1 files changed, 126 insertions, 0 deletions
diff --git a/Project/GraphAutoLayout.cpp b/Project/GraphAutoLayout.cpp
new file mode 100644
index 0000000..972ce25
--- /dev/null
+++ b/Project/GraphAutoLayout.cpp
@@ -0,0 +1,126 @@
+#include "GraphAutoLayout.h"
+//#include "ImportForm.h"
+
+GraphAutoLayout::GraphAutoLayout() {}
+
+GraphAutoLayout::~GraphAutoLayout() {}
+
+GraphAutoLayout::GraphAutoLayout(std::vector<ParseMatpower::BusData*> busData,
+                                 std::vector<ParseMatpower::BranchData*> branchData)
+{
+    m_busData = busData;
+    m_branchData = branchData;
+    for(auto it = m_busData.begin(); it != m_busData.end(); ++it) {
+        GraphLayoutNode node;
+        m_nodes.push_back(node);
+    }
+    for(auto it = m_branchData.begin(); it != m_branchData.end(); ++it) {
+        ParseMatpower::BranchData* branch = *it;
+        float weight = 1.0;
+        if(branch->tap > 1e-3) weight = 2.0;
+        AddLink(branch->busConnections.first - 1, branch->busConnections.second - 1, weight);
+    }
+}
+
+void GraphAutoLayout::AddLink(size_t index1, size_t index2, float weight)
+{
+    // If the two indices are the same, or if the weight is zero, do nothing (no link)
+    if(index1 == index2 || weight == 0.f) { return; }
+    // If the number of nodes is lesser than one of the indices, extend the nodes vector
+    size_t maxIndex = std::max(index1, index2);
+    size_t nodesMaxIndex = m_nodes.size() - 1;
+    for(size_t i = nodesMaxIndex; i < maxIndex; i++) {
+        GraphLayoutNode node;
+        m_nodes.push_back(node);
+    }
+    // Add an edge
+    m_edges.push_back((GraphLayoutEdge){.node1 = m_nodes[index1], .node2 = m_nodes[index2], .weight = weight});
+}
+
+void GraphAutoLayout::Compute(size_t iterations)
+{
+    wxProgressDialog pbd(_("Importing..."), _("Initializing..."), iterations, NULL,
+                         wxPD_APP_MODAL | wxPD_AUTO_HIDE | wxPD_CAN_ABORT | wxPD_SMOOTH);
+
+    float nodesCount = m_nodes.size();
+
+    // Initialize nodes positions on a circle
+    float a = 0.f;
+    float da = 2.f * M_PI / nodesCount;
+    for(auto node = m_nodes.begin(); node != m_nodes.end(); node++) {
+        node->position.x = nodesCount * std::cos(a);
+        node->position.y = nodesCount * std::sin(a);
+        a += da;
+    }
+
+    // Initial parameters; other values can be chosen for area;
+    float area = nodesCount;
+    float k2 = area / nodesCount;
+    float k = sqrt(k2);
+
+    for(size_t i = 0; i < iterations; i++) {
+        // Temperature cools down; starts at 1, ends at 0
+        // (other formulas can be used for the cooling)
+        float temperature = 1.f - i / (float)iterations;
+        temperature *= temperature;
+
+        // Calculate repulsive forces
+        for(auto node1 = m_nodes.begin(); node1 != m_nodes.end(); node1++) {
+            node1->displacement = {0.f, 0.f};
+            for(auto node2 = m_nodes.begin(); node2 != m_nodes.end(); node2++) {
+                float dx = node1->position.x - node2->position.x;
+                float dy = node1->position.y - node2->position.y;
+                if(dx && dy) {
+                    float d2 = dx * dx + dy * dy;
+                    float coefficient = k2 / d2;
+                    node1->displacement.x += coefficient * dx;
+                    node1->displacement.y += coefficient * dy;
+                }
+            }
+        }
+
+        // Calculate attractive forces
+        for(auto edge = m_edges.begin(); edge != m_edges.end(); edge++) {
+            float dx = edge->node1.position.x - edge->node2.position.x;
+            float dy = edge->node1.position.y - edge->node2.position.y;
+            float d2 = dx * dx + dy * dy;
+            float coefficient = sqrt(d2) / k * edge->weight;
+            edge->node1.displacement.x -= dx * coefficient;
+            edge->node1.displacement.y -= dy * coefficient;
+            edge->node2.displacement.x += dx * coefficient;
+            edge->node2.displacement.y += dy * coefficient;
+        }
+
+        //  Calculate positions
+        float sum = 0.f;
+        for(auto node = m_nodes.begin(); node != m_nodes.end(); node++) {
+            float d2 = node->displacement.x * node->displacement.x + node->displacement.y * node->displacement.y;
+            float d = sqrt(d2);
+            if(d > temperature) {
+                float coefficient = temperature / d;
+                node->displacement.x *= coefficient;
+                node->displacement.y *= coefficient;
+                sum += temperature;
+            } else {
+                sum += d;
+            }
+            node->position.x += node->displacement.x;
+            node->position.y += node->displacement.y;
+        }
+
+        if(!pbd.Update(i, wxString::Format("Iteration = %d", i))) {
+            pbd.Update(iterations);
+            i = iterations;
+        }
+    }
+}
+
+void GraphAutoLayout::CalculatePositions(int iterations, double scale)
+{
+    Compute(iterations);
+    int index = 0;
+    for(auto it = m_busData.begin(); it != m_busData.end(); ++it) {
+        (*it)->busPosition = wxPoint2DDouble(m_nodes[index].position.x * scale, m_nodes[index].position.y * scale);
+        index++;
+    }
+}