From 701e174788859528841ab794a01af478c173ea55 Mon Sep 17 00:00:00 2001
From: AnastasiaDolotova <ad4019809@gmail.com>
Date: Wed, 28 Sep 2022 23:44:51 +0300
Subject: [PATCH] Method insertNodesIntoMiddles() was implemented

---
 DataTypes.h    | 15 +++++++++++++-
 MeshLoader.cpp | 56 +++++++++++++++++++++++++++++++++++++++++++++++---
 MeshLoader.h   |  2 ++
 3 files changed, 69 insertions(+), 4 deletions(-)

diff --git a/DataTypes.h b/DataTypes.h
index 2ea1e9f..5a1f7f5 100644
--- a/DataTypes.h
+++ b/DataTypes.h
@@ -29,7 +29,7 @@ struct FiniteElement {
 
     FiniteElement(unsigned int p_ID, unsigned int p_areaID,
                   std::vector<unsigned int> &p_nodesID) : ID(p_ID),
-                                                         areaID(p_areaID), nodesID(p_nodesID) {}
+                                                          areaID(p_areaID), nodesID(p_nodesID) {}
 
     friend std::ostream &operator<<(std::ostream &ost, const FiniteElement &element) {
         ost << "ID: " << element.ID << ", area ID: " << element.areaID << ", nodes ID: {";
@@ -60,4 +60,17 @@ struct BoundaryElement {
         ost << "\b" << "}";
         return ost;
     }
+};
+
+struct Edge {
+    unsigned int node1, node2, middleNode;
+
+    Edge() = default;
+
+    Edge(unsigned int p_node1, unsigned int p_node2, unsigned int mid) : node1(std::min(p_node1, p_node2)),
+                                                       node2(std::max(p_node1, p_node2)), middleNode(mid) {}
+
+    bool operator==(const Edge &edge) const {
+        return node1 == edge.node1 && node2 == edge.node2;
+    }
 };
\ No newline at end of file
diff --git a/MeshLoader.cpp b/MeshLoader.cpp
index fddba28..2cb7f58 100644
--- a/MeshLoader.cpp
+++ b/MeshLoader.cpp
@@ -72,7 +72,7 @@ std::unordered_set<unsigned int> MeshLoader::getBoundaryNodesByBoundaryID(unsign
 std::vector<FiniteElement> MeshLoader::getFiniteElementsByAreaID(unsigned int ID) {
     std::vector<FiniteElement> elements;
     auto beg = finiteElements.begin(), end = finiteElements.end();
-    while(beg != end){
+    while (beg != end) {
         auto e = std::find_if(beg, end,
                               [ID](const FiniteElement &elem) -> bool {
                                   return elem.areaID == ID;
@@ -89,7 +89,7 @@ std::vector<FiniteElement> MeshLoader::getFiniteElementsByAreaID(unsigned int ID
 std::vector<BoundaryElement> MeshLoader::getBoundaryElementsByBoundaryID(unsigned int ID) {
     std::vector<BoundaryElement> elements;
     auto beg = boundaryElements.begin(), end = boundaryElements.end();
-    while(beg != end){
+    while (beg != end) {
         auto e = std::find_if(beg, end,
                               [ID](const BoundaryElement &elem) -> bool {
                                   return elem.boundaryID == ID;
@@ -104,7 +104,57 @@ std::vector<BoundaryElement> MeshLoader::getBoundaryElementsByBoundaryID(unsigne
 }
 
 void MeshLoader::insertNodesIntoMiddles() {
-    //TODO
+    auto hash = [](const Edge &element) {
+        unsigned int hashcode = 23;
+        hashcode = (hashcode * 37) + element.node1;
+        hashcode = (hashcode * 37) + element.node2;
+        return hashcode;
+    };
+
+    std::unordered_set<Edge, decltype(hash)> edges;
+
+    for (auto &element: finiteElements) {
+        size_t size = element.nodesID.size();
+        for (int i = 0; i < size; ++i) {
+            for (int j = i + 1; j < size; ++j) {
+                Edge edge(element.nodesID[i], element.nodesID[j], nodes.size() + 1);
+                auto[iter, res] = edges.insert(edge);
+                if (res) {
+                    Node node = makeMiddleNode(edge.node1, edge.node2);
+                    edge.middleNode = node.ID;
+                    nodes.push_back(node);
+                    element.nodesID.push_back(node.ID);
+                } else {
+                    element.nodesID.push_back(iter->middleNode);
+                }
+            }
+        }
+    }
+
+    for (auto &element: boundaryElements) {
+        size_t size = element.nodesID.size();
+        for (int i = 0; i < size; ++i) {
+            for (int j = i + 1; j < size; ++j) {
+                unsigned int ID1 = element.nodesID[i];
+                unsigned int ID2 = element.nodesID[j];
+                Edge edge(ID1, ID2, 0);
+                auto iter = edges.find(edge);
+                element.nodesID.push_back(iter->middleNode);
+            }
+        }
+    }
+}
+
+Node MeshLoader::makeMiddleNode(unsigned int ID1, unsigned int ID2) {
+    unsigned int ID = nodes.size() + 1;
+    ID1--;
+    ID2--;
+    double x = (nodes[ID1].x + nodes[ID2].x) / 2;
+    double y = (nodes[ID1].y + nodes[ID2].y) / 2;
+    double z = (nodes[ID1].z + nodes[ID2].z) / 2;
+    bool isVertex = nodes[ID1].isVertex && nodes[ID2].isVertex;
+    Node node{ID, x, y, z, isVertex};
+    return node;
 }
 
 std::vector<std::unordered_set<unsigned int>> MeshLoader::makeVectorOfNeighbours() {
diff --git a/MeshLoader.h b/MeshLoader.h
index 2c4bebe..bd743bd 100644
--- a/MeshLoader.h
+++ b/MeshLoader.h
@@ -38,6 +38,8 @@ public:
 
     void insertNodesIntoMiddles();
 
+    Node makeMiddleNode(unsigned int, unsigned int);
+
     std::vector<std::unordered_set<unsigned int>> makeVectorOfNeighbours();
 
     virtual ~MeshLoader() = default;
-- 
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