箱升压RTREE给出了段相交错误 [英] boost rtree of box gives wrong intersection with segment

问题描述

升压RTREE给出了一些交叉口段查询交集错误的结果。
在这种情况下，边框在y = 0的y平面10×10平方。我与一个Z-对齐线从查询（2,1，0）到（2,1，10）。有趣的是，如果我用一个框查询，而不是一个段，那么它将按预期工作。这种行为也是present当箱子不是平面，只要将分一角（0，-5，0），它仍然发生。

Boost rtree gives wrong intersection result for some intersection with segment queries. In this case the bounding box is a y-planar 10x10 square at y=0. I'm querying with a z-aligned line from (2, 1, 0) to (2, 1, 10). What's interesting is that if I use a box for query instead of a segment then it works as expected. This behavior is also present when the box is not planar, just move the min corner to (0, -5, 0) and it still happens.

我使用这个错误或者是在提升一个bug？

Am I using this wrong or is it a bug in boost?

编辑：曾尝试对升压1.56和1.59

have tried this on Boost 1.56 and 1.59.

#include <vector>
#include "gtest/gtest.h"
#include "gmock/gmock.h"
#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point.hpp>
#include <boost/geometry/geometries/box.hpp>
#include <boost/geometry/geometries/segment.hpp>
#include <boost/geometry/index/rtree.hpp>
#include <vector>
#include <iterator>
#include <memory>

namespace bg = boost::geometry;
namespace bgi = boost::geometry::index;
typedef bg::model::point<double, 3, bg::cs::cartesian> point_def;
typedef bg::model::box<point_def> box;
typedef bg::model::segment<point_def> segment;
typedef std::pair<box, size_t> tri_box;
typedef bgi::rtree< tri_box, bgi::linear<8>> tree_type;

using namespace std;

TEST(boost_rtree, cant_intersect_box_with_segment) {
  vector<tri_box> buff(1);
  buff[0].first = box{point_def{0, 0, 0}, point_def{10, 0, 10}};
  buff[0].second = 1;
  tree_type tree(buff);

  segment query{point_def{2, 1, 0}, point_def{2, 1, 10}};
//  box query{point_def{2, 1, 0}, point_def{2, 1, 10}};
  vector<tri_box> out;

  size_t count = tree.query(bgi::intersects(query), back_inserter(out));

  ASSERT_EQ(0, count); // fails here
  ASSERT_EQ(0, out.size());
}

编辑：问题正在采取行动，扩大邮件列表：lists.boost.org/geometry/2015/09/3472.php

issue is being moved to boost mailing list: lists.boost.org/geometry/2015/09/3472.php

推荐答案

由于不太可能，因为它看来，这在我看来是一个错误。

As unlikely as it seems, this appears to me to be a bug.

这甚至编译这样做的第一个版本是1.56提升。所有previous版本失败，

The first version that even compiles this is Boost 1.56. All previous versions fail with

BOOST_MPL_ASSERT_MSG
    (
        false, NOT_OR_NOT_YET_IMPLEMENTED_FOR_THIS_GEOMETRY_TYPE
        , (types<Geometry>)
    );

不过，即使code编译，它似乎并不正确......：在相交电话构成了这一查询predicate本身返回假阳性看来。

But, even though the code is compiled, it does not seem to be correct...: the intersects call that underlies the query predicate itself returns "false positive" it seems.

大大简化： <大骨节病> 住在Coliru

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/box.hpp>
#include <boost/geometry/geometries/segment.hpp>

namespace bg  = boost::geometry;

typedef bg::model::point<int, 3, bg::cs::cartesian> point;
typedef bg::model::box<point>     box;
typedef bg::model::segment<point> segment;

int main() {
    box y0rect = box{point{0, 0, 0}, point{10, 0, 10}};
    segment seg{point{2, 1, 0}, point{2, 1, 10}};

    bg::correct(y0rect);
    bg::correct(seg);
    assert(!bg::intersects(seg, y0rect));
}

更新

有趣的是，它似乎正常工作的有时的作为2D。我不知道结果不是简单地不确定...

Interestingly, it seems to work correctly sometimes for 2d. I'm not sure the outcome isn't simply undefined...

<大骨节病> 住在Coliru

#include <boost/geometry.hpp>
#include <boost/geometry/geometries/box.hpp>
#include <boost/geometry/geometries/segment.hpp>

namespace bg  = boost::geometry;

typedef bg::model::point<int, 4, bg::cs::cartesian> point;
typedef bg::model::box<point>     box;
typedef bg::model::segment<point> segment;

int main() {
    box y0rect = box{point{0, 0}, point{10, 10}};
    bg::correct(y0rect);

    {
        segment seg{point{12, 0}, point{20, 10}};
        bg::correct(seg);
        assert(!bg::intersects(seg, y0rect));
    }
    {
        segment seg{point{2, 0}, point{8, 6}};
        bg::correct(seg);
        assert(bg::intersects(seg, y0rect));
    }
    {
        segment seg{point{2, 0}, point{18, 6}};
        bg::correct(seg);
        assert(bg::intersects(seg, y0rect)); // OOPS BREAKS?
    }
}

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