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cgal/Old_Packages/bops/include/CGAL/bops_simple_polygons_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_simple_polygons_2.C
// package : bops (2.2)
// source : include/CGAL/bops_simple_polygons_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_SIMPLE_POLYGONS_2_C
#define CGAL_BOPS_SIMPLE_POLYGONS_2_C
#ifndef CGAL_CFG_NO_AUTOMATIC_TEMPLATE_INCLUSION
#include<CGAL/bops_simple_polygons_2.h>
#endif
CGAL_BEGIN_NAMESPACE
#if 0
template <class I>
//Bops_Simple_Polygons_2<I>::Intersection_type
int
Bops_Simple_Polygons_2<I>::calc_intersection_type(int) const {
typename I::Bbox a_box= I::get_Bbox(_pgon1);
typename I::Bbox b_box= I::get_Bbox(_pgon2);
if( a_box == b_box ) {
if( _pgon1 == _pgon2 ) return is_identical;
}
if( !I::do_overlap(a_box, b_box) ) return is_empty;
if( I::box_is_contained_in_box( a_box, b_box) )
return A_is_subset_of_B;
if( I::box_is_contained_in_box( b_box, a_box) )
return B_is_subset_of_A;
typename Polygon_Container::const_iterator it;
int sum1= 0, n1= _pgon1.size();
for( it= _pgon1.vertices_begin(); it != _pgon1.vertices_end(); it++)
sum1 += I::has_on_bounded_side(_pgon2, *it) ? +1 : -1;
if( sum1 == n1 || sum1 == -n1 ) {
int sum2= 0, n2= _pgon2.size();
for( it= _pgon2.vertices_begin(); it != _pgon2.vertices_end(); it++)
sum2 += I::has_on_bounded_side(_pgon1,*it) ? +1 : -1;
if( sum2 == n2|| sum2 == -n2) {
if( sum1 == -n1 && sum2 == -n2 ) // polygons are separated
// iff no intersections occur, otherwise return 4
return !_inter_res.size() ? is_empty : is_intersection;
if( sum1 == n1 && sum2 == -n2 ) // A is subset B
return A_is_subset_of_B;
if( sum1 == -n1 && sum2 == n2 ) // B is subset A
return B_is_subset_of_A;
}
}
return is_intersection; // intersections occur
}
#endif
template<class I>
void Bops_Simple_Polygons_2_Intersection<I> ::
perform(void)
{
/* performs the intersection algorithm on the colored DCEL */
/* handle special cases */
switch( _pgon_intersection_type ) {
case is_empty:
return;
case is_identical:
case A_is_subset_of_B:
_result.push_back(I::Make_object(_pgon1) );
return;
case B_is_subset_of_A:
_result.push_back(I::Make_object(_pgon2) );
return;
case is_intersection:
break;
}
_Dcel_Color search_color(_RED_AND_BLACK);
/* handle general case */
std::list<edge_iterator> elist;
edge_iterator e;
vertex_iterator v;
_Polygon_2 pgon;
face_iterator f;
for(f= dcel.face_begin(); f != dcel.face_end(); f++) {
if( (*f).color() == search_color ) { /* walk around f */
pgon= walk_around(f);
_result.push_back(I::Make_object(pgon) );
}
}
/* Now we have found all possible polygons.
Last but not least we have to search for edges and vertices, which
have both colors, i.e. they are part of the intersection result.
*/
typedef typename Bops_Simple_Polygons_2_Intersection<I>::Segment_2 Segment_local;
Segment_local *seg;
for( e= dcel.begin(); e != dcel.end(); e++ ) { /* for_all_edges( edge e ) */
if( is_unmarked(e) && (*e).color() == search_color ) {
seg= new Segment_local( dcel.point((*e).V1()), dcel.point((*e).V2()) );
_result.push_back(I::Make_object(*seg) );
mark( (*e).V1() );
mark( (*e).V2() );
delete seg;
}
}
for(v= dcel.vertex_begin(); v != dcel.vertex_end(); v++) {
if( is_unmarked(v) && (*v).color() == search_color )
_result.push_back( I::Make_object(dcel.point(v)) );
}
return;
}
template<class I>
void Bops_Simple_Polygons_2_Difference<I> :: perform(void)
{
/* performs the DIFFERENCE algorithm on the colored DCEL */
_Polygon_2 pgon;
/* handle special cases */
switch( _pgon_intersection_type ) {
case is_empty:
_result.push_back(I::Make_object(_pgon1) );
return;
case is_identical:
case A_is_subset_of_B:
return;
case B_is_subset_of_A:
_result.push_back(I::Make_object(_pgon1) );
I::reverse_orientation(_pgon2); // we found a hole
_result.push_back(I::Make_object(_pgon2) );
return;
case is_intersection:
break;
}
_Dcel_Color search_color(_RED);
/* handle general case */
edge_iterator e;
vertex_iterator v;
face_iterator f;
for(f= dcel.face_begin(); f != dcel.face_end(); f++) {
if( (*f).color() == search_color ) { /* walk around f */
pgon= walk_around(f);
_result.push_back(I::Make_object(pgon) );
}
}
typedef typename Bops_Simple_Polygons_2_Difference<I>::Segment_2 Segment_local;
Segment_local *seg;
for( e= dcel.begin(); e != dcel.end(); e++ ) {
if( is_unmarked(e) && (*e).color() == search_color ) {
seg= new Segment_local( dcel.point((*e).V1()), dcel.point((*e).V2()) );
_result.push_back(I::Make_object(*seg) );
mark( (*e).V1() );
mark( (*e).V2() );
delete seg;
}
}
for(v= dcel.vertex_begin(); v != dcel.vertex_end(); v++) {
if( is_unmarked(v) && (*v).color() == search_color )
_result.push_back( I::Make_object(dcel.point(v)) );
}
return;
}
template<class I>
void Bops_Simple_Polygons_2_Union<I> :: perform(void)
{
/* performs the UNION algorithm on the colored DCEL */
/* handle special cases */
switch( _pgon_intersection_type ) {
case is_empty: /* empty intersection ==> return both polygons */
_result.push_back(I::Make_object(_pgon1) );
_result.push_back(I::Make_object(_pgon2) );
return;
case is_identical: /* pgon1 == pgon2 */
_result.push_back(I::Make_object(_pgon1) );
return;
case A_is_subset_of_B: /* pgon1 subset of pgon2, hence pgon1 is a hole */
_result.push_back(I::Make_object(_pgon2) );
I::reverse_orientation(_pgon1); /* we found a hole */
_result.push_back(I::Make_object(_pgon1) );
return;
case B_is_subset_of_A: /* pgon2 subset of pgon1, hence pgon2 is a hole */
_result.push_back(I::Make_object(_pgon1) );
I::reverse_orientation(_pgon2); /* we found a hole */
_result.push_back(I::Make_object(_pgon2) );
return;
case is_intersection:
break;
}
typedef typename _Polygon_2::Vertex_const_iterator polygon_vertex_iterator;
polygon_vertex_iterator p1it = _pgon1.left_vertex();
polygon_vertex_iterator p2it = _pgon2.left_vertex();
polygon_vertex_iterator pit = (*p1it).x() < (*p2it).x() ? p1it : p2it ;
/* pt = ... the outmost to the left point of polygons A and B */
_Point_2 pt = *pit;
vertex_iterator vit = dcel.find(pt);
/* edgeE = ... the edge starting at vit with largest slope (and
thus on the outer boundary */
edge_iterator lit, eit, ait= dcel.begin(vit);
marked[(*ait).index()]= true;
_Point_2 pt1, pt2, pt3;
lit = ait;
for( eit= dcel.next(ait,vit); eit != ait; eit= dcel.next(eit, vit) ) {
pt1= dcel.point(vit);
pt2= dcel.point((*eit).opposite_vertex(vit) ) ;
pt3= dcel.point((*lit).opposite_vertex(vit) ) ;
if( is_leftturn(pt1, pt3, pt2) ) lit = eit;
}
/* faceF = ... the face of *lit without color */
face_iterator faceFit= (*(*lit).F1()).color() == _UNCOLORED ?
(*lit).F1() : (*lit).F2();
/* get the outer boundary */
_Polygon_2 pgon= walk_around(faceFit,false);
_result.push_back(I::Make_object(pgon) );
/* get the holes */
for( eit= dcel.begin(); eit != dcel.end(); eit++ ) { /*for_all_edges(edge e)*/
if( marked[(*eit).index()] == false ) {
if( (*(*eit).F1()).color() == _UNCOLORED ) {
pgon = walk_around((*eit).F1(),false);
_result.push_back(I::Make_object(pgon) );
}
if( (*(*eit).F2()).color() == _UNCOLORED ) {
pgon= walk_around((*eit).F2(),false);
_result.push_back(I::Make_object(pgon) );
}
}
}
return;
}
CGAL_END_NAMESPACE
#endif /* CGAL_BOPS_SIMPLE_POLYGONS_2_C */
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