我使用 GEOS 3.6.2 来计算两个多边形之间的交点。我能够构建我的多边形,但是当我尝试计算交叉点时,它不会起作用。
在调试模式下编译我的程序,我收到错误消息:
下级停止了因为它收到了来自操作的信号 系统
信号名称:SIGSEG
信号含义:分段错误
知道我哪里错了吗?
这是我的代码:
#include <geos/geom/Polygon.h>
#include <geos/geom/LinearRing.h>
#include <geos/geom/CoordinateSequenceFactory.h>
#include <geos/geom/GeometryFactory.h>
#include <geos/geom/Geometry.h>
#include <geos/operation/overlay/OverlayOp.h>
#include <iostream>
#include <array>
////////////////////////////////////////////////////////////////////////////////
geos::geom::Polygon* MakePoly(std::vector<std::vector<int>> const& polyCoords)
{
geos::geom::GeometryFactory* factory = geos::geom::GeometryFactory::create().get();
geos::geom::CoordinateSequence* temp = factory->getCoordinateSequenceFactory()->create((std::size_t) 0, 0);
std::vector<std::vector<int>>::const_iterator it_x = polyCoords.begin();
int size = it_x->size();
for (int i=0; i<size; i++)
{
temp->add(geos::geom::Coordinate(polyCoords[0][i], polyCoords[1][i]));
}
geos::geom::LinearRing *shell=factory->createLinearRing(temp);
//NULL in this case could instead be a collection of one or more holes
//in the interior of the polygon
return factory->createPolygon(shell,NULL);
}
////////////////////////////////////////////////////////////////////////////////
int main()
{
// Create geometry.
std::vector<std::vector<int>> polyCoords1 = {
{1, 1, 2, 2, 1, 1, 4, 5, 4, 1},
{1, 2, 2, 4, 4, 5, 5, 3, 1, 1}
};
geos::geom::Polygon* poly1 = MakePoly(polyCoords1);
std::vector<std::vector<int>> polyCoords2 = {
{4, 4, 6, 6, 4},
{1, 5, 5, 1, 1}
};
geos::geom::Polygon* poly2 = MakePoly(polyCoords2);
// Actually perform the operation.
geos::operation::overlay::OverlayOp intersection(poly1, poly2);
// Extracting the geometry of the intersection (position of the error).
geos::geom::Geometry* intersectionGeo = intersection.getResultGeometry( geos::operation::overlay::OverlayOp::OpCode::opINTERSECTION );
std::cout<<intersectionGeo->getArea()<<std::endl;
}
答案 0 :(得分:0)
您的代码中的问题是获取GeometryFactory指针。
geos :: geom :: GeometryFactory :: create()返回一个智能指针(std :: unique_ptr),因此在此行之后:
geos::geom::GeometryFactory* factory = geos::geom::GeometryFactory::create().get();
由create返回的unique_ptr被处置。
使用以下方法更改该行:
geos::geom::GeometryFactory::Ptr factory = geos::geom::GeometryFactory::create();
代码有效。