Boost C++ Libraries

Checks if a geometry is simple.

Synopsis

template<typename Geometry, typename Strategy>
bool is_simple(Geometry const & geometry, Strategy const & strategy)

Parameters

Returns

Returns true if the geometry is simple

Header

Either

#include <boost/geometry.hpp>

Or

#include <boost/geometry/algorithms/is_simple.hpp>

Conformance

The function is_simple implements function IsSimple from the OGC Simple Feature Specification.

Supported geometries

Complexity

Constant-time for points, segments and boxes

Linear for rings, polygons and multi-polygons

Linearithmic for multi-points, linestrings and multi-linestrings

Example

Checks whether a geometry is simple

#include <iostream>

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/linestring.hpp>
#include <boost/geometry/geometries/multi_linestring.hpp>


int main()
{
    typedef boost::geometry::model::d2::point_xy<double> point_type;
    typedef boost::geometry::model::linestring<point_type> linestring_type;
    typedef boost::geometry::model::multi_linestring<linestring_type> multi_linestring_type;

    multi_linestring_type multi_linestring;
    boost::geometry::read_wkt("MULTILINESTRING((0 0,0 10,10 10,10 0,0 0),(10 10,20 20))", multi_linestring);

    std::cout << "is simple? "
              << (boost::geometry::is_simple(multi_linestring) ? "yes" : "no")
              << std::endl;

    return 0;
}

Output:

is simple? no

See also