From 973aec43ea54bbf95b64fbcb636403401d1ca60e Mon Sep 17 00:00:00 2001
From: Rutger Broekhoff
Date: Fri, 28 Aug 2026 18:03:05 +0200
Subject: Import from e4b104792206ee7ea64bf39c6b7d2c0c230f9d14

---
 server/src/geo.cppm | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 server/src/geo.cppm

(limited to 'server/src/geo.cppm')

diff --git a/server/src/geo.cppm b/server/src/geo.cppm
new file mode 100644
index 0000000..5cdbdd9
--- /dev/null
+++ b/server/src/geo.cppm
@@ -0,0 +1,40 @@
+module;
+
+#include <boost/geometry.hpp>
+
+export module routemon:geo;
+
+export namespace bgeo = boost::geometry;
+
+export namespace routemon::geo {
+
+  using point = bgeo::model::point<double, 2, bgeo::cs::spherical_equatorial<bgeo::degree>>;
+  using linestring = bgeo::model::linestring<point>;
+  using box = bgeo::model::box<point>;
+  using stype = bgeo::srs::spheroid<double>;
+  using vincenty_strategy = bgeo::strategy::distance::vincenty<stype>;
+
+  auto split_linestring_with_overlap_segments(linestring const& ls, double max_split_distance_m, std::vector<linestring>& append_to) -> void {
+    if (bgeo::is_empty(ls))
+      return;
+
+    auto current_ls = linestring{};
+    auto current_ls_length = 0.0;
+    auto previous = std::optional<point>{};
+    bgeo::for_each_point(ls, [&](point p) -> void {
+      bgeo::append(current_ls, p);
+      if (previous) {
+        auto d = bgeo::distance(*previous, p, vincenty_strategy());
+        current_ls_length += d;
+        if (current_ls_length > max_split_distance_m) {
+          append_to.push_back(std::move(current_ls));
+          current_ls = linestring{*previous, p};
+          current_ls_length = d;
+        }
+      }
+      previous = p;
+    });
+    append_to.emplace_back(std::move(current_ls));
+  }
+
+} // namespace routemon::geo
-- 
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