Implement spring forces on net when importing format where positions …

…are not defined #25

include/TimedPetriNetEditor/PetriNet.hpp

@@ -821,7 +821,7 @@ bool convertTo(Net& net, TypeOfNet const type, std::string& error, std::vector<A
 //! saved. Should have the .json extension.
 //! \return error message in case of failure, else return dummy string.
 //-----------------------------------------------------------------------------
-std::string loadFromFile(Net& net, std::string const& filepath);
+std::string loadFromFile(Net& net, std::string const& filepath, bool& springify);
 
 //-----------------------------------------------------------------------------
 //! \brief Save the Petri net in a a file.

src/Editor/DearImGui/Editor.cpp

@@ -124,11 +124,16 @@ void Editor::run(std::string const& filepath)
     // Load Petri net file if passed with command line
     if (!filepath.empty())
     {
-        std::string error = loadFromFile(m_net, filepath);
+        bool shall_springify;
+        std::string error = loadFromFile(m_net, filepath, shall_springify);
         if (error.empty())
         {
             m_messages.setInfo("Loaded with success " + filepath);
             setSavePath(filepath);
+            if (shall_springify)
+            {
+                springify();
+            }
         }
         else
         {
@@ -153,6 +158,7 @@ void Editor::onUpdate(float const dt)
     }
 
     m_simulation.step(dt);
+    m_spring.update();
 }
 
 //------------------------------------------------------------------------------
@@ -1002,7 +1008,7 @@ Transition* Editor::getTransition(ImVec2 const& position)
 //------------------------------------------------------------------------------
 void Editor::loadNetFile()
 {
-    static Importer importer{"TimedPetriNetEditor", ".json", importFromJSON};
+    static Importer importer{"TimedPetriNetEditor", ".json", importFromJSON, false};
     importNetFrom(importer);
 }
 
@@ -1039,12 +1045,17 @@ void Editor::importNetFrom(Importer const& importer)
                     m_messages.setInfo("Loaded with success '" + filepath + "'");
                 setSavePath(filepath);
                 m_net.modified = false;
+                if (importer.springify)
+                {
+                    springify();
+                }
             }
             else
             {
                 m_messages.setError(error);
                 m_net.clear();
                 m_net.modified = true;
+                m_spring.reset();
             }
         }
 
@@ -1055,6 +1066,12 @@ void Editor::importNetFrom(Importer const& importer)
     }
 }
 
+//--------------------------------------------------------------------------
+void Editor::springify()
+{
+    m_spring.reset(m_view.size().x, m_view.size().y, m_net);
+}
+
 //--------------------------------------------------------------------------
 void Editor::saveNetAs()
 {
@@ -1562,6 +1579,10 @@ void Editor::PetriView::onHandleInput()
         {
             handleMoveNode();
         }
+        else if (ImGui::IsKeyPressed(KEY_SPRINGIFY_NET))
+        {
+            m_editor.springify();
+        }
         // Run the animation of the Petri net
         else if (ImGui::IsKeyPressed(KEY_RUN_SIMULATION) ||
                  ImGui::IsKeyPressed(KEY_RUN_SIMULATION_ALT))

src/Editor/DearImGui/Editor.hpp

@@ -26,6 +26,7 @@
 #  include "Net/Simulation.hpp"
 #  include "Net/Exports/Exports.hpp"
 #  include "Net/Imports/Imports.hpp"
+#  include "Utils/ForceDirected.hpp"
 #  include "Utils/History.hpp"
 #  include "Utils/Path.hpp"
 #  include <vector>
@@ -94,6 +95,7 @@ class Editor: public PetriNetEditor, public Application
     void clearNet();
     void undo();
     void redo();
+    void springify();
 
 private: // Error logs
 
@@ -195,9 +197,12 @@ class Editor: public PetriNetEditor, public Application
         // ********************************************************************
         struct Canvas
         {
-            ImVec2 corners[2];
-            ImVec2 size;
-            ImVec2 origin;
+            ImVec2 corners[2] = {{0.0f, 0.0f}, {0.0f, 0.0f}};
+            ImVec2 size{800.0f, 600.0f}; // FIXME: size is undefined while not
+                                         // rendered once but when importing nets
+                                         // we need to know th windows size which
+                                         // is 0x0
+            ImVec2 origin{0.0f, 0.0f};
             ImVec2 scrolling{0.0f, 0.0f};
             ImDrawList* draw_list;
 
@@ -272,6 +277,9 @@ class Editor: public PetriNetEditor, public Application
     //! \brief Single Petri net the editor can edit.
     //! \fixme Manage several nets (like done with GEMMA).
     Net m_net;
+    //! Apply spring positive/negative forces on arcs/nodes to unfold imported
+    //! Petri nets that do not have positions on their nodes.
+    ForceDirected m_spring;
     //! \brief History of modifications of the net.
     History m_history;
     //! \brief Instance allowing to do timed simulation.

src/Editor/DearImGui/KeyBindings.hpp

@@ -25,6 +25,7 @@
 // FIXME: The backend raylib does not support other than US keyboard meaning that
 // other keyboard mapping are fucked up.
 #  define KEY_QUIT_APPLICATION      ImGuiKey_Escape
+#  define KEY_SPRINGIFY_NET         ImGuiKey_A
 #  define KEY_RUN_SIMULATION        ImGuiKey_Space
 #  define KEY_RUN_SIMULATION_ALT    ImGuiKey_R
 #  define KEY_ROTATE_CW             ImGuiKey_PageUp

src/Net/Imports/ImportTimedEventGraph.cpp

@@ -74,7 +74,7 @@ std::string importFromTimedEventGraph(Net& net, std::string const& filename)
     size_t x = margin, y = margin;
     for (size_t id = 0u; id < transitions; ++id)
     {
-        net.addTransition(id, Transition::to_str(id), float(x), float(y), 0);
+        net.addTransition(id, Transition::to_str(id), randomInt(0,800), randomInt(0,600), 0);
         x += dx;
         if (x > w - margin) { x = margin; y += dy; }
     }

src/Net/Imports/Imports.cpp

@@ -26,10 +26,10 @@ namespace tpne {
 std::vector<Importer> const& importers()
 {
     static const std::vector<Importer> s_importers = {
-        { "JSON", ".json", importFromJSON },
-        { "Petri Net Markup Language", ".pnml", importFromPNML },
-        { "Flowshop", ".flowshop", importFlowshop },
-        { "Timed Event Graph", ".teg", importFromTimedEventGraph }
+        { "JSON", ".json", importFromJSON, false },
+        { "Petri Net Markup Language", ".pnml", importFromPNML, false },
+        { "Flowshop", ".flowshop", importFlowshop, false },
+        { "Timed Event Graph", ".teg", importFromTimedEventGraph, true }
     };
 
     return s_importers;

src/Net/Imports/Imports.hpp

@@ -55,6 +55,8 @@ struct Importer
     std::string extensions;
     //! \brief the pointer function for importing (i.e. importFromJSON)
     ImportFunc importFct;
+    //! \brief Shall apply spring force on the net ?
+    bool springify;
 };
 
 //! \brief Container of file formats we can import a Petri net from.

src/Net/PetriNet.cpp

@@ -755,7 +755,7 @@ std::string saveToFile(Net const& net, std::string const& filepath)
 }
 
 //------------------------------------------------------------------------------
-std::string loadFromFile(Net& net, std::string const& filepath)
+std::string loadFromFile(Net& net, std::string const& filepath, bool& springify)
 {
     // Search the importer
     Importer const* importer = getImporter(extension(filepath));
@@ -771,6 +771,10 @@ std::string loadFromFile(Net& net, std::string const& filepath)
     {
         net.reset(net.type());
     }
+    else
+    {
+        springify = importer->springify;
+    }
 
     // Get a name to the net
     if (net.name == "")

src/Utils/ForceDirected.cpp

@@ -0,0 +1,150 @@
+/* *****************************************************************************
+** MIT License
+**
+** Copyright (c) 2022 Quentin Quadrat
+**
+** Permission is hereby granted, free of charge, to any person obtaining a copy
+** of this software and associated documentation files (the "Software"), to deal
+** in the Software without restriction, including without limitation the rights
+** to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+** copies of the Software, and to permit persons to whom the Software is
+** furnished to do so, subject to the following conditions:
+**
+** The above copyright notice and this permission notice shall be included in all
+** copies or substantial portions of the Software.
+**
+** THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+** IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+** FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+** AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+** LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+** OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+** SOFTWARE.
+********************************************************************************
+*/
+
+#include "Utils/ForceDirected.hpp"
+
+namespace tpne {
+
+//------------------------------------------------------------------------------
+void ForceDirected::reset(float width, float height, Net& net)
+{
+    std::cout << "ForceDirected::reset " << width << " x " << height << "\n";
+    m_net = &net;
+    m_width = width;
+    m_height = height;
+
+    N = net.transitions().size() + net.places().size();
+    K = sqrtf(m_width * m_height / 2.0f / float(N));
+    m_temperature = m_width + m_height;
+    m_vertices.clear();
+    m_vertices.reserve(N);
+
+    // Copy Petri nodes to Graph vertices
+    for (auto& it: net.transitions())
+    {
+        m_vertices.emplace_back(it);
+    }
+    for (auto& it: net.places())
+    {
+        m_vertices.emplace_back(it);
+    }
+
+    // Lookup table: Node ID to index on the vector
+    std::map<std::string, size_t> lookup;
+    for (size_t n = 0u; n < N; ++n)
+    {
+        lookup[m_vertices[n].node->key] = n;
+    }
+
+    // Add edges "source node" -> "destination node".
+    // Since, we need undirected graph so add edges "destination node" -> "source node"
+    for (size_t n = 0u; n < N; ++n)
+    {
+        Vertex& v = m_vertices[n];
+        v.neighbors.reserve(2u * (v.node->arcsIn.size() + v.node->arcsOut.size()));
+
+        for (auto& it: v.node->arcsIn)
+        {
+            v.neighbors.emplace_back(m_vertices[lookup[it->from.key]].node);
+            v.neighbors.emplace_back(m_vertices[lookup[it->to.key]].node);
+        }
+
+        for (auto& it: v.node->arcsOut)
+        {
+            v.neighbors.emplace_back(m_vertices[lookup[it->from.key]].node);
+            v.neighbors.emplace_back(m_vertices[lookup[it->to.key]].node);
+        }
+    }
+}
+
+//------------------------------------------------------------------------------
+void ForceDirected::update()
+{
+    if (m_net == nullptr)
+        return ;
+
+    if (m_temperature < 0.1f)
+        return ;
+
+    step();
+}
+
+//------------------------------------------------------------------------------
+void ForceDirected::step()
+{
+    if (m_net == nullptr)
+        return ;
+
+    for (auto& v: m_vertices)
+    {
+        const ImVec2 v_position(v.node->x, v.node->y);
+
+        // Repulsive forces: nodes -- nodes
+        for (auto& u: m_vertices)
+        {
+            if (u.node->key == v.node->key)
+                continue ;
+
+            const ImVec2 u_position(u.node->x, u.node->y);
+            const ImVec2 direction(v_position - u_position);
+            const float dist = distance(direction);
+            const float rf = repulsive_force(dist);
+            v.displacement += direction * rf / dist;
+        }
+
+        // Attractive forces: edges
+        for (auto& u: v.neighbors)
+        {
+            if (u->key == v.node->key)
+                continue ;
+
+            const ImVec2 u_position(u->x, u->y);
+            const ImVec2 direction(v_position - u_position);
+            const float dist = distance(direction);
+            const float af = attractive_force(dist);
+            v.displacement -= direction * af / dist;
+        }
+    }
+
+    // Update position and constrain position to the window bounds
+    for (auto& v: m_vertices)
+    {
+        constexpr ImVec2 LAYOUT_BORDER(50.0f, 50.0f);
+        const float dist = distance(v.displacement);
+        ImVec2 v_position(v.node->x, v.node->y);
+        v_position += (dist > m_temperature)
+                      ? v.displacement * m_temperature / dist
+                      : v.displacement;
+        v.node->x = std::min(m_width - LAYOUT_BORDER.x,
+                             std::max(LAYOUT_BORDER.x, v_position.x));
+        v.node->y = std::min(m_height - LAYOUT_BORDER.y,
+                             std::max(LAYOUT_BORDER.y, v_position.y));
+        v.displacement = { 0.0f, 0.0f };
+    }
+
+    cooling();
+}
+
+} // namespace tpne