
else
{
pidx2=vindexlist[prset->index(ic+2)];
}
if (ic%2==0)
{
triangles.push_back(Triangle(pidx, pidx1, pidx2, points));
}
else
{
triangles.push_back(Triangle(pidx1, pidx, pidx2, points));
}
// OSG_WARN<< "vert " << prset->index(ic) << " in array"<<std::endl;
}
break;
case osg::PrimitiveSet::TRIANGLE_FAN:
{
if (prset->index(0)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(0)]);
pidx=points->size()-1;
}
else
{
pidx=vindexlist[prset->index(0)];
}
// OSG_WARN<< "tfan has " << prset->getNumIndices() << " indices"<<std::endl;
for (ic=1; ic<prset->getNumIndices()-1; ic++)
{
if (prset->index(ic)>=npts)
{
// this is an added point.
points->push_back((*constraintverts)[prset->index(ic)]);
pidx1=points->size()-1;
}
else
{
pidx1=vindexlist[prset->index(ic)];
}
if (prset->index(ic+1)>=npts)
{ // this is an added point.
points->push_back((*constraintverts)[prset->index(ic+1)]);
pidx2=points->size()-1;
}
else
{
pidx2=vindexlist[prset->index(ic+1)];
}
triangles.push_back(Triangle(pidx, pidx1, pidx2, points));
}
}
break;
default:
OSG_WARN<< "WARNING set " << ipr << " nprims " << prset->getNumPrimitives() <<
" type " << prset->getMode() << " Type not triangle, tfan or strip"<< std::endl;
break;
}
}
return triangles;
}
template <typename TVector>
void removeIndices( TVector& elements, unsigned int index )
{
typename TVector::iterator itr = elements.begin();
while ( itr != elements.end() )
{
if ( (*itr)==index )
{ // remove entirely
itr = elements.erase(itr);
}
else
{
if ((*itr)>index) --(*itr); // move indices down 1
++itr; // next index
}
}
}
void DelaunayConstraint::removeVerticesInside(const DelaunayConstraint *dco)
{ /** remove vertices from this which are internal to dco.
* retains potins that are extremely close to edge of dco
* defined as edge of dco subtends>acs(0.999999)
*/
int nrem=0;
osg::Vec3Array *vertices= dynamic_cast< osg::Vec3Array*>(getVertexArray());
if (vertices)
{
for (osg::Vec3Array::iterator vitr=vertices->begin(); vitr!=vertices->end(); )
{
if (dco->contains(*vitr))
{
unsigned int idx=vitr-vertices->begin(); // index of vertex
// remove vertex index from all the primitives
for (unsigned int ipr=0; ipr<getNumPrimitiveSets(); ipr++)
{
osg::PrimitiveSet* prset=getPrimitiveSet(ipr);
switch (prset->getType())
{
case osg::PrimitiveSet::DrawElementsUBytePrimitiveType:
removeIndices( *static_cast<osg::DrawElementsUByte *>(prset), idx );
break;
case osg::PrimitiveSet::DrawElementsUShortPrimitiveType:
removeIndices( *static_cast<osg::DrawElementsUShort *>(prset), idx );
break;
case osg::PrimitiveSet::DrawElementsUIntPrimitiveType:
removeIndices( *static_cast<osg::DrawElementsUInt *>(prset), idx );
break;
default:
OSG_WARN << "Invalid prset " <<ipr<< " tp " << prset->getType() << " types PrimitiveType,DrawArraysPrimitiveType=1 etc" << std::endl;
break;
}
}
vitr=vertices->erase(vitr);
nrem++;
}
else
{
vitr++;
}
}
}
}
void DelaunayConstraint::merge(DelaunayConstraint *dco)
{
unsigned int ipr;
if (dco) { // 16 Dec 2006 just in case you pass in a NULL pointer
osg::Vec3Array* vmerge=dynamic_cast<osg::Vec3Array*>(getVertexArray());
if (!vmerge) vmerge=new osg::Vec3Array;
setVertexArray(vmerge);
for ( ipr=0; ipr<dco->getNumPrimitiveSets(); ipr++)
{
osg::PrimitiveSet* prset=dco->getPrimitiveSet(ipr);
osg::DrawArrays *drarr=dynamic_cast<osg::DrawArrays *> (prset);
if (drarr)
{
// need to add the offset of vmerge->size to each prset indices.
unsigned int noff=vmerge->size();
unsigned int n1=drarr->getFirst(); // usually 0
unsigned int numv=drarr->getCount(); //
addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_LOOP,n1+noff,numv));
}
}
osg::Vec3Array* varr=dynamic_cast<osg::Vec3Array*>(dco->getVertexArray());
if (varr) vmerge->insert(vmerge->end(),varr->begin(),varr->end());
}
}
void DelaunayTriangulator::_uniqueifyPoints()
{
std::sort( points_->begin(), points_->end() );
osg::ref_ptr<osg::Vec3Array> temppts = new osg::Vec3Array;
// This won't work... must write our own unique() that compares only the first
// two terms of a Vec3 for equivalency
//std::insert_iterator< osg::Vec3Array > ti( *(temppts.get()), temppts->begin() );
//std::unique_copy( points_->begin(), points_->end(), ti );
osg::Vec3Array::iterator p = points_->begin();
osg::Vec3 v = *p;
// Always push back the first point
temppts->push_back( (v = *p));
for( ; p != points_->end(); p++ )
{
if( v[0] == (*p)[0] && v[1] == (*p)[1] )
continue;
temppts->push_back( (v = *p));
}
points_->clear();
std::insert_iterator< osg::Vec3Array > ci(*(points_.get()),points_->begin());
std::copy( temppts->begin(), temppts->end(), ci );
}
osgUtil::DelaunayConstraint *getconvexhull(osg::Vec3Array *points)
{ // fits the 'rubberband' around the 2D points for uses as a delaunay constraint.
osg::ref_ptr<osgUtil::DelaunayConstraint> dcconvexhull=new osgUtil::DelaunayConstraint; // make
// convex hull around all the points
// start from first point (at minx); proceed to last x and back
osg::Vec3Array *verts=new osg::Vec3Array; // the hull points
verts->push_back(*(points->begin()) ); // min x/y point is guaranteed to be on the hull
verts->push_back(*(points->begin()+1) ); // second low x/y point is first length to be tested
for (osg::Vec3Array::iterator vit=(points->begin()+2); vit!=points->end(); vit++) {
// check if point lies outside the current last line segment
bool ok=1;
while (ok && verts->size()>1) {
osg::Vec3 lastseg=*(verts->end()-2)-*(verts->end()-1);
osg::Vec3 thisseg=(*vit)-*(verts->end()-1);
float cosang=(lastseg^thisseg).z();
if (cosang <0.0) { // pop off last point - *vit is further out hull
verts->pop_back();
} else { ok=0;}
}
verts->push_back(*vit ); // next low x/y point is next length to be tested
// check if the previous external angle is >180 - then remove previous point
}
for (osg::Vec3Array::reverse_iterator rvit=points->rbegin()+1; rvit!=points->rend(); rvit++) {
// check if point lies outside the current last line segment
bool ok=1;
while (ok && verts->size()>1) {
osg::Vec3 lastseg=*(verts->end()-2)-*(verts->end()-1);
osg::Vec3 thisseg=(*rvit)-*(verts->end()-1);
float cosang=(lastseg^thisseg).z();
if (cosang <0.0) { // pop off last point - *rvit is further out hull
verts->pop_back();
} else { ok=0;}
}
if ((*rvit)!=*(verts->begin())) verts->push_back(*rvit ); // next low x/y point is next length to be tested
// check if the previous external angle is >180 - then remove previous point
}
dcconvexhull->setVertexArray(verts);
dcconvexhull->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::LINE_LOOP,0,verts->size()) );
return dcconvexhull.release();
}
bool DelaunayTriangulator::triangulate()
{
// check validity of input array
if (!points_.valid())
{
OSG_WARN << "Warning: DelaunayTriangulator::triangulate(): invalid sample point array" << std::endl;
return false;
}
osg::Vec3Array *points = points_.get();
if (points->size() < 1)
{
OSG_WARN << "Warning: DelaunayTriangulator::triangulate(): too few sample points" << std::endl;
return false;
}
// Eliminate duplicate lat/lon points from input coordinates.
_uniqueifyPoints();
// initialize storage structures
Triangle_list triangles;
Triangle_list discarded_tris;
// GWM July 2005 add constraint vertices to terrain
linelist::iterator linitr;
for (linitr=constraint_lines.begin();linitr!=constraint_lines.end();linitr++)
{
DelaunayConstraint* dc=(*linitr).get();
const osg::Vec3Array* vercon= dynamic_cast<const osg::Vec3Array*>(dc->getVertexArray());
if (vercon)
{
int nadded=0;
for (unsigned int icon=0;icon<vercon->size();icon++)
{
osg::Vec3 p1=(*vercon)[icon];
int idx=getindex(p1,points_.get());
if (idx<0)
{ // only unique vertices are permitted.
points_->push_back(p1); // add non-unique constraint points to triangulation
nadded++;
}
else
{
OSG_WARN << "DelaunayTriangulator: ignore a duplicate point at "<< p1.x()<< " " << p1.y() << std::endl;;
}
}
}
// OSG_WARN<< "constraint size "<<vercon->size()<<" " <<nadded<< std::endl;
}
// GWM July 2005 end
// pre-sort sample points
OSG_INFO << "DelaunayTriangulator: pre-sorting sample points\n";
std::sort(points->begin(), points->end(), Sample_point_compare);
// 24.12.06 add convex hull of points to force sensible outline.
osg::ref_ptr<osgUtil::DelaunayConstraint> dcconvexhull=getconvexhull(points);
addInputConstraint(dcconvexhull.get());
// set the last valid index for the point list
GLuint last_valid_index = points->size() - 1;
// find the minimum and maximum x values in the point list
float minx = (*points)[0].x();
float maxx = (*points)[last_valid_index].x();
// find the minimum and maximum y values in the point list
float miny = (*points)[0].y();
float maxy = miny;
OSG_INFO << "DelaunayTriangulator: finding minimum and maximum Y values\n";
osg::Vec3Array::const_iterator mmi;
for (mmi=points->begin(); mmi!=points->end(); ++mmi)
{
if (mmi->y() < miny) miny = mmi->y();
if (mmi->y() > maxy) maxy = mmi->y();
}
// add supertriangle vertices to the point list
// gwm added 1.05* to ensure that supervertices are outside the domain of points.
// original value could make 2 coincident points for regular arrays of x,y,h data.
// this mod allows regular spaced arrays to be used.
// 16 Dec 2006 this increase in size encourages the supervertex triangles to be long and thin
// thus ensuring that the convex hull of the terrain points are edges in the delaunay triangulation
// the values do however result in a small loss of numerical resolution.
points_->push_back(osg::Vec3(minx - .10*(maxx - minx), miny - .10*(maxy - miny), 0));
points_->push_back(osg::Vec3(maxx + .10*(maxx - minx), miny - .10*(maxy - miny), 0));
points_->push_back(osg::Vec3(maxx + .10*(maxx - minx), maxy + .10*(maxy - miny), 0));
points_->push_back(osg::Vec3(minx - .10*(maxx - minx), maxy + .10*(maxy - miny), 0));
// add supertriangles to triangle list
triangles.push_back(Triangle(last_valid_index+1, last_valid_index+2, last_valid_index+3, points));
triangles.push_back(Triangle(last_valid_index+4, last_valid_index+1, last_valid_index+3, points));
// begin triangulation
GLuint pidx = 0;
osg::Vec3Array::const_iterator i;
OSG_INFO << "DelaunayTriangulator: triangulating vertex grid (" << (points->size()-3) <<" points)\n";
for (i=points->begin(); i!=points->end(); ++i, ++pidx)
{
// don't process supertriangle vertices
if (pidx > last_valid_index) break;
Edge_set edges;
// iterate through triangles
Triangle_list::iterator j, next_j;
for (j=triangles.begin(); j!=triangles.end(); j = next_j)
{
next_j = j;
++next_j;
// get the circumcircle (x,y centre & radius)
osg::Vec3 cc = j->get_circumcircle();
// OPTIMIZATION: since points are pre-sorted by the X component,
// check whether we can discard this triangle for future operations
float xdist = i->x() - cc.x();
// this is where the circumcircles radius rather than R^2 is faster.
// original code used r^2 and needed to test xdist*xdist>cc.z && i->x()>cc.x().
if ((xdist ) > cc.z() )
{
discarded_tris.push_back(*j); // these are not needed for further tests as no more
// points will ever lie inside this triangle.
triangles.erase(j);
}
else
{
// if the point lies in the triangle's circumcircle then add
// its edges to the edge list and remove the triangle
if (point_in_circle(*i, cc))
{
for (int ei=0; ei<3; ++ei)
{
std::pair<Edge_set::iterator, bool> result = edges.insert(j->get_edge(ei));
if (!result.second)
{
// cast away constness of a set element, which is
// safe in this case since the set_duplicate is
// not used as part of the Less operator.
Edge& edge = const_cast<Edge&>(*(result.first));
// not clear why this change is needed? But prevents removal of twice referenced edges??
// edge.set_duplicate(true);
edge.set_duplicate(!edge.get_duplicate());
}
}
triangles.erase(j);
}
}
}
// remove duplicate edges and add new triangles
Edge_set::iterator ci;
for (ci=edges.begin(); ci!=edges.end(); ++ci)
{
if (!ci->get_duplicate())
{
triangles.push_back(Triangle(pidx, ci->ib(), ci->ie(), points));
}
}
}
// dec 2006 we used to remove supertriangle vertices here, but then we cant strictly use the supertriangle
// vertices to find intersections of constraints with terrain, so moved to later.
OSG_INFO << "DelaunayTriangulator: finalizing and cleaning up structures\n";
// rejoin the two triangle lists
triangles.insert(triangles.begin(), discarded_tris.begin(), discarded_tris.end());
// GWM July 2005 eliminate any triangle with an edge crossing a constraint line
// http://www.geom.uiuc.edu/~samuelp/del_project.html
// we could also implement the sourcecode in http://gts.sourceforge.net/reference/gts-delaunay-and-constrained-delaunay-triangulations.html
// this uses the set of lines which are boundaries of the constraints, including points
// added to the contours by tessellation.
for (linelist::iterator dcitr=constraint_lines.begin();dcitr!=constraint_lines.end();dcitr++)
{
//DelaunayConstraint *dc=(*dcitr).get();
const osg::Vec3Array* vercon = dynamic_cast<const osg::Vec3Array*>((*dcitr)->getVertexArray());
if (vercon)
{
for (unsigned int ipr=0; ipr<(*dcitr)->getNumPrimitiveSets(); ipr++)
{
const osg::PrimitiveSet* prset=(*dcitr)->getPrimitiveSet(ipr);
if (prset->getMode()==osg::PrimitiveSet::LINE_LOOP ||
prset->getMode()==osg::PrimitiveSet::LINE_STRIP)
{
// loops or strips
// start with the last point on the loop
unsigned int ip1=getindex((*vercon)[prset->index (prset->getNumIndices()-1)],points_.get());
for (unsigned int i=0; i<prset->getNumIndices(); i++)
{
unsigned int ip2=getindex((*vercon)[prset->index(i)],points_.get());
if (i>0 || prset->getMode()==osg::PrimitiveSet::LINE_LOOP)
{
// dont check edge from end to start
// for strips
// 2 points on the constraint
bool edgused=false;// first check for exact edge indices are used.
Triangle_list::iterator titr;
int it=0;
for (titr=triangles.begin(); titr!=triangles.end() && !edgused; ++titr)
{
//check that the edge ip1-ip2 is not already part of the triangulation.
if (titr->isedge(ip1,ip2)) edgused=true;
if (titr->isedge(ip2,ip1)) edgused=true;
// if (edgused) OSG_WARN << "Edge used in triangle " << it << " " <<
// titr->a()<<","<< titr->b()<<","<< titr->c()<< std::endl;
it++;
}
if (!edgused)
{
// then check for intermediate triangles, erase them and replace with constrained triangles.
// find triangle with point ip1 where the 2 edges from ip1 contain the line p1-p2.
osg::Vec2 p1((*points_)[ip1].x(),(*points_)[ip1].y()); // a constraint line joins p1-p2
osg::Vec2 p2((*points_)[ip2].x(),(*points_)[ip2].y());
int ntr=0;
std::vector<const Triangle *> trisToDelete; // array of triangles to delete from terrain.
// form 2 lists of vertices for the edges of the hole created.
// The hole joins vertex ip1 to ip2, and one list of edges lies to the left
// of the line ip1-ip2m the other to the right.
// a list of vertices forming 2 halves of the removed triangles.
// which in turn are filled in with the tessellator.
for (titr=triangles.begin(); titr!=triangles.end(); )
{
int icut=titr->lineBisects(points_.get(),ip1,p2);
// OSG_WARN << "Testing triangle " << ntr << " "<< ip1 << " ti " <<
// titr->a()<< ","<<titr->b() <<"," <<titr->c() << std::endl;
if (icut>0)
{
// triangle titr starts the constraint edge
std::vector<unsigned int> edgeRight, edgeLeft;
edgeRight.push_back(ip1);
edgeLeft.push_back(ip1);
// OSG_WARN << "hole first " << edgeLeft.back()<< " rt " << edgeRight.back()<< std::endl;
trisToDelete.push_back(&(*titr));
// now find the unique triangle that shares the defined edge
unsigned int e1, e2; // indices of ends of test triangle titr
if (icut==1)
{
// icut=1 implies vertex a is not involved
e1=titr->b(); e2=titr->c();
}
else if (icut==2)
{
e1=titr->c(); e2=titr->a();
}
else if (icut==3)
{
e1=titr->a(); e2=titr->b();
}
edgeRight.push_back(e2);
edgeLeft.push_back(e1);
// OSG_WARN << icut << "hole edges " << edgeLeft.back()<< " rt " << edgeRight.back()<< std::endl;
const Triangle *tradj=getTriangleWithEdge(e2,e1, &triangles);
if (tradj)
{
while (tradj && !tradj->usesVertex(ip2) && trisToDelete.size()<999)
{
trisToDelete.push_back(tradj);
icut=tradj->whichEdge(points_.get(),p1,p2,e1,e2);
// OSG_WARN << ntr << " cur triedge " << icut << " " << ip1 <<
// " to " << ip2 << " tadj " << tradj->a()<< ","<<tradj->b() <<","
// <<tradj->c() <<std::endl;
if (icut==1) {e1=tradj->b(); e2=tradj->c();} // icut=1 implies vertex a is not involved
else if (icut==2) {e1=tradj->c(); e2=tradj->a();}
else if (icut==3) {e1=tradj->a(); e2=tradj->b();}
if (edgeLeft.back()!=e1 && edgeRight.back()==e2 && e1!=ip2) {
edgeLeft.push_back(e1);
} else if(edgeRight.back()!=e2 && edgeLeft.back()==e1 && e2!=ip2) {
edgeRight.push_back(e2);
} else {
if (!tradj->usesVertex(ip2)) OSG_WARN << "tradj error " << tradj->a()<< " , " << tradj->b()<< " , " << tradj->c()<< std::endl;
}
const Triangle *previousTradj = tradj;
tradj=getTriangleWithEdge(e2,e1, &triangles);
if (tradj == previousTradj) {
tradj = 0;
}
}
if (trisToDelete.size()>=900) {
OSG_WARN << " found " << trisToDelete.size() << " adjacent tris " <<std::endl;
}
}
// both lines end at ip2 point.
edgeLeft.push_back(ip2);
edgeRight.push_back(ip2);
if (tradj) trisToDelete.push_back(tradj);
// OSG_WARN << icut << "hole last " << edgeLeft.back()<< " rt " << edgeRight.back()<< std::endl;
Triangle_list constrainedtris=fillHole(points_.get(),edgeLeft);
triangles.insert(triangles.begin(), constrainedtris.begin(), constrainedtris.end());
constrainedtris=fillHole(points_.get(),edgeRight);
triangles.insert(triangles.begin(), constrainedtris.begin(), constrainedtris.end());
}
++titr;
ntr++;
}
// remove the triangles list
Triangle_list::iterator tri; // counts through triangles
for (tri=triangles.begin(); tri!=triangles.end(); )
{
bool deleted=false;
for (std::vector<const Triangle *>::iterator deleteTri=trisToDelete.begin();
deleteTri!=trisToDelete.end(); )
{
if (&(*tri)==*deleteTri)
{
deleted=true;
tri=triangles.erase(tri);
deleteTri=trisToDelete.erase(deleteTri); // 24.12.06 remove from delete list.
} else {deleteTri++; }
}
if (!deleted) ++tri;
}
}
} // strip test
ip1=ip2; // next edge of line
}
}
}
}
}
// GWM Sept 2005 end
// dec 2006 remove supertriangle vertices - IF we have added some internal vertices (see fillholes)
// then these may not be the last vertices in the list.
// } else { // remove 3 super-triangle vertices more completely, moving any reference indices down.
Triangle_list::iterator tri;
GLuint supertriend = last_valid_index+4;
for (tri=triangles.begin(); tri!=triangles.end();)
{ // look for triangles using the supertriangle indices or >super indices and move down by 3.
if ((tri->a() > last_valid_index && tri->a() <= supertriend) ||
(tri->b() > last_valid_index && tri->b() <= supertriend ) ||
(tri->c() > last_valid_index && tri->c() <= supertriend )) {
tri=triangles.erase(tri);
} else { // move down by 3 tests
if (tri->a() > last_valid_index) { // move index down 4
tri->incrementa(-4);
}
if (tri->b() > last_valid_index) { // move down 4
tri->incrementb(-4);
}
if (tri->c() > last_valid_index) { // move down 4 -- correction 21.12.06- was b() should test index c()
tri->incrementc(-4);
}
++tri; // only increment tri here as the other path increments tri when tri=triangles.erase.
}
}
// remove 3 supertriangle vertices from points. They may not be the last vertices in points if
// extra points have been inserted by the constraint re-triangulation.
points->erase(points->begin()+last_valid_index+1,points->begin()+last_valid_index+5);
//last_valid_index = points->size()-1; // the last valid vertex is last point.
// end of dec 2006 changes.
// initialize index storage vector
std::vector<GLuint> pt_indices;
pt_indices.reserve(triangles.size() * 3);
// build osg primitive
OSG_INFO << "DelaunayTriangulator: building primitive(s)\n";
Triangle_list::const_iterator ti;
for (ti=triangles.begin(); ti!=triangles.end(); ++ti)
{
// don't add this triangle to the primitive if it shares any vertex with
// the supertriangle triangles have already been removed.
// Don't need this test: ti->a() <= last_valid_index && ti->b() <= last_valid_index && ti->c() <= last_valid_index &&
// Don't add degenerate (zero radius) triangles
if ( ti->get_circumcircle().z()>0.0)
{
if (normals_.valid())
{
(normals_.get())->push_back(ti->compute_normal(points));
}
pt_indices.push_back(ti->a());
pt_indices.push_back(ti->b());
pt_indices.push_back(ti->c());
}
}
// LF August 2011 fix crash when no triangle is created
if (!pt_indices.size())
{
OSG_WARN << "Warning: DelaunayTriangulator::triangulate(): no triangle generated" << std::endl;
return false;
}
prim_tris_ = new osg::DrawElementsUInt(GL_TRIANGLES, pt_indices.size(), &(pt_indices.front()));
OSG_INFO << "DelaunayTriangulator: process done, " << prim_tris_->getNumPrimitives() << " triangles remain\n";
return true;
}
void DelaunayTriangulator::removeInternalTriangles(DelaunayConstraint *dc )
{
if (dc) { // 16.12.06 just in case....
// Triangle_list *triangles
// remove triangle from terrain prim_tris_ internal to each constraintline
// and move to the constraint line to make an alternative geometry,
// possibly with alternative texture, and texture map
int ndel=0;
osg::Vec3Array::iterator normitr;
if( normals_.valid() )
normitr = normals_->begin();
// OSG_WARN << "DelaunayTriangulator: removeinternals, " << std::endl;
for (osg::DrawElementsUInt::iterator triit=prim_tris_->begin(); triit!=prim_tris_->end(); )
{
// triangle joins points_[itr, itr+1, itr+2]
Triangle tritest((*triit), *(triit+1), *(triit+2), points_.get());
if ( dc->contains(tritest.compute_centroid( points_.get()) ) )
{
// centroid is inside the triangle, so IF inside linear, remove
// OSG_WARN << "DelaunayTriangulator: remove, " << (*triit) << "," << *(triit+1) <<","<<*(triit+2)<< std::endl;
dc->addtriangle((*triit), *(triit+1), *(triit+2));
triit=prim_tris_->erase(triit);
triit=prim_tris_->erase(triit);
triit=prim_tris_->erase(triit);
if (normals_.valid())
{
// erase the corresponding normal
normitr=normals_->erase(normitr);
}
ndel++;
}
else
{
if (normals_.valid())
{
normitr++;
}
triit+=3;
}
}
OSG_INFO << "end of test dc, deleted " << ndel << std::endl;
}
}
//=== DelaunayConstraint functions
float DelaunayConstraint::windingNumber(const osg::Vec3 &testpoint) const
{
// return winding number of loop around testpoint. Only in 2D, x-y coordinates assumed!
float theta=0; // sum of angles subtended by the line array - the winding number
const osg::Vec3Array *vertices= dynamic_cast<const osg::Vec3Array*>(getVertexArray());
if (vertices)
{
for (unsigned int ipr=0; ipr<getNumPrimitiveSets(); ipr++)
{
const osg::PrimitiveSet* prset=getPrimitiveSet(ipr);
if (prset->getMode()==osg::PrimitiveSet::LINE_LOOP)
{
// nothing else loops
// start with the last point on the loop
const osg::Vec3 prev=(*vertices)[prset->index (prset->getNumIndices()-1)];
osg::Vec3 pi(prev.x()-testpoint.x(),prev.y()-testpoint.y(),0);
pi.normalize();
for (unsigned int i=0; i<prset->getNumIndices(); i++)
{
const osg::Vec3 curp=(*vertices)[prset->index (i)];
osg::Vec3 edge(curp.x()-testpoint.x(),curp.y()-testpoint.y(),0);
edge.normalize();
double cth=edge*pi;
if (cth<=-0.99999 )
{
// testpoint is on edge and between 2 points
return 0; //
}
else
{
if (cth<0.99999)
{
float dang=(cth<1 && cth>-1)?acos(edge*pi):0; // this is unsigned angle
float zsign=edge.x()*pi.y()-pi.x()*edge.y(); // z component of..(edge^pi).z();
if (zsign>0) theta+=dang; // add the angle subtended appropriately
else if (zsign<0) theta-=dang;
}
}
pi=edge;
}
}
}
}
return theta/osg::PI/2.0; // should be 0 or 2 pi.
}
osg::DrawElementsUInt *DelaunayConstraint::makeDrawable()
{
if (_interiorTris.empty())
{
return 0;
}
// initialize index storage vector for internal triangles.
std::vector<GLuint> pt_indices;
pt_indices.reserve(_interiorTris.size() * 3);
trilist::const_iterator ti;
for (ti=_interiorTris.begin(); ti!=_interiorTris.end(); ++ti)
{
// if (normals_.valid()) {
// (normals_.get())->push_back(ti->compute_normal(points));
// }
pt_indices.push_back((*ti)[0]);
pt_indices.push_back((*ti)[1]);
pt_indices.push_back((*ti)[2]);
}
prim_tris_ = new osg::DrawElementsUInt(GL_TRIANGLES, pt_indices.size(), &(pt_indices.front()));
return prim_tris_.get();
}
bool DelaunayConstraint::contains(const osg::Vec3 &testpoint) const
{
// true if point is internal to the loop.
float theta=windingNumber(testpoint); // sum of angles subtended by the line array - the winding number
return fabs(theta)>0.9; // should be 0 or 1 (or 2,3,4 for very complex not permitted loops).
}
bool DelaunayConstraint::outside(const osg::Vec3 &testpoint) const
{
// true if point is outside the loop.
float theta=windingNumber(testpoint); // sum of angles subtended by the line array - the winding number
return fabs(theta)<.05; // should be 0 if outside.
}
void DelaunayConstraint::addtriangle(int i1, int i2, int i3)
{
// a triangle joins vertices i1,i2,i3 in the points of the delaunay triangles.
// points is the array of poitns in the triangulator;
// add triangle to the constraint
int *ip=new int[3];
ip[0]=i1;
ip[1]=i2;
ip[2]=i3;
_interiorTris.push_back(ip);
}
osg::Vec3Array* DelaunayConstraint::getPoints(const osg::Vec3Array *points)
{
//points_ is the array of points that can be used to render the triangles in this DC.
osg::ref_ptr<osg::Vec3Array> points_=new osg::Vec3Array;
trilist::iterator ti;
for (ti=_interiorTris.begin(); ti!=_interiorTris.end(); ++ti) {
int idx=0;
int ip[3]={-1,-1,-1};
// find if points[i1/i2/i3] already in the vertices points_
for (osg::Vec3Array::iterator ivert=points_->begin(); ivert!=points_->end(); ivert++)
{
if (ip[0]<0 && *ivert==(*points)[(*ti)[0]])
{
(*ti)[0]=ip[0]=idx;
}
if (ip[1]<0 && *ivert==(*points)[(*ti)[1]])
{
(*ti)[1]=ip[1]=idx;
}
if (ip[2]<0 && *ivert==(*points)[(*ti)[2]])
{
(*ti)[2]=ip[2]=idx;
}
idx++;
}
if (ip[0]<0)
{
points_->push_back((*points)[(*ti)[0]]);
(*ti)[0]=ip[0]=points_->size()-1;
}
if (ip[1]<0)
{
points_->push_back((*points)[(*ti)[1]]);
(*ti)[1]=ip[1]=points_->size()-1;
}
if (ip[2]<0)
{
points_->push_back((*points)[(*ti)[2]]);
(*ti)[2]=ip[2]=points_->size()-1;
}
}
makeDrawable();
return points_.release();
}
void DelaunayConstraint::handleOverlaps(void)
{
// use tessellator to interpolate crossing vertices.
osg::ref_ptr<osgUtil::Tessellator> tscx=new osgUtil::Tessellator; // this assembles all the constraints
tscx->setTessellationType(osgUtil::Tessellator::TESS_TYPE_GEOMETRY);
tscx->setBoundaryOnly(true);
tscx->setWindingType( osgUtil::Tessellator::TESS_WINDING_ODD);
// ODD chooses the winding =1, NOT overlapping areas of constraints.
// nb this includes all the edges where delaunay constraints meet
// draw a case to convince yourself!.
tscx->retessellatePolygons(*this); // find all edges
}
DelaunayConstraint::~DelaunayConstraint()
{
trilist::const_iterator ti;
for (ti=_interiorTris.begin(); ti!=_interiorTris.end(); ++ti)
{
delete[] *ti;
}
}
} // namespace osgutil
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