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cgal/Old_Packages/bops/include/CGAL/bops_Convex_Polygon_2.C

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// ======================================================================
//
// Copyright (c) 1997 The CGAL Consortium
//
// This software and related documentation is part of an INTERNAL release
// of the Computational Geometry Algorithms Library (CGAL). It is not
// intended for general use.
//
// ----------------------------------------------------------------------
//
// release :
// release_date : 1999, October 01
//
// file : include/CGAL/bops_Convex_Polygon_2.C
// package : bops (2.2)
// source : include/CGAL/bops_Convex_Polygon_2.C
// revision : $Revision$
// revision_date : $Date$
// author(s) : Wolfgang Freiseisen <Wolfgang.Freiseisen@risc.uni-linz.ac.at>
//
// coordinator : RISC Linz
// (Wolfgang Freiseisen <wfreisei@risc.uni-linz.ac.at>)
//
//
// ======================================================================
#ifndef CGAL_BOPS_CONVEX_POLYGON_2_C
#define CGAL_BOPS_CONVEX_POLYGON_2_C
#include <CGAL/bops_Convex_Polygon_2.h>
CGAL_BEGIN_NAMESPACE
#define ORIGINAL // now use this
#ifdef ORIGINAL
template <class R_type, class Container>
Polygon_2<Polygon_traits_2<R_type>, Container>
Convex_Intersection(
Polygon_2<Polygon_traits_2<R_type>, Container> P,
Polygon_2<Polygon_traits_2<R_type>, Container> Q)
{
typedef Polygon_2<Polygon_traits_2<R_type>,Container> My_Polygon;
typedef Point_2<R_type> My_Point;
typedef Segment_2<R_type> My_Segment;
typedef Vector_2<R_type> My_Vector;
enum tInFlag {unknown, Pin, Qin};
int pSize, qSize; // size of polygons
int aAdv, bAdv; // number of iterations over each polygon
My_Point ipoint,targ; // variables for intersection
My_Polygon::Vertex_circulator pCir, qCir, pCir1, qCir1;
// circulators over polygons
Orientation bHA, aHB; // orientation of polygons
typedef typename R_type::FT FT;
FT cross; // cross product
tInFlag inflag; // which polygon is inside
My_Vector aVec, bVec; // vectors for computation
My_Segment s1,s2,iseg; // segments to check intersection
Object result; // result of intersection of s1 and s2
std::list<My_Point> pt_list; // points forming solution-polynom
int lastaAdv, lastbAdv; // variables to avoid endless loop
//check correct orientation for algorithm
if (!(P.orientation()==COUNTERCLOCKWISE)) P.reverse_orientation();
if (!(Q.orientation()==COUNTERCLOCKWISE)) Q.reverse_orientation();
// initialize variables
lastaAdv = lastbAdv = 0;
aAdv = bAdv = 0;
pSize = P.size(); qSize = Q.size();
inflag = unknown;
pCir = pCir1 = P.vertices_circulator ();
qCir = qCir1 = Q.vertices_circulator ();
pCir1 = pCir; qCir1 = qCir;
pCir1--; qCir1--;
do
{
// create vectors
aVec = *pCir-*pCir1; bVec=*qCir-*qCir1;
// calculate 'cross-product'
cross = aVec[0]*bVec[1]-aVec[1]*bVec[0];
// get orientation
bHA = orientation(*pCir1, *pCir, *qCir);
aHB = orientation(*qCir1, *qCir, *pCir);
// create segments for intersection
Segment_2<R_type> s1(*pCir1,*pCir);
Segment_2<R_type> s2(*qCir1,*qCir);
//check for intersection
if (do_intersect(s1,s2))
{
// get type of intersection
result = intersection(s1,s2);
// if result is a point, insert in result-polynom
if (assign(ipoint, result))
{
// if first intersection start algorithm
if (inflag == unknown) aAdv=bAdv=0;
if (aHB==LEFTTURN) {inflag=Pin;}
else if (aHB==RIGHTTURN) {inflag=Qin;}
else
{
// aHB is collinear
if (*pCir == *qCir)
{
//the endpoints of the segments are the same
//check which polynom is inside
if (orientation(*pCir,*(qCir++),*(pCir++))==RIGHTTURN) {inflag = Qin;}
else
{inflag=Pin;}
pCir--;qCir--;
} // end of pCir==qCir
else if (ipoint == *pCir)
{
//intersection-point is end of P, i.e. it lies on Q
if (orientation(ipoint,*(pCir++),*qCir)==RIGHTTURN)
{inflag=Pin;}
else
{inflag = Qin;}
pCir--;
} // end of ipoint==pCir
else
{
//point of intersection is end of Q, i.e. it lies on P
if (orientation(ipoint,*pCir,*(qCir++))==LEFTTURN)
{inflag=Qin;}
else
{inflag=Pin;}
qCir--;
} // end of default
} //end of else
if (!pt_list.empty())
{if ((pt_list.back()!=ipoint)&&(pt_list.front()!=ipoint)) pt_list.push_back(ipoint);}
else
pt_list.push_back(ipoint);
} // end of point intersection
else
{
// segment intersection
if (assign(iseg,result))
{
// make sure that pCir or qCir is target
if ((iseg.source()==*pCir) || (iseg.source()==*qCir))
{
targ=iseg.source();
}
else
{targ=iseg.target();}
// if P and Q have the same endpoint
if (*pCir == *qCir)
{
if (orientation(*pCir,*(qCir++),*(pCir++))==RIGHTTURN)
{ inflag = Qin;}
else
{ inflag = Pin;}
pCir--;qCir--;
} // end of if (*pCir == *qCir)
else if (targ==*pCir)
{
// segment of intersection is on end of P
if ((pt_list.back()!=targ)&&(pt_list.front()!=targ)) pt_list.push_back(targ);
inflag = Pin;
} //end of else if
else
{
if ((pt_list.back()!=targ)&&(pt_list.front()!=targ)) pt_list.push_back(targ);
inflag = Qin;
} // end of else
} //end of segment intersection
} //end of else for intersection
} //end of intersection
if (cross >= FT(0) )
{
if (bHA == LEFTTURN)
{
if ((inflag == Pin)&&(pt_list.back()!=*pCir)&&(pt_list.front()!=*pCir)) pt_list.push_back(*pCir);
aAdv++; pCir++; pCir1++;
// abortion check
lastaAdv++; lastbAdv=0;
}
else
{
if ((inflag == Qin)&&(pt_list.back()!=*qCir)&&(pt_list.front()!=*qCir)) pt_list.push_back(*qCir);
bAdv++; qCir++; qCir1++;
// abortion check
lastbAdv++; lastaAdv=0;
}
}
else
{
if (aHB == LEFTTURN)
{
if ((inflag == Qin)&&(pt_list.back()!=*qCir)&&(pt_list.front()!=*qCir)) pt_list.push_back(*qCir);
bAdv++; qCir++; qCir1++;
// abortion check
lastbAdv++; lastaAdv=0;
}
else
{
if ((inflag == Pin)&&(pt_list.back()!=*pCir)&&(pt_list.front()!=*pCir)) pt_list.push_back(*pCir);
aAdv++; pCir++; pCir1++;
// abortion check
lastaAdv++; lastbAdv=0;
}
}
} //end of do-loop
while (((aAdv < pSize) || (bAdv < qSize))&&(lastaAdv <= pSize)&&(lastbAdv<=qSize));
//create result polygon
My_Polygon final(pt_list.begin(),pt_list.end());
if (inflag == unknown)
{
//polygons do not intersect
if (P.bounded_side(*qCir)==ON_BOUNDED_SIDE) return Q;
else if (Q.bounded_side(*pCir)==ON_BOUNDED_SIDE) return P;
else return final;
}
else
{
return final;
}
}
#else
template <class R_type, class Container>
Polygon_2<Polygon_traits_2<R_type>, Container>
Convex_Intersection(
Polygon_2<Polygon_traits_2<R_type>, Container> P,
Polygon_2<Polygon_traits_2<R_type>, Container> Q
)
{
typedef Polygon_2<Polygon_traits_2<R_type>,Container> My_Polygon;
typedef Point_2<R_type> My_Point;
typedef Segment_2<R_type> My_Segment;
typedef Vector_2<R_type> My_Vector;
typedef typename R_type::FT FT;
enum tInFlag {unknown, Pin, Qin};
int pSize, qSize; // size of polygons
int aAdv, bAdv; // number of iterations over each polygon
My_Point ipoint,targ; // variables for intersection
My_Polygon::Vertex_circulator pCir, qCir, pCir1, qCir1;
// circulators over polygons
Orientation bHA, aHB; // orientation of polygons
FT cross; // cross product
tInFlag inflag; // which polygon is inside
My_Vector aVec, bVec; // vectors for computation
My_Segment s1,s2,iseg; // segments to check intersection
Object result; // result of intersection of s1 and s2
std::list<My_Point> pt_list; // points forming solution-polynom
int lastaAdv, lastbAdv; // variables to avoid endless loop
//check correct orientation for algorithm
if (!(P.orientation()==COUNTERCLOCKWISE)) P.reverse_orientation();
if (!(Q.orientation()==COUNTERCLOCKWISE)) Q.reverse_orientation();
// initialize variables
lastaAdv = lastbAdv = 0;
aAdv = bAdv = 0;
pSize = P.size(); qSize = Q.size();
inflag = unknown;
pCir = pCir1 = P.vertices_circulator ();
qCir = qCir1 = Q.vertices_circulator ();
pCir1 = pCir; qCir1 = qCir;
pCir1--; qCir1--;
do {
// create vectors
aVec = *pCir-*pCir1; bVec=*qCir-*qCir1;
// calculate 'cross-product'
cross = aVec[0]*bVec[1]-aVec[1]*bVec[0];
// get orientation
bHA = orientation(*pCir1, *pCir, *qCir);
aHB = orientation(*qCir1, *qCir, *pCir);
// create segments for intersection
Segment_2<R_type> s1(*pCir1,*pCir);
Segment_2<R_type> s2(*qCir1,*qCir);
//check for intersection
if (do_intersect(s1,s2)) {
// get type of intersection
result = intersection(s1,s2);
// if result is a point, insert in result-polynom
if (assign(ipoint, result)) {
// if first intersection start algorithm
//if (inflag == unknown) aAdv=bAdv=0;
if (aHB==LEFTTURN) {inflag=Pin;}
else if (aHB==RIGHTTURN) {inflag=Qin;}
else {
// aHB is collinear
if (*pCir == *qCir) {
//the endpoints of the segments are the same
//check which polynom is inside
if (orientation(*pCir,*(qCir++),*(pCir++))==RIGHTTURN) {
inflag = Qin;
}
else {
inflag=Pin;
}
pCir--;qCir--;
} // end of pCir==qCir
else if (ipoint == *pCir) {
//intersection-point is end of P, i.e. it lies on Q
if (orientation(ipoint,*(pCir++),*qCir)==RIGHTTURN) {
inflag=Pin;
}
else {
inflag = Qin;
}
pCir--;
} // end of ipoint==pCir
else {
//point of intersection is end of Q, i.e. it lies on P
if (orientation(ipoint,*pCir,*(qCir++))==LEFTTURN) {
inflag=Qin;
}
else {
inflag=Pin;
}
qCir--;
} // end of default
} //end of else
if (!pt_list.empty() ) {
if ((pt_list.back()!=ipoint)&&(pt_list.front()!=ipoint))
pt_list.push_back(ipoint);
}
else
pt_list.push_back(ipoint);
} // end of point intersection
else {
// segment intersection
if (assign(iseg,result)) {
// make sure that pCir or qCir is target
targ= ((iseg.source()==*pCir) || (iseg.source()==*qCir)) ?
iseg.source() : iseg.target();
// if P and Q have the same endpoint
if (*pCir == *qCir) {
if (orientation(*pCir,*(qCir++),*(pCir++))==RIGHTTURN) {
inflag = Qin;
}
else {
inflag = Pin;
}
pCir--;qCir--;
} // end of if (*pCir == *qCir)
else if (targ==*pCir) {
// segment of intersection is on end of P
if ((pt_list.back()!=targ)&&(pt_list.front()!=targ))
pt_list.push_back(targ);
inflag = Pin;
} //end of else if
else {
if ((pt_list.back()!=targ)&&(pt_list.front()!=targ))
pt_list.push_back(targ);
inflag = Qin;
} // end of else
} //end of segment intersection
} //end of else for intersection
} //end of intersection
if (cross >= FT(0)) {
if (bHA == LEFTTURN) {
if ((inflag == Pin)&&(pt_list.back()!=*pCir)&&(pt_list.front()!=*pCir))
pt_list.push_back(*pCir);
aAdv++; pCir++; pCir1++;
// abortion check
lastaAdv++; lastbAdv=0;
}
else {
if ((inflag == Qin)&&(pt_list.back()!=*qCir)&&(pt_list.front()!=*qCir))
pt_list.push_back(*qCir);
bAdv++; qCir++; qCir1++;
// abortion check
lastbAdv++; lastaAdv=0;
}
}
else {
if (aHB == LEFTTURN) {
if ((inflag == Qin)&&(pt_list.back()!=*qCir)&&(pt_list.front()!=*qCir))
pt_list.push_back(*qCir);
bAdv++; qCir++; qCir1++;
// abortion check
lastbAdv++; lastaAdv=0;
}
else {
if ((inflag == Pin)&&(pt_list.back()!=*pCir)&&(pt_list.front()!=*pCir))
pt_list.push_back(*pCir);
aAdv++; pCir++; pCir1++;
// abortion check
lastaAdv++; lastbAdv=0;
}
}
} //end of do-loop
while (((aAdv < pSize) || (bAdv < qSize))&&(lastaAdv <= pSize)&&(lastbAdv<=qSize));
//create result polygon
My_Polygon final(pt_list.begin(),pt_list.end());
if (inflag == unknown) {
//polygons do not intersect
if (P.bounded_side(*qCir)==ON_BOUNDED_SIDE)
return Q;
else if (Q.bounded_side(*pCir)==ON_BOUNDED_SIDE)
return P;
else
return final;
}
else {
return final;
}
}
#endif
template< class I>
Bops_Convex_Polygons_2<I>::InFlag
Bops_Convex_Polygons_2<I>::handleIntersectionPoint(
const Point& pt, const Orientation& aHB
)
{
InFlag inflag;
if ( aHB == LEFTTURN )
inflag= Pin;
else if ( aHB == RIGHTTURN )
inflag= Qin;
else { // aHB is collinear
if (*_pCir == *_qCir) {
//the endpoints of the segments are the same
//check which polynom is inside
inflag= is_leftturn(*_pCir, *(_qCir++), *(_pCir++)) ? Pin : Qin;
_pCir--;
_qCir--;
} // end of pCir==qCir
else if (pt == *_pCir) {
//intersection-point is end of P, i.e. it lies on Q
inflag= is_leftturn(pt, *(_pCir++), *_qCir) ? Qin : Pin;
_pCir--;
} // end of ipoint==pCir
else {
//point of intersection is end of Q, i.e. it lies on P
inflag= is_leftturn(pt, *_pCir, *(_qCir++)) ? Qin : Pin;
_qCir--;
} // end of default
} //end of else
insert(pt);
return inflag;
}
template< class I>
Bops_Convex_Polygons_2<I>::InFlag
Bops_Convex_Polygons_2<I>::handleIntersectionSegment(const Segment& seg)
{
InFlag inflag;
// make sure that pCir or qCir is target
_Point_2 targ= (seg.source()==*_pCir || seg.source()==*_qCir) ?
seg.source() : seg.target();
// if P and Q have the same endpoint
if (*_pCir == *_qCir) {
inflag= is_leftturn(*_pCir,*(_qCir++),*(_pCir++)) ? Pin : Qin; // is_rightturn
_pCir--; _qCir--;
} // end of if (*pCir == *qCir)
else { // segment of intersection is on end of P or Q
inflag= (targ==*_pCir) ? Pin : Qin;
insert(targ);
} // end of else
return inflag;
}
template< class I>
void Bops_Convex_Polygons_2<I>::mainProcedure()
{
Orientation bHA, aHB; // orientation of polygons
NT cross; // cross product
Segment s1,s2,iseg; // segments to check intersection
Point ipoint, targ; // variables for intersection
Vector aVec, bVec; // vectors for computation
CGAL::Object result; // result of intersection of s1 and s2
do {
// create vectors
aVec= *_pCir-*_pCir1;
bVec= *_qCir-*_qCir1;
// calculate 'cross-product'
cross = aVec[0]*bVec[1]-aVec[1]*bVec[0];
// get orientation
bHA = orientation(*_pCir1, *_pCir, *_qCir);
aHB = orientation(*_qCir1, *_qCir, *_pCir);
// create segments for intersection
Segment s1(*_pCir1,*_pCir);
Segment s2(*_qCir1,*_qCir);
//check for intersection
if (do_intersect(s1,s2)) {
// get type of intersection
result = intersection(s1,s2);
// if result is a point, insert in result-polynom
if ( assign(ipoint, result) )
_inflag= handleIntersectionPoint(ipoint, aHB);
else if ( assign(iseg,result) ) // segment intersection
_inflag= handleIntersectionSegment( iseg );
else // empty intersection
;
} //end of intersection
bool is_in_A;
if (cross >= NT(0))
is_in_A= (bHA == LEFTTURN) ? true : false;
else
is_in_A= !(aHB == LEFTTURN) ? true : false;
if( is_in_A == true ) {
conditional_insert(Pin, _inflag, *_pCir);
advancePolygonA();
}
else { // otherwise is_in_B == true
conditional_insert(Qin, _inflag, *_qCir);
advancePolygonB();
}
} //end of do-loop
while ( !wentAround() );
return;
}
CGAL_END_NAMESPACE
#endif // CGAL_BOPS_CONVEX_POLYGON_2_C
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