Boost：：几何体：：与C++的交集

qyuhtwio 于 2023-03-05 发布在其他

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我是一个土木工程的博士生，最近开始用C++编程，基本上我对两个多边形的重叠或相交区域感兴趣，这两个多边形代表了两个土壤颗粒的投影。
我做了大量的搜索，我发现Boost几何是最适合我的解决方案。我也做了大量的搜索，我所面临的具体问题，但我无法解决我的问题。
问题是这样的，我使用的软件叫做PFC 3D（粒子流代码），我必须使用Microsoft Visual Studio 2010与这个软件交互，并编译DLL文件才能在PFC中运行它。
我的代码工作得很好，没有重叠区域。下面是代码：

// Includes for overlapping
#include <boost/geometry.hpp>
#include <boost/geometry/core/point_type.hpp>
#include <boost/geometry/geometries/point.hpp>
#include <boost/geometry/geometries/register/point.hpp>enter code here
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>
typedef boost::geometry::model::polygon<boost::geometry::model::d2::point_xy<double> > polygon;
polygon poly1, poly2;
poly1 {{0.0,  0.0}, {0.0, 1.0}, {1.0, 1.0}, {1.0,  0.0}, {0.05,  0.0}};
poly2 {{0.5, -0.5}, {0.5, 0.5}, {1.5, 0.5}, {1.5, -0.5},  {0.5, -0.5}};
std::deque<polygon> output;
boost::geometry::intersection(poly1, poly2, output);
double area = boost::geometry::area(output);

我得到的错误是在分配poly 1和poly 2坐标。希望你能在这方面提供帮助。谢谢！

c++

来源：https://stackoverflow.com/questions/46104647/boostgeometryintersection-with-c

2条答案

按热度按时间

kuarbcqp1#

identifier { }只有在identifier是类型名时才有效。
如果希望统一初始化，可以使用{ }作为构造函数参数列表的开头，并将每个参数环 Package 在一组额外的{ }中：

polygon poly1 { { { 0.0, 0.0 }, { 0.0, 1.0 }, { 1.0, 1.0 }, { 1.0, 0.0 }, { 0.05, 0.0 } }  };
polygon poly2 { { { 0.5, -0.5 }, { 0.5, 0.5 }, { 1.5, 0.5 }, { 1.5, -0.5 }, { 0.5, -0.5 } }  };

接下来，area不需要多多边形，所以编写一个循环：

double area = 0;
for (auto& p : output)
    area += boost::geometry::area(p);

我建议您查看dsv对输入的解析：

polygon poly1, poly2;
bg::read<bg::format_wkt>(poly1, "POLYGON((0 0,0 1,1 1,1 0,0.05 0,0 0))");
bg::read<bg::format_wkt>(poly2, "POLYGON((0.5 -0.5,0.5 0.5,1.5 0.5,1.5 -0.5,0.5 -0.5))");

实时演示：Live On Coliru

#include <iostream>
#include <boost/geometry.hpp>
#include <boost/geometry/io/io.hpp>
#include <boost/geometry/algorithms/area.hpp>
#include <boost/geometry/geometries/point.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>

namespace bg = boost::geometry;
namespace bgm = bg::model;
typedef bgm::polygon<bgm::d2::point_xy<double> > polygon;

int main() {
    polygon poly1, poly2;
    bg::read<bg::format_wkt>(poly1, "POLYGON((0 0,0 1,1 1,1 0,0.05 0,0 0))");
    bg::read<bg::format_wkt>(poly2, "POLYGON((0.5 -0.5,0.5 0.5,1.5 0.5,1.5 -0.5,0.5 -0.5))");

    std::cout << bg::wkt(poly1) << "\n";
    std::cout << bg::wkt(poly2) << "\n";
    std::deque<polygon> output;
    bg::intersection(poly1, poly2, output);

    double area = 0;
    for (auto& p : output)
        area += bg::area(p);
}

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wpx232ag2#

多边形中的点应该按顺时针排序。例如

#include <iostream>
#include <algorithm>
#include <boost/geometry.hpp>
#include <boost/geometry/io/io.hpp>
#include <boost/geometry/algorithms/area.hpp>
#include <boost/geometry/geometries/point.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/polygon.hpp>

namespace bg = boost::geometry;
namespace bgm = bg::model;
typedef bgm::d2::point_xy<double> point;
typedef bgm::polygon<point> polygon;

void testOverlap_anticlockwise();
void testOverlap_clockwise();

int main() {
    testOverlap_anticlockwise();
    testOverlap_clockwise();
}


void testOverlap_anticlockwise()
{
    polygon poly1;
    poly1.outer().push_back(point(15, 0.176766));
    poly1.outer().push_back(point(0.176767, 15));
    poly1.outer().push_back(point(-5, 16.6844));
    poly1.outer().push_back(point(-5, -5));
    poly1.outer().push_back(point(16.6844, -5));
    poly1.outer().push_back(point(15, 0.176766));

    polygon poly2;
    poly2.outer().push_back(point(15, 15));
    poly2.outer().push_back(point(0, 15));
    poly2.outer().push_back(point(0, 0));
    poly2.outer().push_back(point(15, 0));
    poly2.outer().push_back(point(15, 15));

    std::cout << bg::wkt(poly1) << "\n";
    std::cout << bg::wkt(poly2) << "\n";
    std::deque<polygon> output;
    bg::intersection(poly1, poly2, output);

    double area = 0;
    for (std::deque<polygon>::const_iterator it = output.begin(); it != output.end(); ++it) {
        area += bg::area(*it);
    }
    std::cout << area << std::endl;
}

void testOverlap_clockwise()
{
    polygon poly1;
    poly1.outer().push_back(point(15, 0.176766));
    poly1.outer().push_back(point(0.176767, 15));
    poly1.outer().push_back(point(-5, 16.6844));
    poly1.outer().push_back(point(-5, -5));
    poly1.outer().push_back(point(16.6844, -5));
    poly1.outer().push_back(point(15, 0.176766));
    std::reverse(poly1.outer().begin(), poly1.outer().end());

    polygon poly2;
    poly2.outer().push_back(point(15, 15));
    poly2.outer().push_back(point(0, 15));
    poly2.outer().push_back(point(0, 0));
    poly2.outer().push_back(point(15, 0));
    poly2.outer().push_back(point(15, 15));
    std::reverse(poly2.outer().begin(), poly2.outer().end());

    std::cout << bg::wkt(poly1) << "\n";
    std::cout << bg::wkt(poly2) << "\n";
    std::deque<polygon> output;
    bg::intersection(poly1, poly2, output);

    double area = 0;
    for (std::deque<polygon>::const_iterator it = output.begin(); it != output.end(); ++it) {
        area += bg::area(*it);
    }
    std::cout << area << std::endl;
}

结果为多边形（（15 0.176766，0.176767 15，-5 16. 6844，-5 -5，16.6844 -5，15 0.176766））多边形（（15 15，0 15，0 0，15 0，15 15））0
多边形（（15 0.17676，16.6844 -5，-5 -5，-5 16. 6844，0.176767 15，15 0.176766））多边形（（15 15，15 0，0 0，0 15，15 15））115.136

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Boost：：几何体：：与C++的交集

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