Generator/random_segments2.cpp

// CGAL example program for the generic segment generator
// using precomputed point locations.
 
#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
#include <algorithm>
#include <vector>
#include <CGAL/point_generators_2.h>
#include <CGAL/function_objects.h>
#include <CGAL/Join_input_iterator.h>
#include <CGAL/Counting_iterator.h>
#include <cassert>
 
using namespace CGAL;
 
typedef Exact_predicates_inexact_constructions_kernel K;
typedef K::Point_2                                Point;
typedef K::Segment_2                              Segment;
typedef Points_on_segment_2<Point>                PG;
typedef Creator_uniform_2< Point, Segment>        Creator;
typedef Join_input_iterator_2< PG, PG, Creator>   Segm_iterator;
typedef Counting_iterator<Segm_iterator,Segment>  Count_iterator;
typedef std::vector<Segment>                      Vector;
 
int main() {
    // Create test segment set. Prepare a vector for 100 segments.
    Vector segs;
    segs.reserve(100);
 
    // A horizontal like fan.
    PG p1( Point(-250, -50), Point(-250, 50),50);   // Point generator.
    PG p2( Point( 250,-250), Point( 250,250),50);
    Segm_iterator  t1( p1, p2);                     // Segment generator.
    Count_iterator t1_begin( t1);                   // Finite range.
    Count_iterator t1_end( t1, 50);
    std::copy( t1_begin, t1_end, std::back_inserter(segs));
 
    // A vertical like fan.
    PG p3( Point( -50,-250), Point(  50,-250),50);
    PG p4( Point(-250, 250), Point( 250, 250),50);
    Segm_iterator  t2( p3, p4);
    Count_iterator t2_begin( t2);
    Count_iterator t2_end( t2, 50);
    std::copy( t2_begin, t2_end, std::back_inserter(segs));
 
    assert( segs.size() == 100);
    for ( Vector::iterator i = segs.begin(); i != segs.end(); i++){
        assert( i->source().x() <=  250);
        assert( i->source().x() >= -250);
        assert( i->source().y() <=  250);
        assert( i->source().y() >= -250);
        assert( i->target().x() <=  250);
        assert( i->target().x() >= -250);
        assert( i->target().y() <=  250);
        assert( i->target().y() >= -250);
    }
    return 0;
}