使用cgal計算兩個多邊形的交集區域

Question

給定兩個凸多邊形的頂點，使用cgal計算其交集區域的最簡單方法是什麼？

Answer 1

因爲您正在使用凸多邊形，所以不需要擔心孔。所以我能想到的最簡單的代碼基本上是構建多邊形，調用交集，遍歷交叉點和總區域：

#include <iostream> 
#include <CGAL/Simple_cartesian.h> 
#include <CGAL/Polygon_2.h> 
#include <CGAL/Polygon_with_holes_2.h> 
#include <CGAL/Boolean_set_operations_2.h> 
#include <CGAL/Polygon_2_algorithms.h> 


typedef CGAL::Simple_cartesian<double> K; 
typedef K::Point_2 Point; 
typedef CGAL::Polygon_2<K> Polygon_2; 
typedef CGAL::Polygon_with_holes_2<K> Polygon_with_holes_2; 
using std::cout; using std::endl; 


int main(){ 
    Point points[] = { Point(0,0), Point(1,0), Point(1,1), Point(0,1)}; 
    Point points2[] = { Point(0.5,0.5), Point(1.5,0.5), Point(1.5,1.5), Point(0.5,1.5)}; 
    Polygon_2 poly1(points, points+4); 
    Polygon_2 poly2(points2, points2+4); 
    //CGAL::General_polygon_with_holes_2<K> poly3; 
    std::list<Polygon_with_holes_2> polyI; 

    CGAL::intersection(poly1, poly2, std::back_inserter(polyI)); 

    double totalArea = 0; 
    typedef std::list<Polygon_with_holes_2>::iterator LIT; 
    for(LIT lit = polyI.begin(); lit!=polyI.end(); lit++){ 
    totalArea+=lit->outer_boundary().area(); 
    } 
    cout << "TotalArea::" << totalArea; 

}