CGAL 4.7 - Intersecting Sequences of dD Iso-oriented Boxes: Box_intersection_d/box_grid.cpp

\( \newcommand{\E}{\mathrm{E}} \) \( \newcommand{\A}{\mathrm{A}} \) \( \newcommand{\R}{\mathrm{R}} \) \( \newcommand{\N}{\mathrm{N}} \) \( \newcommand{\Q}{\mathrm{Q}} \) \( \newcommand{\Z}{\mathrm{Z}} \) \( \def\ccSum #1#2#3{ \sum_{#1}^{#2}{#3} } \def\ccProd #1#2#3{ \sum_{#1}^{#2}{#3} }\)

CGAL 4.7 - Intersecting Sequences of dD Iso-oriented Boxes

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Box_intersection_d/box_grid.cpp
#include <CGAL/box_intersection_d.h>
#include <vector>
#include <algorithm>
#include <iterator>
#include <cassert>
typedef CGAL::Box_intersection_d::Box_d<int,2> Box;
// coordinates for 9 boxes of a grid
int p[9*4] = { 0,0,1,1, 1,0,2,1, 2,0,3,1, // lower
0,1,1,2, 1,1,2,2, 2,1,3,2, // middle
0,2,1,3, 1,2,2,3, 2,2,3,3};// upper
// 9 boxes
Box boxes[9] = { Box( p, p+ 2), Box( p+ 4, p+ 6), Box( p+ 8, p+10),
Box( p+12, p+14), Box( p+16, p+18), Box( p+20, p+22),
Box( p+24, p+26), Box( p+28, p+30), Box( p+32, p+34)};
// 2 selected boxes as query; center and upper right
Box query[2] = { Box( p+16, p+18), Box( p+32, p+34)};
// callback function object writing results to an output iterator
template <class OutputIterator>
struct Report {
OutputIterator it;
Report( OutputIterator i) : it(i) {} // store iterator in object
// We write the id-number of box a to the output iterator assuming
// that box b (the query box) is not interesting in the result.
void operator()( const Box& a, const Box&) { *it++ = a.id(); }
};
template <class Iter> // helper function to create the function object
Report<Iter> report( Iter it) { return Report<Iter>(it); }
int main() {
// run the intersection algorithm and store results in a vector
std::vector<std::size_t> result;
CGAL::box_intersection_d( boxes, boxes+9, query, query+2,
report( std::back_inserter( result)));
// sort, check, and show result
std::sort( result.begin(), result.end());
std::size_t check1[13] = {0,1,2,3,4,4,5,5,6,7,7,8,8};
assert(result.size() == 13 && std::equal(check1,check1+13,result.begin()));
std::copy( result.begin(), result.end(),
std::ostream_iterator<std::size_t>( std::cout, " "));
std::cout << std::endl;
// run it again but for different cutoff value and half-open boxes
result.clear();
CGAL::box_intersection_d( boxes, boxes+9, query, query+2,
report( std::back_inserter( result)),
std::ptrdiff_t(1),
CGAL::Box_intersection_d::HALF_OPEN);
// sort, check, and show result
std::sort( result.begin(), result.end());
std::size_t check2[2] = {4,8};
assert(result.size() == 2 && std::equal(check2, check2+2, result.begin()));
std::copy( result.begin(), result.end(),
std::ostream_iterator<std::size_t>( std::cout, " "));
std::cout << std::endl;
return 0;
}