/Src/Dependencies/Boost/libs/geometry/doc/src/examples/algorithms/difference.cpp
http://hadesmem.googlecode.com/ · C++ · 90 lines · 37 code · 19 blank · 34 comment · 0 complexity · 440ab51ffe98430be02df4076264440f MD5 · raw file
- // Boost.Geometry (aka GGL, Generic Geometry Library)
- // QuickBook Example
- // Copyright (c) 2011 Barend Gehrels, Amsterdam, the Netherlands.
- // Use, modification and distribution is subject to the Boost Software License,
- // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
- // http://www.boost.org/LICENSE_1_0.txt)
- //[difference
- //` Shows how to subtract one polygon from another polygon
- #include <iostream>
- #include <list>
- #include <boost/geometry.hpp>
- #include <boost/geometry/geometries/point_xy.hpp>
- #include <boost/geometry/geometries/polygon.hpp>
- #include <boost/geometry/domains/gis/io/wkt/wkt.hpp>
- #include <boost/foreach.hpp>
- /*<-*/ #include "create_svg_overlay.hpp" /*->*/
- int main()
- {
- typedef boost::geometry::model::polygon<boost::geometry::model::d2::point_xy<double> > polygon;
- polygon green, blue;
- boost::geometry::read_wkt(
- "POLYGON((2 1.3,2.4 1.7,2.8 1.8,3.4 1.2,3.7 1.6,3.4 2,4.1 3,5.3 2.6,5.4 1.2,4.9 0.8,2.9 0.7,2 1.3)"
- "(4.0 2.0, 4.2 1.4, 4.8 1.9, 4.4 2.2, 4.0 2.0))", green);
- boost::geometry::read_wkt(
- "POLYGON((4.0 -0.5 , 3.5 1.0 , 2.0 1.5 , 3.5 2.0 , 4.0 3.5 , 4.5 2.0 , 6.0 1.5 , 4.5 1.0 , 4.0 -0.5))", blue);
- std::list<polygon> output;
- boost::geometry::difference(green, blue, output);
- int i = 0;
- std::cout << "green - blue:" << std::endl;
- BOOST_FOREACH(polygon const& p, output)
- {
- std::cout << i++ << ": " << boost::geometry::area(p) << std::endl;
- }
- /*<-*/ create_svg("difference_a.svg", green, blue, output); /*->*/
- output.clear();
- boost::geometry::difference(blue, green, output);
- i = 0;
- std::cout << "blue - green:" << std::endl;
- BOOST_FOREACH(polygon const& p, output)
- {
- std::cout << i++ << ": " << boost::geometry::area(p) << std::endl;
- }
- /*<-*/ create_svg("difference_b.svg", green, blue, output); /*->*/
- return 0;
- }
- //]
- //[difference_output
- /*`
- Output:
- [pre
- green - blue:
- 0: 0.02375
- 1: 0.542951
- 2: 0.0149697
- 3: 0.226855
- 4: 0.839424
- [$img/algorithms/difference_a.png]
- blue - green:
- 0: 0.525154
- 1: 0.015
- 2: 0.181136
- 3: 0.128798
- 4: 0.340083
- 5: 0.307778
- [$img/algorithms/difference_b.png]
- ]
- */
- //]