[2768] | 1 | using System;
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[4068] | 2 | using System.Collections.Generic;
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| 3 | using System.ComponentModel;
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| 4 | using System.Drawing;
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[2768] | 5 | using Netron.Diagramming.Core.Analysis;
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| 6 | using Netron.Diagramming.Core.Layout.Force;
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| 7 |
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[4068] | 8 | namespace Netron.Diagramming.Core {
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| 9 | /// <summary>
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| 10 | /// <para>Layout that positions graph elements based on a physics simulation of
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| 11 | /// interacting forces; by default, nodes repel each other, edges act as
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| 12 | /// springs, and drag forces (similar to air resistance) are applied. This
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| 13 | /// algorithm can be run for multiple iterations for a run-once layout
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| 14 | /// computation or repeatedly run in an animated fashion for a dynamic and
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| 15 | /// interactive layout.</para>
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| 16 | ///
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| 17 | /// <para>The running time of this layout algorithm is the greater of O(N log N)
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| 18 | /// and O(E), where N is the number of nodes and E the number of edges.
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| 19 | /// The addition of custom force calculation modules may, however, increase
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| 20 | /// this value.</para>
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| 21 | ///
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| 22 | /// <para>The <see cref="ForceSimulator"/> used to drive this layout
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| 23 | /// can be set explicitly, allowing any number of custom force directed layouts
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| 24 | /// to be created through the user's selection of included
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| 25 | /// <see cref="Force"/> components. Each node in the layout is
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| 26 | /// mapped to a <see cref="ForceItem"/> instance and each edge
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| 27 | /// to a <see cref="Spring"/> instance for storing the state
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| 28 | /// of the simulation. See the <see cref="Force"/> namespace for more.</para>
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| 29 | /// </summary>
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| 30 | class ForceDirectedLayout : LayoutBase {
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| 31 | #region Fields
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| 32 | private ForceSimulator m_fsim;
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| 33 | private long m_lasttime = -1L;
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| 34 | private long m_maxstep = 50L;
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| 35 | private bool m_runonce;
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| 36 | private int m_iterations = 100;
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| 37 | private bool mEnforceBounds;
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| 38 | BackgroundWorker worker;
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| 39 | protected INode referrer;
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[2768] | 40 |
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[4068] | 41 | protected String m_nodeGroup;
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| 42 | protected String m_edgeGroup;
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| 43 | private Dictionary<string, ForceItem> Pars;
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| 44 | #endregion
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[2768] | 45 |
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[4068] | 46 | #region Properties
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| 47 | public long MaxTimeStep {
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| 48 | get { return m_maxstep; }
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| 49 | set { m_maxstep = value; }
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| 50 | }
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[2768] | 51 |
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[4068] | 52 | public ForceSimulator getForceSimulator {
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| 53 | get { return m_fsim; }
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| 54 | set { m_fsim = value; }
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| 55 | }
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[2768] | 56 |
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[4068] | 57 | public int Iterations {
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| 58 | get { return m_iterations; }
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| 59 | set {
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| 60 | if (value < 1)
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| 61 | throw new ArgumentException("The amount of iterations has to be bigger or equal to one.");
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| 62 | m_iterations = value;
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| 63 | }
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| 64 | }
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[2768] | 65 |
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| 66 |
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| 67 |
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[4068] | 68 | #endregion
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[2768] | 69 |
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[4068] | 70 | #region Constructor
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| 71 | ///<summary>
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| 72 | ///Default constructor
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| 73 | ///</summary>
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| 74 | public ForceDirectedLayout(IController controller)
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| 75 | : base("ForceDirected Layout", controller) {
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[2768] | 76 |
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[4068] | 77 | }
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| 78 | #endregion
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[2768] | 79 |
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[4068] | 80 | #region Methods
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| 81 | /// <summary>
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| 82 | /// Handles the DoWork event of the worker control.
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| 83 | /// </summary>
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| 84 | /// <param name="sender">The source of the event.</param>
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| 85 | /// <param name="e">The <see cref="T:System.ComponentModel.DoWorkEventArgs"/> instance containing the event data.</param>
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| 86 | private void worker_DoWork(object sender, DoWorkEventArgs e) {
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| 87 | this.Controller.View.Suspend();
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| 88 | Init();
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| 89 | Layout();
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| 90 | this.Controller.View.Resume();
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| 91 | }
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| 92 | /// <summary>
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| 93 | /// Runs this instance.
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| 94 | /// </summary>
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| 95 | public override void Run() {
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| 96 | Run(2000);
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| 97 | }
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[2768] | 98 |
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[4068] | 99 | /// <summary>
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| 100 | /// Runs the specified time.
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| 101 | /// </summary>
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| 102 | /// <param name="time">The time.</param>
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| 103 | public override void Run(int time) {
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| 104 | worker = new BackgroundWorker();
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| 105 | worker.DoWork += new DoWorkEventHandler(worker_DoWork);
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| 106 | worker.RunWorkerAsync(time);
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| 107 | }
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[2768] | 108 |
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[4068] | 109 | /// <summary>
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| 110 | /// Stops this instance.
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| 111 | /// </summary>
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| 112 | public override void Stop() {
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| 113 | if (worker != null && worker.IsBusy)
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| 114 | worker.CancelAsync();
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| 115 | }
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| 116 | ///<summary>
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| 117 | /// Get the mass value associated with the given node. Subclasses should
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| 118 | /// override this method to perform custom mass assignment.
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| 119 | /// @param n the node for which to compute the mass value
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| 120 | /// @return the mass value for the node. By default, all items are given
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| 121 | /// a mass value of 1.0.
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| 122 | ///</summary>
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| 123 | protected float getMassValue(INode n) {
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| 124 | return 1.0f;
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| 125 | }
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[2768] | 126 |
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[4068] | 127 | ///<summary>
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| 128 | /// Get the spring length for the given edge. Subclasses should
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| 129 | /// override this method to perform custom spring length assignment.
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| 130 | /// @param e the edge for which to compute the spring length
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| 131 | /// @return the spring length for the edge. A return value of
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| 132 | /// -1 means to ignore this method and use the global default.
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| 133 | ///</summary>
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| 134 | protected float getSpringLength(IEdge e) {
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| 135 | return -1.0F;
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| 136 | }
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[2768] | 137 |
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[4068] | 138 | ///<summary>
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| 139 | /// Get the spring coefficient for the given edge, which controls the
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| 140 | /// tension or strength of the spring. Subclasses should
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| 141 | /// override this method to perform custom spring tension assignment.
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| 142 | /// @param e the edge for which to compute the spring coefficient.
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| 143 | /// @return the spring coefficient for the edge. A return value of
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| 144 | /// -1 means to ignore this method and use the global default.
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| 145 | ///</summary>
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| 146 | protected float getSpringCoefficient(IEdge e) {
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| 147 | return -1.0F;
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| 148 | }
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[2768] | 149 |
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[4068] | 150 | private bool Init() {
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[2768] | 151 |
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[4068] | 152 | mEnforceBounds = false;
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| 153 | m_runonce = true;
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| 154 | m_fsim = new ForceSimulator();
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[2768] | 155 |
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[4068] | 156 | m_fsim.AddForce(new NBodyForce());
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| 157 | m_fsim.AddForce(new SpringForce());
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| 158 | m_fsim.AddForce(new DragForce());
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[2768] | 159 |
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[4068] | 160 | this.Graph = this.Model as IGraph;
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[2768] | 161 |
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[4068] | 162 | if (Graph == null)
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| 163 | throw new InconsistencyException("The model has not been set and the Graph property is hence 'null'");
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[2768] | 164 |
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[4068] | 165 | //Graph.ClearSpanningTree();
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| 166 | //Graph.MakeSpanningTree(LayoutRoot as INode);
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[2768] | 167 |
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| 168 |
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[4068] | 169 | if (Graph.Nodes.Count == 0)
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| 170 | return false;
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| 171 | if (Graph.Edges.Count == 0) //this layout is base on embedded springs in the connections
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| 172 | return false;
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[2768] | 173 |
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[4068] | 174 | Pars = new Dictionary<string, ForceItem>();
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[2768] | 175 |
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[4068] | 176 | foreach (INode node in Nodes) {
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| 177 | Pars.Add(node.Uid.ToString(), new ForceItem());
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| 178 | }
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| 179 | return true;
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| 180 | }
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[2768] | 181 |
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[4068] | 182 | /// <summary>
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| 183 | /// Updates the node positions.
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| 184 | /// </summary>
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| 185 | private void UpdateNodePositions() {
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| 186 | double x1 = 0, x2 = 0, y1 = 0, y2 = 0;
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[2768] | 187 |
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[4068] | 188 | if (Bounds != null) {
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| 189 | x1 = Bounds.X; y1 = Bounds.Top;
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| 190 | x2 = Bounds.Right; y2 = Bounds.Bottom;
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| 191 | }
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[2768] | 192 |
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[4068] | 193 | // update positions
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| 194 | foreach (INode item in Nodes) {
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[2768] | 195 |
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[4068] | 196 | ForceItem fitem = Pars[item.Uid.ToString()];
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| 197 | if (item.IsFixed) {
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| 198 | // clear any force computations
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| 199 | fitem.Force[0] = 0.0f;
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| 200 | fitem.Force[1] = 0.0f;
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| 201 | fitem.Velocity[0] = 0.0f;
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| 202 | fitem.Velocity[1] = 0.0f;
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[2768] | 203 |
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[4068] | 204 | if (Double.IsNaN(item.X)) {
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| 205 | setX(item, referrer, 0.0D);
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| 206 | setY(item, referrer, 0.0D);
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| 207 | }
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| 208 | continue;
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| 209 | }
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[2768] | 210 |
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[4068] | 211 | double x = fitem.Location[0];
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| 212 | double y = fitem.Location[1];
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| 213 | //do we need to check the bounding constraints
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| 214 | if (mEnforceBounds && Bounds != null) {
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[2768] | 215 |
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[4068] | 216 | double hw = item.Rectangle.Width / 2;
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| 217 | double hh = item.Rectangle.Height / 2;
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| 218 | if (x + hw > x2) x = x2 - hw;
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| 219 | if (x - hw < x1) x = x1 + hw;
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| 220 | if (y + hh > y2) y = y2 - hh;
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| 221 | if (y - hh < y1) y = y1 + hh;
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[2768] | 222 | }
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| 223 |
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[4068] | 224 | // set the actual position
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| 225 | setX(item, referrer, x);
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| 226 | setY(item, referrer, y);
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| 227 | }
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| 228 | }
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| 229 |
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| 230 | ///<summary>
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| 231 | /// Reset the force simulation state for all nodes processed by this layout.
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| 232 | ///</summary>
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| 233 | public void Reset() {
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| 234 | foreach (INode item in Nodes) {
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| 235 | ForceItem fitem = Pars[item.Uid.ToString()];
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| 236 | if (fitem != null) {
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| 237 | fitem.Location[0] = (float)item.X;
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| 238 | fitem.Location[1] = (float)item.Y;
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| 239 | fitem.Force[0] = fitem.Force[1] = 0;
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| 240 | fitem.Velocity[0] = fitem.Velocity[1] = 0;
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[2768] | 241 | }
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[4068] | 242 | }
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| 243 | m_lasttime = -1L;
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| 244 | }
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[2768] | 245 |
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[4068] | 246 | /// <summary>
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| 247 | /// Loads the simulator with all relevant force items and springs.
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| 248 | /// </summary>
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| 249 | /// <param name="fsim"> the force simulator driving this layout.</param>
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| 250 | protected void InitializeSimulator(ForceSimulator fsim) {
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| 251 | //TODO: some checks here...?
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[2768] | 252 |
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[4068] | 253 | float startX = (referrer == null ? 0f : (float)referrer.X);
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| 254 | float startY = (referrer == null ? 0f : (float)referrer.Y);
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| 255 | startX = float.IsNaN(startX) ? 0f : startX;
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| 256 | startY = float.IsNaN(startY) ? 0f : startY;
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| 257 | if (Nodes != null && Nodes.Count > 0) {
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| 258 | foreach (INode item in Nodes) {
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| 259 | ForceItem fitem = Pars[item.Uid.ToString()];
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| 260 | fitem.Mass = getMassValue(item);
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| 261 | double x = item.X;
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| 262 | double y = item.Y;
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| 263 | fitem.Location[0] = (Double.IsNaN(x) ? startX : (float)x);
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| 264 | fitem.Location[1] = (Double.IsNaN(y) ? startY : (float)y);
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| 265 | fsim.addItem(fitem);
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[2768] | 266 | }
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[4068] | 267 | }
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| 268 | if (Edges != null && Edges.Count > 0) {
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| 269 | foreach (IEdge e in Edges) {
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| 270 | INode n1 = e.SourceNode;
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| 271 | if (n1 == null) continue;
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| 272 | ForceItem f1 = Pars[n1.Uid.ToString()];
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| 273 | INode n2 = e.TargetNode;
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| 274 | if (n2 == null) continue;
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| 275 | ForceItem f2 = Pars[n2.Uid.ToString()];
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| 276 | float coeff = getSpringCoefficient(e);
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| 277 | float slen = getSpringLength(e);
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| 278 | fsim.addSpring(f1, f2, (coeff >= 0 ? coeff : -1.0F), (slen >= 0 ? slen : -1.0F));
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| 279 | }
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| 280 | }
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| 281 | }
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| 282 | private void Layout() {
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| 283 | // perform different actions if this is a run-once or
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| 284 | // run-continuously layout
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| 285 | if (m_runonce) {
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| 286 | PointF anchor = new PointF(Bounds.Width / 2F, Bounds.Height / 2F);
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| 287 | foreach (INode node in Nodes) {
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| 288 | setX(node, null, anchor.X);
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| 289 | setY(node, null, anchor.Y);
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| 290 | }
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| 291 | m_fsim.Clear();
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| 292 | long timestep = 1000L;
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[2768] | 293 |
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[4068] | 294 | InitializeSimulator(m_fsim);
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[2768] | 295 |
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[4068] | 296 | for (int i = 0; i < m_iterations; i++) {
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| 297 | // use an annealing schedule to set time step
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| 298 | timestep *= Convert.ToInt64(1.0 - i / (double)m_iterations);
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| 299 | long step = timestep + 50;
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| 300 | // run simulator
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| 301 | m_fsim.RunSimulator(step);
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| 302 | // debugging output
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| 303 | //if (i % 10 == 0 ) {Trace.WriteLine("iter: "+i);}
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[2768] | 304 | }
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[4068] | 305 | UpdateNodePositions();
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| 306 | } else {
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| 307 | // get timestep
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| 308 | if (m_lasttime == -1)
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| 309 | m_lasttime = DateTime.Now.Ticks * 10 - 20;
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| 310 | long time = DateTime.Now.Ticks * 10;//how many milliseconds since the human race started to count things
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| 311 | long timestep = Math.Min(m_maxstep, time - m_lasttime);
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| 312 | m_lasttime = time;
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[2768] | 313 |
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[4068] | 314 | // run force simulator
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| 315 | m_fsim.Clear();
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| 316 | InitializeSimulator(m_fsim);
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| 317 | m_fsim.RunSimulator(timestep);
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| 318 | UpdateNodePositions();
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| 319 | }
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| 320 | //if ( frac == 1.0 ) {
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| 321 | // reset();
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| 322 | //}
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[2768] | 323 | }
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[4068] | 324 | #endregion
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| 325 |
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| 326 | }
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[2768] | 327 | }
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