diff --git a/example/ml01_multipolygon_simplify.cpp b/example/ml01_multipolygon_simplify.cpp new file mode 100644 index 000000000..d423c6983 --- /dev/null +++ b/example/ml01_multipolygon_simplify.cpp @@ -0,0 +1,67 @@ +// Boost.Geometry (aka GGL, Generic Geometry Library) + +// Copyright (c) 2009-2011 Mateusz Loskot, London, UK. + +// 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) +// +// Multipolygon DP simplification example from the mailing list discussion +// about the DP algorithm issue: +// http://lists.osgeo.org/pipermail/ggl/2011-September/001533.html + +#include +#include +#include +#include +#include +#include + +int main() +{ + typedef boost::geometry::model::d2::point_xy point_xy; + typedef boost::geometry::model::polygon polygon; + typedef boost::geometry::model::ring ring; + typedef boost::geometry::model::multi_polygon multi_polygon; + + multi_polygon original_1; + multi_polygon simplified_1; + + // Values between 0..1 and simplified with 1/2048 + boost::geometry::read_wkt("MULTIPOLYGON(((0.561648 1,1 1,1 0,0.468083 0,0.52758 0.00800554,0.599683 0.0280924,0.601611 0.265374,0.622693 0.316765,0.69507 0.357497,0.695623 0.429711,0.655111 0.502298,0.696467 0.543147,0.840712 0.593546,0.882583 0.66546,0.852357 0.748213,0.84264 0.789567,0.832667 0.841202,0.832667 0.841202,0.740538 0.873004,0.617349 0.905045,0.566576 0.977697,0.561648 1)),((0 0.801979,0.0308575 0.786234,0.0705513 0.631135,0.141616 0.527248,0.233985 0.505872,0.264777 0.526263,0.336631 0.505009,0.356603 0.422321,0.355803 0.350038,0.375252 0.205364,0.415206 0.0709182,0.45479 0,0 0,0 0,0 0.801979)))", original_1); + + std::cout << "Original: \n" << boost::geometry::num_points(original_1) << " points.\n\n"; + + boost::geometry::simplify(original_1, simplified_1, 1.0 / 2048.0); + + std::cout << "Polygon with values 0..1 and simplified with 1.0 / 2048.0 \n" + << "Result: \n" << boost::geometry::wkt(simplified_1) << "\n" << boost::geometry::num_points(simplified_1) << " points.\n\n"; + + // Multiply every points from original_1 by 2047 + multi_polygon original_2(original_1); + BOOST_FOREACH(polygon& p, original_2) + { + BOOST_FOREACH(point_xy& pt, p.outer()) + { + pt.x(pt.x() * 2047.0); + pt.y(pt.y() * 2047.0); + } + + BOOST_FOREACH(ring& r, p.inners()) + { + BOOST_FOREACH(point_xy& pt, r) + { + pt.x(pt.x() * 2047.0); + pt.y(pt.y() * 2047.0); + } + } + } + + multi_polygon simplified_2; + boost::geometry::simplify(original_2, simplified_2, 1.0); + std::cout << "Same values but multiplied by 2047.0 and simplified with 1.0\n" + << "Result: \n" << boost::geometry::wkt(simplified_2) << "\n" << boost::geometry::num_points(simplified_2) << " points.\n"; + + return 0; +} + diff --git a/example/ml01_multipolygon_simplify.vcproj b/example/ml01_multipolygon_simplify.vcproj new file mode 100644 index 000000000..fe5492da9 --- /dev/null +++ b/example/ml01_multipolygon_simplify.vcproj @@ -0,0 +1,171 @@ + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +