我想找到在rtree中索引的所有元素，这些元素与带有孔的多边形的外环相交，但是使用Boost C ++库并不完全在任何孔内。
我知道如何使元素与外环相交：
// Constructing the exterior ring polygon
Boost2dRing p;
for (int i = 0; i < numPunts; i++)
{
x = Punts.at(i).x;
y = Punts.at(i).y;
p.push_back(Boost2dPoint(x, y));
}
// Getting the intersecting elements with that polygon
m_RTree.query(bgi::intersects(p), std::back_inserter(res));
...
// Constructing the polygon for the inner ring (hole)
Boost2dRing p;
for (int i = 0; i < numPuntsHole; i++)
{
x = PuntsHole.at(i).x;
y = PuntsHole.at(i).y;
pHole.push_back(Boost2dPoint(x, y));
}
// Now I try to get the elements inside completely this polygon but I get a compilation error
m_RTree.query(bgi::within(pHole), std::back_inserter(res));
错误信息：
错误C2664：'int boost :: mpl :: assertion_failed（boost :: mpl :: assert :: type）'：无法从'boost :: mpl :: fail ***********转换参数1 *（__ cdecl boost :: geometry :: strategy :: within :: services :: default_strategy :: NOT_IMPLEMENTED_FOR_THESE_TYPES :: * ***********）（boost :: mpl :: assert _ :: types）' 'boost :: mpl :: assert :: type'1> with 1> [1> Geometry1 = Boost2dBox，1> Geometry2 = Boost2dRing，1> GeometryContained = Boost2dBox，1> GeometryContaining = Boost2dRing 1>]注意：没有构造函数可以采用源类型，或者构造函数重载决策是模糊的
任何暗示实现这一目标？
对于您选择的几何操作数，未实现内部谓词。
但是，你可以用更少的工作做你想做的事。假设你有戒指，例如：
Boost2dRing exterior, interior;
bg::read_wkt("POLYGON((0.1 0.1,0.1 0.5,0.5 0.5,0.5 0.1,0.1 0.1))", exterior);
bg::read_wkt("POLYGON((0.2 0.2,0.2 0.4,0.4 0.4,0.4 0.2,0.2 0.2))", interior);
现在，Boost几何有一个Polygon的概念，它是一个外环和（多个）内环：
多边形是多边形是由一个外部边界和零个或多个内部边界定义的平面（OGC Simple Feature Specification）
所以，让我们改用它：
bg::reverse(interior);
Boost2dPolygon polygon;
polygon.outer() = exterior;
polygon.inners().push_back(interior);
注意，内环的方向是反转的。
或者，实际上，直接使用构造函数：
Boost2dPolygon polygon({exterior, interior});
或者，甚至立即从WKT阅读：
bg::read_wkt("POLYGON((0.1 0.1,0.1 0.5,0.5 0.5,0.5 0.1,0.1 0.1) (0.2 0.2,0.4 0.2,0.4 0.4,0.2 0.4,0.2 0.2))", polygon);
现在您只需一次查询即可：
std::vector<RTree::value_type> res;
m_RTree.query(bgi::intersects(polygon), std::back_inserter(res));
鉴于以下sample()树内容：
using RTree = bgi::rtree<std::pair<Boost2dBox, std::string>, bgi::rstar<16> >;
RTree sample() {
RTree tree;
std::pair<std::string, std::string> items[] = {
{ "BOX(0.2 0.2,0.2 0.4,0.4 0.4,0.4 0.2,0.2 0.2)", "ok" },
{ "BOX(0.28 0.28,0.28 0.32,0.32 0.32,0.32 0.28,0.28 0.28)", "within gap" },
{ "BOX(0.28 0.28,0.28 0.32,0.36 0.32,0.36 0.28,0.28 0.28)", "small overlap" },
{ "BOX(2 2,2 4,4 4,4 2,2 2)", "outside exterior" },
};
for (auto& item : items) {
Boost2dBox box;
bg::read_wkt(item.first, box);
checks("box", box);
tree.insert({box, item.second});
}
return tree;
}
我们可以手动测试：
RTree const m_RTree = sample();
std::cout << "Sample tree:\n";
for (auto& value : m_RTree) {
std::cout << " - " << std::quoted(value.second) << ": " << bg::wkt(value.first) << "\n";
Boost2dMultiPolygon mp;
if (bg::intersection(polygon, value.first, mp))
std::cout << " (intersection is " << bg::wkt(mp) << ")\n";
}
哪个打印
Sample tree:
- "ok": POLYGON((0.2 0.2,0.2 0.4,0.4 0.4,0.4 0.2,0.2 0.2))
(intersection is MULTIPOLYGON(((0.2 0.2,0.2 0.4,0.4 0.4,0.4 0.2,0.2 0.2),(0.25 0.25,0.35 0.25,0.35 0.35,0.25 0.35,0.25 0.25))))
- "within gap": POLYGON((0.28 0.28,0.28 0.32,0.32 0.32,0.32 0.28,0.28 0.28))
(intersection is MULTIPOLYGON())
- "small overlap": POLYGON((0.28 0.28,0.28 0.32,0.36 0.32,0.36 0.28,0.28 0.28))
(intersection is MULTIPOLYGON(((0.35 0.32,0.36 0.32,0.36 0.28,0.35 0.28,0.35 0.32))))
- "outside exterior": POLYGON((2 2,2 4,4 4,4 2,2 2))
(intersection is MULTIPOLYGON())
并验证与树查询比较的结果：
m_RTree.query(bgi::intersects(polygon), std::back_inserter(matches));
std::cout << "Intersecting with: ";
for (auto& match : matches) std::cout << " " << std::quoted(match.second) << " ";
哪个印刷品：
Intersecting with: "ok" "small overlap"
看到所有Live On Coliru
#include <boost/geometry.hpp>
#include <boost/geometry/geometries/point_xy.hpp>
#include <boost/geometry/geometries/multi_polygon.hpp>
#include <boost/geometry/geometries/linestring.hpp>
#include <boost/geometry/geometries/multi_polygon.hpp>
#include <boost/geometry/core/cs.hpp>
#include <boost/geometry/arithmetic/arithmetic.hpp>
#include <boost/geometry/algorithms/within.hpp>
#include <boost/geometry/algorithms/intersects.hpp>
#include <boost/geometry/algorithms/envelope.hpp>
#include <boost/geometry/algorithms/intersection.hpp>
#include <boost/geometry/index/rtree.hpp>
#include <boost/geometry/index/predicates.hpp>
#include <boost/geometry/index/adaptors/query.hpp>
#include <boost/geometry/io/io.hpp>
#include <iostream>
#include <fstream>
namespace bg = boost::geometry;
namespace bgi = boost::geometry::index;
using Boost2dPoint = bg::model::d2::point_xy<double>;
using Boost2dRing = bg::model::ring<Boost2dPoint>;
using Boost2dPolygon = bg::model::polygon<Boost2dPoint>;
using Boost2dMultiPolygon = bg::model::multi_polygon<Boost2dPolygon>;
using Boost2dBox = bg::model::box<Boost2dPoint>;
template <typename G> void checks(std::string name, G& geom) {
std::cout << name << ": " << bg::wkt(geom) << "\n";
std::string reason;
if (!bg::is_valid(geom, reason)) {
std::cout << name << ": " << reason << "\n";
bg::correct(geom);
std::cout << bg::wkt(geom) << "\n";
if (!bg::is_valid(geom, reason)) {
std::cout << name << " corrected: " << reason << "\n";
}
}
}
using RTree = bgi::rtree<std::pair<Boost2dBox, std::string>, bgi::rstar<16> >;
RTree sample() {
RTree tree;
std::pair<std::string, std::string> items[] = {
{ "BOX(0.2 0.2,0.2 0.4,0.4 0.4,0.4 0.2,0.2 0.2)", "ok" },
{ "BOX(0.28 0.28,0.28 0.32,0.32 0.32,0.32 0.28,0.28 0.28)", "within gap" },
{ "BOX(0.28 0.28,0.28 0.32,0.36 0.32,0.36 0.28,0.28 0.28)", "small overlap" },
{ "BOX(2 2,2 4,4 4,4 2,2 2)", "outside exterior" },
};
for (auto& item : items) {
Boost2dBox box;
bg::read_wkt(item.first, box);
checks("box", box);
tree.insert({box, item.second});
}
return tree;
}
int main() {
Boost2dPolygon polygon;
bg::read_wkt("POLYGON((0.1 0.1,0.1 0.5,0.5 0.5,0.5 0.1,0.1 0.1) (0.25 0.25,0.35 0.25,0.35 0.35,0.25 0.35,0.25 0.25))", polygon);
checks("polygon", polygon);
RTree const m_RTree = sample();
std::cout << "Sample tree:\n";
for (auto& value : m_RTree) {
std::cout << " - " << std::quoted(value.second) << ": " << bg::wkt(value.first) << "\n";
Boost2dMultiPolygon mp;
if (bg::intersection(polygon, value.first, mp))
std::cout << " (intersection is " << bg::wkt(mp) << ")\n";
}
std::cout << "\n";
std::vector<RTree::value_type> matches;
m_RTree.query(bgi::intersects(polygon), std::back_inserter(matches));
std::cout << "Intersecting with: ";
for (auto& match : matches) std::cout << " " << std::quoted(match.second) << " ";
std::cout << "\n";
}