与boost :: geometry :: union_结合使用的策略

Question

boost :: geometry :: union_（）带有一个可选的“ strategy”参数，该参数被描述为“满足Union_ Strategy概念的任何类型”。我有兴趣研究是否存在可以帮助我解决特定问题的现有策略。这是一些代码：

using point_t = boost::geometry::model::d2::point_xy<double>;
using polygon_t = boost::geometry::model::polygon<point_t>;
using mpolygon_t = boost::geometry::model::multi_polygon<polygon_t>;

polygon_t obstacle1{{{-2, 7},
                     {2, 7},
                     {2, 3},
                     {-2, 3},
                     {-2, 7}}};
mpolygon_t consolidated;
for (auto const& obstacle : obstacles) {
    if (boost::geometry::overlaps(obstacle, consolidated)) {
        mpolygon_t temp;
        boost::geometry::union_(obstacle, consolidated, temp);
        consolidated = std::move(temp);
    } else {
        consolidated.push_back(obstacle);
    }
}

polygon_t obstacle2{{{-2.8284271247461903, 5},
                     {0, 7.82842712474619},
                     {2.8284271247461903, 5},
                     {0, 2.1715728752538097},
                     {-2.8284271247461903, 5}}};

polygon_t obstacle3{{{0.75, 3.0},
                     {0.75, 2.4215728752538097},
                     {0.2, 2.4215728752538097},
                     {0.75, 3.0}}};
mpolygon_t obstacles{obstacle1, obstacle2, obstacle3};
mpolygon_t consolidated;
for (auto const& obstacle : obstacles) {
    if (boost::geometry::overlaps(obstacle, consolidated)) {
        mpolygon_t temp;
        boost::geometry::union_(obstacle, consolidated, temp);
        consolidated = std::move(temp);
    } else {
        consolidated.push_back(obstacle);
    }
}

我希望obstacle2和obstacle3的并集产生的顶点与obstacle2的适当边共线。我发现它们的距离大约是1e-7，这比我预期的要大得多（毕竟，基本坐标类型是double。

那么，有没有我可以提供的策略来减少我看到的错误？