C++的GEOS库实现几何计算，多个面和一条线相交后得到多条线段的例子。

在vcpkg包管理工具的环境下使用VisualStudio，vcpkg确认已安装gdal:x64-windows库。

#include 
#include 
#include 
#include 
#include 
#include 

using namespace std;
static void geos_msg_handler(const char* fmt, ...){
    va_list ap;
    va_start(ap, fmt);
    vprintf(fmt, ap);
    va_end(ap);
}

double getPointX(double* dxdy) {
    return *dxdy;
}
double getPointY(double* dxdy) {
    return *(dxdy + 1);
}
double* getPointXY(GEOSGeometry* pt, GEOSWKTWriter* writer) {
    char* wkt = GEOSWKTWriter_write(writer, pt);
    //在这里，点对应的wkt字符串的小数部分固定是18位字符
    char* x = new char[18];
    char* y = new char[18];
    int state = 0;
    int count = 0;
    //第7位字符到第43位字符都是数字部分
    for (int i = 7; i < 44; i++) {
        if (state == 0) {
            *(x + count) = wkt[i];
            count++;
        }
        else {
            *(y + count) = wkt[i];
            count++;
        }
        if (wkt[i] == ' ') {
            count = 0;
            state = 1;
        }
    }
    double* dxdy = new double[2];
    *dxdy = atof(x);
    *(dxdy + 1) = atof(y);
    return dxdy;
}


int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    initGEOS(geos_msg_handler, geos_msg_handler);
    GEOSWKTReader* reader = GEOSWKTReader_create();
    GEOSGeometry* line_geo = GEOSWKTReader_read(reader, "LINESTRING(0.512114 0.5,1 1,1.5 1.5,2.5 0.5,4.5 1.5)");
    //GEOSGeometry* polygon_geo = GEOSWKTReader_read(reader, "MULTIPOLYGON(((0 0,1 0,1 1,0 1,0 0)),((2 0,3 0,3 1,2 1,2 0)),((4 1,5 1,5 2,4 2,4 1)))");
    GEOSGeometry* polygon_geo = GEOSWKTReader_read(reader, "MULTIPOLYGON(((0 0,1 0,1 1,0 1,0 0)),((2 0,3 0,3 1,2 1,2 0)),((4 1,5 1,5 2,4 2,4 1)))");
    GEOSGeometry* multi_line = GEOSIntersection(line_geo, polygon_geo);
    GEOSWKTWriter* writer = GEOSWKTWriter_create();
    int line_num = GEOSGetNumGeometries(multi_line);//线条的个数.

    for (int i = 0; i < line_num; i++) {
        const GEOSGeometry* line = GEOSGetGeometryN(multi_line, i);
        int point_num = GEOSGetNumCoordinates(line);
        cout << "第"<
            GEOSGeometry* pt = GEOSGeomGetPointN(line, j);
            double* xy = getPointXY(pt, writer);
            cout << "x:" << xy[0] << "t" << "y:" << xy[1] << endl;
        }
    }

    finishGEOS();

    return 0;
}

运行效果：