3 files changed, 22 insertions, 14 deletions
diff --git a/game/network/network.cpp b/game/network/network.cpp
index d78f672..ad501b5 100644
--- a/game/network/network.cpp
+++ b/game/network/network.cpp
@@ -19,14 +19,15 @@ Network::nodeAt(glm::vec3 pos)
 	return newNodeAt(pos).first;
 }
 
-std::pair<Node::Ptr, bool>
+Network::NodeInsertion
 Network::newNodeAt(glm::vec3 pos)
 {
-	const auto [n, i] = candidateNodeAt(pos);
-	if (!i) {
-		nodes.insert(n);
+	if (const auto [n, i] = candidateNodeAt(pos); i == NodeIs::NotInNetwork) {
+		return {*nodes.insert(std::move(n)).first, i};
+	}
+	else {
+		return {n, NodeIs::InNetwork};
 	}
-	return {n, !i};
 }
 
 Node::Ptr
@@ -38,13 +39,13 @@ Network::findNodeAt(glm::vec3 pos) const
 	return {};
 }
 
-std::pair<Node::Ptr, bool>
+Network::NodeInsertion
 Network::candidateNodeAt(glm::vec3 pos) const
 {
 	if (const auto n = nodes.find(pos); n != nodes.end()) {
-		return {*n, true};
+		return {*n, NodeIs::InNetwork};
 	}
-	return {std::make_shared<Node>(pos), false};
+	return {std::make_shared<Node>(pos), NodeIs::NotInNetwork};
 }
 
 Node::Ptr
diff --git a/game/network/network.h b/game/network/network.h
index b95dfdc..25f0200 100644
--- a/game/network/network.h
+++ b/game/network/network.h
@@ -23,8 +23,10 @@ public:
 
 	[[nodiscard]] Node::Ptr findNodeAt(glm::vec3) const;
 	[[nodiscard]] Node::Ptr nodeAt(glm::vec3);
-	[[nodiscard]] std::pair<Node::Ptr, bool> newNodeAt(glm::vec3);
-	[[nodiscard]] std::pair<Node::Ptr, bool> candidateNodeAt(glm::vec3) const;
+	enum class NodeIs { InNetwork, NotInNetwork };
+	using NodeInsertion = std::pair<Node::Ptr, NodeIs>;
+	[[nodiscard]] NodeInsertion newNodeAt(glm::vec3);
+	[[nodiscard]] NodeInsertion candidateNodeAt(glm::vec3) const;
 	[[nodiscard]] virtual Link::Ptr intersectRayLinks(const Ray &) const = 0;
 	[[nodiscard]] virtual Node::Ptr intersectRayNodes(const Ray &) const;
 
@@ -85,4 +87,7 @@ public:
 	Link::CCollection addExtend(glm::vec3, glm::vec3) override;
 
 	void render(const Shader &) const override;
+
+protected:
+	Link::CCollection addJoins();
 };
diff --git a/game/network/rail.cpp b/game/network/rail.cpp
index 635ee6e..95b6d24 100644
--- a/game/network/rail.cpp
+++ b/game/network/rail.cpp
@@ -30,11 +30,11 @@ std::shared_ptr<RailLink>
 RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
 {
 	auto node1ins = newNodeAt(start), node2ins = newNodeAt(end);
-	if (node1ins.second && node2ins.second) {
+	if (node1ins.second == NodeIs::NotInNetwork && node2ins.second == NodeIs::NotInNetwork) {
 		// Both nodes are new, direct link, easy
 		return addLink<RailLinkStraight>(start, end);
 	}
-	if (node1ins.second && !node2ins.second) {
+	if (node1ins.second == NodeIs::NotInNetwork && node2ins.second == NodeIs::InNetwork) {
 		// node1 is new, node2 exists, but we build from existing outwards
 		std::swap(node1ins, node2ins);
 		std::swap(start, end);
@@ -56,7 +56,7 @@ RailLinks::addLinksBetween(glm::vec3 start, glm::vec3 end)
 		return addLink<RailLinkStraight>(start, end);
 	}
 	const glm::vec2 flatStart {!start}, flatEnd {!end};
-	if (!node2ins.second) {
+	if (node2ins.second == NodeIs::InNetwork) {
 		auto midheight = [&](auto mid) {
 			const auto sm = glm::distance(flatStart, mid), em = glm::distance(flatEnd, mid);
 			return start.z + ((end.z - start.z) * (sm / (sm + em)));
@@ -128,7 +128,9 @@ round_sleepers(const float v)
 	return round_frac(v, sleepers);
 }
 
-RailLinkStraight::RailLinkStraight(const Node::Ptr & a, const Node::Ptr & b) : RailLinkStraight(a, b, b->pos - a->pos) { }
+RailLinkStraight::RailLinkStraight(const Node::Ptr & a, const Node::Ptr & b) : RailLinkStraight(a, b, b->pos - a->pos)
+{
+}
 
 RailLinkStraight::RailLinkStraight(Node::Ptr a, Node::Ptr b, const glm::vec3 & diff) :
 	Link({std::move(a), vector_yaw(diff)}, {std::move(b), vector_yaw(-diff)}, glm::length(diff))