3 files changed, 69 insertions, 16 deletions

diff --git a/lib/include/graph.hpp b/lib/include/graph.hpp
index c78fe9f..5ad4c8b 100644
--- a/lib/include/graph.hpp
+++ b/lib/include/graph.hpp
@@ -13,13 +13,44 @@
 
 #include "array_hash.hpp"
 
-class graph {
+class coordinate {
 public:
-  typedef struct coordinate {
-    double x;
-    double y;
-  } coordinate;
+  double x;
+  double y;
+
+  coordinate operator+(const coordinate& r) const {
+    coordinate rp = {0, 0};
+    rp.x = x + r.x;
+    rp.y = y + r.y;
+
+    return rp;
+  }
+
+  template <class T>
+  coordinate operator*(const T& a) const {
+    coordinate rp = *this;
+    rp.x *= a;
+    rp.y *= a;
+    return rp;
+  }
+
+  coordinate operator-(const coordinate& r) const {
+    coordinate rp = *this;
+    return rp + (r * -1);
+  }
+
+  coordinate operator-() const {
+    return *this * -1;
+  }
 
+  void operator+=(const coordinate& r) {
+    x += r.x;
+    y += r.y;
+  }
+};
+
+class graph {
+public:
   typedef struct vertex {
     coordinate r;
     std::vector<unsigned> nd;
@@ -49,4 +80,6 @@ public:
   graph const rotate();
 
   std::string write() const;
+
+  coordinate Δr(unsigned e) const;
 };
diff --git a/lib/src/graph.cpp b/lib/src/graph.cpp
index c75d466..1c770e9 100644
--- a/lib/src/graph.cpp
+++ b/lib/src/graph.cpp
@@ -445,14 +445,14 @@ void graph::helper(unsigned nv, std::mt19937& rng) {
   jcv_diagram_free(&diagram);
 }
 
-graph::coordinate reverse(const graph::coordinate& x) { return {x.y, x.x}; }
+coordinate reverse(const coordinate& x) { return {x.y, x.x}; }
 
 graph const graph::rotate() {
   graph g2(*this);
 
   for (graph::vertex& v : g2.vertices) {
     v.r = reverse(v.r);
-    for (graph::coordinate& r : v.polygon) {
+    for (coordinate& r : v.polygon) {
       r = reverse(r);
     }
   }
@@ -464,7 +464,7 @@ graph const graph::rotate() {
 
   for (graph::vertex& v : g2.dual_vertices) {
     v.r = reverse(v.r);
-    for (graph::coordinate& r : v.polygon) {
+    for (coordinate& r : v.polygon) {
       r = reverse(r);
     }
   }
@@ -490,7 +490,7 @@ std::string graph::write() const {
   output += "},\"vp\"->{";
   for (const graph::vertex &v : vertices) {
     output += "{";
-    for (const graph::coordinate &r : v.polygon) {
+    for (const coordinate &r : v.polygon) {
       output += "{" + std::to_string(r.x) + "," + std::to_string(r.y) + "},";
     }
     output.pop_back();
@@ -505,7 +505,7 @@ std::string graph::write() const {
   output += "},\"up\"->{";
   for (const graph::vertex &v : dual_vertices) {
     output += "{";
-    for (const graph::coordinate &r : v.polygon) {
+    for (const coordinate &r : v.polygon) {
       output += "{" + std::to_string(r.x) + "," + std::to_string(r.y) + "},";
     }
     output.pop_back();
@@ -536,3 +536,23 @@ std::string graph::write() const {
 
   return output;
 }
+
+coordinate graph::Δr(unsigned e) const {
+  coordinate tmp = dual_vertices[dual_edges[e].v[1]].r - dual_vertices[dual_edges[e].v[0]].r;
+  if (dual_edges[e].crossings[0]) {
+    if (tmp.x > 0) {
+      tmp.x -= L.x;
+    } else {
+      tmp.x += L.x;
+    }
+  }
+  if (dual_edges[e].crossings[1]) {
+    if (tmp.y > 0) {
+      tmp.y -= L.y;
+    } else {
+      tmp.y += L.y;
+    }
+  }
+
+  return tmp;
+}
diff --git a/lib/src/problem.cpp b/lib/src/problem.cpp
index ab87b0c..a029d66 100644
--- a/lib/src/problem.cpp
+++ b/lib/src/problem.cpp
@@ -9,8 +9,8 @@ problem::problem(const graph& G, unsigned axis, cholmod_sparse* vcmat, cholmod_c
     : G(G), axis(axis), voltcurmat(vcmat), c(c) {
   b = CHOL_F(zeros)(G.vertices.size(), 1, CHOLMOD_REAL, c);
   for (unsigned i = 0; i < G.edges.size(); i++) {
-    graph::coordinate v0 = G.vertices[G.edges[i].v[0]].r;
-    graph::coordinate v1 = G.vertices[G.edges[i].v[1]].r;
+    coordinate v0 = G.vertices[G.edges[i].v[0]].r;
+    coordinate v1 = G.vertices[G.edges[i].v[1]].r;
 
     if (G.edges[i].crossings[axis]) {
       bool ind;
@@ -131,8 +131,8 @@ void problem::solve(std::vector<bool>& fuses) {
     } else {
       sol.currents[i] = ((double*)y->x)[i];
 
-      graph::coordinate v0 = G.vertices[G.edges[i].v[0]].r;
-      graph::coordinate v1 = G.vertices[G.edges[i].v[1]].r;
+      coordinate v0 = G.vertices[G.edges[i].v[0]].r;
+      coordinate v1 = G.vertices[G.edges[i].v[1]].r;
 
       if (G.edges[i].crossings[axis]) {
         bool comp;
@@ -196,8 +196,8 @@ void problem::break_edge(unsigned e, bool unbreak) {
   CHOL_F(free_sparse)(&perm_update_mat, c);
   CHOL_F(free_sparse)(&update_mat, c);
 
-  graph::coordinate r0 = G.vertices[v0].r;
-  graph::coordinate r1 = G.vertices[v1].r;
+  coordinate r0 = G.vertices[v0].r;
+  coordinate r1 = G.vertices[v1].r;
 
   if (G.edges[e].crossings[axis]) {
     bool ind;