5 files changed, 39 insertions, 31 deletions
diff --git a/game/network/network.cpp b/game/network/network.cpp
index 52d88ec..fd61764 100644
--- a/game/network/network.cpp
+++ b/game/network/network.cpp
@@ -1,7 +1,9 @@
 #include "network.h"
+#include <array>
 #include <cache.h>
 #include <game/network/link.h>
 #include <gfx/models/texture.h>
+#include <initializer_list>
 #include <utility>
 
 Network::Network(const std::string & tn) : texture {Texture::cachedTexture.get(tn)} { }
@@ -27,3 +29,18 @@ Network::findNodeAt(glm::vec3 pos) const
 	}
 	return {};
 }
+
+void
+Network::joinLinks(const LinkPtr & l, const LinkPtr & ol)
+{
+	if (l != ol) {
+		for (const auto oe : {0, 1}) {
+			for (const auto te : {0, 1}) {
+				if (l->ends[te].node == ol->ends[oe].node) {
+					l->ends[te].nexts.emplace_back(ol, oe);
+					ol->ends[oe].nexts.emplace_back(l, te);
+				}
+			}
+		}
+	}
+}
diff --git a/game/network/network.h b/game/network/network.h
index c42f056..c6d4dfa 100644
--- a/game/network/network.h
+++ b/game/network/network.h
@@ -23,6 +23,8 @@ public:
 	[[nodiscard]] std::pair<NodePtr, bool> newNodeAt(glm::vec3);
 
 protected:
+	static void joinLinks(const LinkPtr & l, const LinkPtr & ol);
+
 	using Nodes = std::set<NodePtr, PtrSorter<NodePtr>>;
 	Nodes nodes;
 	std::shared_ptr<Texture> texture;
@@ -33,8 +35,19 @@ protected:
 	using Network::Network;
 
 	Collection<T> links;
+	void joinLinks(const LinkPtr &) const;
 
 public:
+	template<typename L, typename... Params>
+	std::shared_ptr<L>
+	addLink(glm::vec3 a, glm::vec3 b, Params &&... params) requires std::is_base_of_v<T, L>
+	{
+		const auto node1 = nodeAt(a), node2 = nodeAt(b);
+		auto l {links.template create<L>(node1, node2, std::forward<Params>(params)...)};
+		joinLinks(l);
+		return l;
+	}
+
 	void render(const Shader &) const override;
 };
 
diff --git a/game/network/network.impl.h b/game/network/network.impl.h
index ddb1ae5..699cb94 100644
--- a/game/network/network.impl.h
+++ b/game/network/network.impl.h
@@ -10,3 +10,12 @@ NetworkOf<T>::render(const Shader & shader) const
 	texture->Bind();
 	links.apply(&T::render, shader);
 }
+
+template<typename T>
+void
+NetworkOf<T>::joinLinks(const LinkPtr & l) const
+{
+	for (const auto & ol : links.objects) {
+		Network::joinLinks(l, ol);
+	}
+}
diff --git a/game/network/rail.cpp b/game/network/rail.cpp
index 7cc6284..0ef58d7 100644
--- a/game/network/rail.cpp
+++ b/game/network/rail.cpp
@@ -7,7 +7,6 @@
 #include <game/network/network.impl.h> // IWYU pragma: keep
 #include <gfx/models/vertex.hpp>
 #include <glm/gtx/transform.hpp>
-#include <initializer_list>
 #include <location.hpp>
 #include <maths.h>
 #include <stdexcept>
@@ -22,23 +21,6 @@ constexpr glm::vec3 RAIL_HEIGHT {0, .25F, 0};
 RailLinks::RailLinks() : NetworkOf<RailLink> {"rails.jpg"} { }
 void RailLinks::tick(TickDuration) { }
 
-void
-RailLinks::joinLinks(const LinkPtr & l) const
-{
-	for (const auto & ol : links.objects) {
-		if (l != ol) {
-			for (const auto oe : {0, 1}) {
-				for (const auto te : {0, 1}) {
-					if (l->ends[te].node == ol->ends[oe].node) {
-						l->ends[te].nexts.emplace_back(ol, oe);
-						ol->ends[oe].nexts.emplace_back(l, te);
-					}
-				}
-			}
-		}
-	}
-}
-
 std::shared_ptr<RailLink>
 RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
 {
diff --git a/game/network/rail.h b/game/network/rail.h
index 3b3da42..3ecc59f 100644
--- a/game/network/rail.h
+++ b/game/network/rail.h
@@ -11,7 +11,6 @@
 #include <maths.h>
 #include <memory>
 #include <span>
-#include <utility>
 
 class Shader;
 class Vertex;
@@ -50,26 +49,14 @@ private:
 	Arc arc;
 };
 
-template<typename T> concept RailLinkConcept = std::is_base_of_v<RailLink, T>;
-
 class RailLinks : public NetworkOf<RailLink>, public WorldObject {
 public:
 	RailLinks();
-	template<RailLinkConcept T, typename... Params>
-	std::shared_ptr<T>
-	addLink(glm::vec3 a, glm::vec3 b, Params &&... params)
-	{
-		const auto node1 = nodeAt(a), node2 = nodeAt(b);
-		auto l {links.create<T>(node1, node2, std::forward<Params>(params)...)};
-		joinLinks(l);
-		return l;
-	}
 
 	std::shared_ptr<RailLink> addLinksBetween(glm::vec3 start, glm::vec3 end);
 
 private:
 	void tick(TickDuration elapsed) override;
-	void joinLinks(const LinkPtr &) const;
 };
 
 #endif