moved

Sapfor/_src/VisualizerCalls/graphLayout/kamada_kawai.hpp

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+#pragma once
+#include "nodesoup.hpp"
+#include <vector>
+
+namespace nodesoup {
+// https://gist.github.com/terakun/b7eff90c889c1485898ec9256ca9f91d
+// https://graphsharp.codeplex.com/SourceControl/latest#Source/Graph#/Algorithms/Layout/Simple/FDP/KKLayoutAlgorithm.cs
+class KamadaKawai {
+public:
+    struct Spring {
+        double length;
+        double strength;
+    };
+
+    KamadaKawai(const adj_list_t& g, double k = 300.0, double energy_threshold = 1e-2);
+    void operator()(std::vector<Point2D>& positions) const;
+
+private:
+    const adj_list_t& g_;
+    const double energy_threshold_;
+    std::vector<std::vector<Spring>> springs_;
+
+    static std::vector<std::vector<vertex_id_t>> floyd_warshall_(const adj_list_t& g);
+    // p m
+    double find_max_vertex_energy_(const std::vector<Point2D>& positions, vertex_id_t& max_energy_v_id) const;
+    // delta m
+    double compute_vertex_energy_(vertex_id_t v_id, const std::vector<Point2D>& positions) const;
+    Point2D compute_next_vertex_position_(vertex_id_t v_id, const std::vector<Point2D>& positions) const;
+};
+}