(C++) BoostGeometryExample15

 

 

Boost.Geometry example 15: Obtain the intersection of a polygon and linestring is a Boost.Geometry example.

Technical facts

 

Application type(s)

• Desktop application

Operating system(s) or programming environment(s)

• Lubuntu 15.04 (vivid)

IDE(s):

• Qt Creator 3.1.1

Project type:

• GUI application

C++ standard:

• C++11

Compiler(s):

• G++ 4.9.2

Libraries used:

• Qt: version 5.4.1 (32 bit)
• STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppBoostGeometryExample15/CppBoostGeometryExample15.pro

 

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exists(../../ConsoleApplication.pri) {   include(../../ConsoleApplication.pri) } !exists(../../ConsoleApplication.pri) {   QT += core   QT += gui   greaterThan(QT_MAJOR_VERSION, 4): QT += widgets   CONFIG   += console   CONFIG   -= app_bundle   TEMPLATE = app   CONFIG(release, debug|release) {     DEFINES += NDEBUG NTRACE_BILDERBIKKEL   }   QMAKE_CXXFLAGS += -std=c++11 -Wall -Wextra -Weffc++   unix {     QMAKE_CXXFLAGS += -Werror   } } exists(../../Libraries/Boost.pri) {   include(../../Libraries/Boost.pri) } !exists(../../Libraries/Boost.pri) {   win32 {     INCLUDEPATH += \       ../../Libraries/boost_1_55_0   } } SOURCES += main.cpp

 

 

 

 

 

./CppBoostGeometryExample15/main.cpp

 

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#include <cassert> #include <iostream> #include <vector> #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Weffc++" #pragma GCC diagnostic ignored "-Wunused-local-typedefs" #pragma GCC diagnostic ignored "-Wunused-variable" #include <boost/geometry.hpp> //#include <boost/geometry/algorithms/correct.hpp> //#include <boost/geometry/algorithms/equals.hpp> //#include <boost/geometry/algorithms/intersection.hpp> //#include <boost/geometry/geometries/linestring.hpp> #include <boost/geometry/geometries/point_xy.hpp> //#include <boost/geometry/geometries/polygon.hpp> //#include <boost/geometry/io/wkt/read.hpp> //#include <boost/geometry/io/wkt/write.hpp> #include <boost/geometry/io/wkt/wkt.hpp> #pragma GCC diagnostic pop /* +   *---*        +               + |   |   |        |               | +   |   |        + *---*         +   +-* |   | A |        | | B |         |     | +   |   |    +   + *---*     =   +   +-* |   |   |        |               | +   +---+        +               + |                |               | +-+-+-+-+-+      +-+-+-+-+-+     +-+-+-+-+-+ */ int main() {   typedef boost::geometry::model::d2::point_xy<double> Coordinat2D;   typedef boost::geometry::model::linestring<Coordinat2D> Linestring;   typedef boost::geometry::model::polygon<Coordinat2D> Polygon;   typedef std::vector<Linestring> Linestrings;   //Create polygon A   Polygon a;   boost::geometry::read_wkt(     "POLYGON((4.0 4.0,4.0 1.0,2.0 1.0,2.0 4.0))",     a   );   boost::geometry::correct(a);   //Create linestring B   Linestring b;   boost::geometry::read_wkt(     "LINESTRING(1.0 3.0,3.0 3.0,3.0 2.0,1.0 2.0)",     b   );   boost::geometry::correct(b);   //Create intersection   Linestrings intersections;   boost::geometry::intersection(a,b,intersections);   assert(intersections.size() == 1);   //Extract the only intersection   const auto found = intersections[0];   Linestring expected;   boost::geometry::read_wkt(     "LINESTRING(2.0 3.0,3.0 3.0,3.0 2.0,2.0 2.0)",     expected   );   std::cout     << "Found:" << '\n'     << "As WKT: " << boost::geometry::wkt<decltype(found)>(found) << '\n'     << "#points: " << found.size() << '\n'   ;   for (const auto point: found)   {     std::cout << '(' << boost::geometry::get<0>(point)       << ',' << boost::geometry::get<1>(point) << ')'       << '\n'     ;   }   std::cout     << "Expected:" << '\n'     << "As WKT: " << boost::geometry::wkt<decltype(expected)>(expected) << '\n'     << "#points: " << expected.size() << '\n';   for (const auto point: expected)   {     std::cout << '(' << boost::geometry::get<0>(point)       << ',' << boost::geometry::get<1>(point) << ')'       << '\n'     ;   }   assert(found.size() == expected.size());   assert(boost::geometry::equals(found,expected)); } /* Screen output: Found: As WKT: LINESTRING(2 3,3 3,3 2,2 2) #points: 4 (2,3) (3,3) (3,2) (2,2) Expected: As WKT: LINESTRING(2 3,3 3,3 2,2 2) #points: 4 (2,3) (3,3) (3,2) (2,2) Press <RETURN> to close this window... */