[experimental] update test-demo with version with lambdas

test/robustness/within/Jamfile

@@ -0,0 +1,17 @@
+# Boost.Geometry (aka GGL, Generic Geometry Library)
+# Robustness Test - convex_hull
+#
+# Copyright (c) 2012 Barend Gehrels, Amsterdam, the Netherlands.
+
+# Use, modification and distribution is subject to the Boost Software License,
+# Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+
+project partition_within
+    : requirements
+        <include>.
+        <link>static
+    ;
+
+exe partition_within : partition_within.cpp ;

test/robustness/within/partition_within.cpp

@@ -17,6 +17,8 @@
 # include <boost/geometry/io/svg/svg_mapper.hpp>
 #endif
 
+#include "quadtree_partition.hpp"
+
 #include <chrono>
 #include <random>
 #include <fstream>
@@ -43,112 +45,41 @@ struct ring_item
 
 BOOST_GEOMETRY_REGISTER_POINT_2D(point_item, double, cs::cartesian, x, y)
 
-
-struct expand_for_point
-{
-    template <typename Box, typename InputItem>
-    static inline void apply(Box& total, InputItem const& item)
-    {
-        bg::expand(total, item);
-    }
-};
-
-struct overlaps_point
+#if defined(TEST_WITH_SVG)
+template <typename Points, typename Rings, typename Box, typename Boxes>
+void create_svg(std::size_t size, Points const& points, Rings const& rings, std::size_t index, 
+            Box const& box, int level,
+            Boxes& boxes)
 {
-    template <typename Box, typename InputItem>
-    static inline bool apply(Box const& box, InputItem const& item)
-    {
-        return ! bg::disjoint(item, box);
-    }
-};
+    std::ostringstream filename;
+    filename << "partition_demo_" << std::setfill('0') << std::setw(3) << index << "_" << level << ".svg";
+    std::ofstream svg(filename.str());
 
+    bg::svg_mapper<point_item> mapper(svg, 800, 800);
 
-struct expand_for_ring
-{
-    template <typename Box, typename InputItem>
-    static inline void apply(Box& total, InputItem const& item)
     {
-        bg::expand(total, item.box);
+        point_item p;
+        p.x = -1; p.y = -1; mapper.add(p);
+        p.x = size + 1; p.y = size + 1; mapper.add(p);
     }
-};
 
-struct overlaps_ring
-{
-    template <typename Box, typename InputItem>
-    static inline bool apply(Box const& box, InputItem const& item)
+    for (auto const& item : rings)
     {
-        typename bg::strategy::disjoint::services::default_strategy
-            <
-                Box, Box
-            >::type strategy;
-
-        return ! bg::detail::disjoint::disjoint_box_box(box, item.box, strategy);
+        mapper.map(item.ring, "opacity:0.6;fill:rgb(0,255,0);stroke:rgb(0,0,0);stroke-width:0.1");
     }
-};
-
-struct point_in_ring_visitor
-{
-    std::size_t count = 0;
-
-    template <typename Point, typename BoxItem>
-    inline bool apply(Point const& point, BoxItem const& ring_item)
+    for (auto const& point : points)
     {
-        if (bg::within(point, ring_item.ring))
-        {
-            count++;
-        }
-        return true;
+        mapper.map(point, "fill:rgb(0,0,255);stroke:rgb(0,0,100);stroke-width:0.1", 3);
     }
-};
 
-#if defined(TEST_WITH_SVG)
-template <typename Box, typename Points, typename Rings>
-struct svg_visitor
-{
-    std::vector<Box> boxes;
-    Points const& m_points;
-    Rings const& m_rings;
-    std::size_t m_size = 0;
-    std::size_t m_index = 0;
-
-    svg_visitor(std::size_t size, Points const& points, Rings const& rings)
-        : m_points(points)
-        , m_rings(rings)
-        , m_size(size)
-    {}
-
-    inline void apply(Box const& box, int level)
+    for (auto const& b : boxes)
     {
-        std::ostringstream filename;
-        filename << "partition_demo_" << std::setfill('0') << std::setw(3) << m_index++ << "_" << level << ".svg";
-        std::ofstream svg(filename.str());
-
-        bg::svg_mapper<point_item> mapper(svg, 800, 800);
-
-        {
-            point_item p;
-            p.x = -1; p.y = -1; mapper.add(p);
-            p.x = m_size + 1; p.y = m_size + 1; mapper.add(p);
-        }
-
-        for (auto const& item : m_rings)
-        {
-            mapper.map(item.ring, "opacity:0.6;fill:rgb(0,255,0);stroke:rgb(0,0,0);stroke-width:0.1");
-        }
-        for (auto const& point : m_points)
-        {
-            mapper.map(point, "fill:rgb(0,0,255);stroke:rgb(0,0,100);stroke-width:0.1", 3);
-        }
-
-        for (auto const& b : boxes)
-        {
-            mapper.map(b, "fill:none;stroke-width:2;stroke:rgb(64,64,64);");
-        }
-        mapper.map(box, "fill:none;stroke-width:4;stroke:rgb(255, 0, 0);");
-
-        boxes.push_back(box);
+        mapper.map(b, "fill:none;stroke-width:2;stroke:rgb(64,64,64);");
     }
-};
+    mapper.map(box, "fill:none;stroke-width:4;stroke:rgb(255, 0, 0);");
+
+    boxes.push_back(box);
+}
 #endif
 
 
@@ -311,27 +242,46 @@ void call_within(std::size_t size, std::size_t count)
         return elapsed;
     };
 
-    point_in_ring_visitor count_visitor;
-    {
 #if defined(TEST_WITH_SVG)
-
-        using partition_box_visitor_type = svg_visitor<box_type, std::vector<point_item>, std::vector<ring_item<ring_type>>>;
-        partition_box_visitor_type partition_box_visitor(size, points, rings);
-#else
-        using partition_box_visitor_type = bg::detail::partition::visit_no_policy;
-        partition_box_visitor_type partition_box_visitor;
+    std::size_t index = 0;
+    std::vector<box_type> boxes;
+    auto box_visitor = [&](auto const& box, int level)
+        {
+            create_svg(size, points, rings, index++, box, level, boxes);
+        };
+#else            
+    auto box_visitor = [&](auto const& , int ) {};
 #endif
 
+    std::size_t quadtree_count = 0;
+    {
         auto const start = std::chrono::steady_clock::now();
 
-        bg::partition
-            <
-                box_type,
-                bg::detail::partition::include_all_policy,
-                bg::detail::partition::include_all_policy
-            >::apply(points, rings, count_visitor, expand_for_point(), overlaps_point(),
-                    expand_for_ring(), overlaps_ring(), 16, partition_box_visitor);
-        report("Partition", start, count_visitor.count);
+        bg::experimental::quadtree_partition<box_type>(points, 
+            rings, 
+            [](auto& box, auto const& point) { bg::expand(box, point); },
+            [](auto const& box, auto const& point) { return ! bg::disjoint(point, box); },
+            [](auto& box, auto const& item) { bg::expand(box, item.box); },
+            [](auto const& box, auto const& item) 
+            {
+                typename bg::strategy::disjoint::services::default_strategy
+                    <
+                        box_type, box_type
+                    >::type strategy;
+                return ! bg::detail::disjoint::disjoint_box_box(box, item.box, strategy);
+            },
+            [&quadtree_count](auto const& p, auto const& ri)
+            {
+                if (bg::within(p, ri.ring))
+                {
+                    quadtree_count++;
+                }
+                return true;
+            },
+            box_visitor
+            );
+
+        report("Partition", start, quadtree_count);
     }
 
     {
@@ -350,7 +300,7 @@ void call_within(std::size_t size, std::size_t count)
         }
         report("Quadratic loop", start, count);
 
-        if (count != count_visitor.count)
+        if (count != quadtree_count)
         {
             std::cerr << "ERROR: counts are not equal" << std::endl;
         }

test/robustness/within/quadtree_partition.hpp

@@ -0,0 +1,98 @@
+// Boost.Geometry (aka GGL, Generic Geometry Library)
+
+// Copyright (c) 2023 Barend Gehrels, Amsterdam, the Netherlands.
+// Use, modification and distribution is subject to the Boost Software License,
+// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+#ifndef BOOST_GEOMETRY_EXPERIMENTAL_QUADTREE_PARTITION_HPP
+#define BOOST_GEOMETRY_EXPERIMENTAL_QUADTREE_PARTITION_HPP
+
+#include <boost/range.hpp>
+#include <boost/geometry/algorithms/detail/partition.hpp>
+
+#include <functional>
+
+namespace boost { namespace geometry
+{
+
+namespace experimental
+{
+
+template <typename F>
+struct adapt_partition_visitor
+{
+    F m_f;
+
+    explicit adapt_partition_visitor(F&& f)
+        : m_f(std::move(f))
+    {}
+
+    template <typename ...Ts>
+    decltype(auto) apply(Ts&& ...is) const
+    {
+        return m_f(std::forward<Ts>(is)...);
+    }
+};    
+
+template
+<
+    typename BoxType,
+    typename ForwardRange1,
+    typename ForwardRange2
+>
+bool quadtree_partition(ForwardRange1 const& forward_range1,
+                        ForwardRange2 const& forward_range2,
+                        const std::function
+                            <
+                                void(BoxType&, 
+                                     typename boost::range_value<ForwardRange1>::type const&)
+                            >& expand_policy1,
+                        const std::function
+                            <
+                                bool(BoxType const&, 
+                                     typename boost::range_value<ForwardRange1>::type const&)
+                            >& overlaps_policy1,
+                        const std::function
+                            <
+                                void(BoxType&, 
+                                     typename boost::range_value<ForwardRange2>::type const&)
+                            >& expand_policy2,
+                        const std::function
+                            <
+                                bool(BoxType const&, 
+                                     typename boost::range_value<ForwardRange2>::type const&)
+                            >& overlaps_policy2,
+                        const std::function
+                            <
+                                bool(typename boost::range_value<ForwardRange1>::type const&, 
+                                     typename boost::range_value<ForwardRange2>::type const&)
+                            >& visitor,
+                        const std::function
+                            <
+                                void(BoxType const&, int level)
+                            >& box_visitor = [](auto const&, int) {})
+{
+    adapt_partition_visitor<decltype(visitor)> av(visitor);
+    adapt_partition_visitor<decltype(expand_policy1)> aev1(expand_policy1);
+    adapt_partition_visitor<decltype(expand_policy2)> aev2(expand_policy2);
+    adapt_partition_visitor<decltype(overlaps_policy1)> aov1(overlaps_policy1);
+    adapt_partition_visitor<decltype(overlaps_policy2)> aov2(overlaps_policy2);
+    adapt_partition_visitor<decltype(box_visitor)> apbv(box_visitor);
+
+    // TODO: the "16" could be part of an optional options structure
+    // The all_policies (it is never run in a different way) could be
+    // a compiletime part of that options structure as well.
+    return partition
+        <
+            BoxType,
+            detail::partition::include_all_policy,
+            detail::partition::include_all_policy
+        >::apply(forward_range1, forward_range2, av, 
+                 aev1, aov1,
+                 aev2, aov2, 16, apbv);    
+}                            
+
+}}} // namespace boost::geometry::experimental
+
+#endif // BOOST_GEOMETRY_EXPERIMENTAL_QUADTREE_PARTITION_HPP