Merge branch 'coloring' into 'master'

Rework the algorithm that chooses colors for DOT output

See merge request !28

src/SparseTransform.CLI/Program.cs

@@ -71,7 +71,7 @@ public class Program
     /// <returns>Dot String with coloring information</returns>
     private static String Partition2ColoredDot(String MMMatrix, bool textColor = false)
     {
-        return ConversionManager.Partition2ColoredDot(MMMatrix);
+        return ConversionManager.Partition2ColoredDot(MMMatrix, textColor);
     }
 
     /// <summary>

src/SparseTransform/ConversionManager.cs

@@ -26,7 +26,7 @@ namespace SparseTransform
         /// <param name="MMMatrix">raw MatrixMarket input String</param> 
         /// <param name="textColor">true if color should additionally be represented as text</param>
         /// <returns>Dot String with coloring information</returns>
-        public static String Partition2ColoredDot(String MMMatrix, bool textColor= false)
+        public static String Partition2ColoredDot(String MMMatrix, bool textColor = false)
         {
             MatrixMarketReader reader = new MatrixMarketReader();
             IGraph graph = reader.ReadGraph(MMMatrix);
@@ -40,7 +40,7 @@ namespace SparseTransform
             }
             else
                 color.PartialD2Color((BipartiteGraph)graph);
-            ColoredDotWriter writer = new ColoredDotWriter(textColor);
+            ColoredDotWriter writer = new ColoredDotWriter(graph, textColor);
             return writer.Write(graph);
 
         }

src/SparseTransform/Convert/ColoredDotWriter.cs

 using SparseTransform.DataStructures;
+using System.Text;
 
 namespace SparseTransform.Convert
 {
@@ -7,27 +8,17 @@ namespace SparseTransform.Convert
     /// </summary>
     public class ColoredDotWriter : DotWriter
     {
-        private bool textcolor;
-        private string[] dictColor = new string[65];
+        private IGraph _coloredGraph;
+        private bool _textcolor;
        
         /// <summary>
         /// Constructor constructing a color-dictionary for coloring purpose.
         /// </summary>
         /// <param name="textColor">decision whether the labels should be colored or labelled.</param>
-        public ColoredDotWriter(bool textColor)
+        public ColoredDotWriter(IGraph graph, bool textColor)
         {
-            this.textcolor = textColor;
-
-            for (int i = 0; i <= 3; i++)
-            {
-                for (int j = 0; j <= 3; j++)
-                {
-                    for (int k = 0; k <= 4; k++)
-                    {
-                        dictColor[i * 16 + j * 4 + k] = ("#" + (255 - i * 60).ToString("X2") + (255 - j * 60).ToString("X2") + (255 - k * 60).ToString("X2"));
-                    }
-                }
-            }
+            this._coloredGraph = graph;
+            this._textcolor = textColor;
         }
        
         /// <summary>
@@ -38,14 +29,32 @@ namespace SparseTransform.Convert
         /// <returns></returns>
         public override String NodeLabel(GraphNode node, String prefix)
         {
-            if (textcolor || node.Color > 64)
-            {
-                return "\t" + prefix + node.Index + "  [shape=circle, style=filled, label=\"" + prefix + node.Index + "\\n Farbe " + node.Color + "\"]";
-            }
-            else
+            // This is the offset. Less colors = more distance between
+            int hueFactor = 255 / _coloredGraph.ColorsUsed;
+            // Calculate the hue. We modulo with 255 to not exceed spectrum. Then convert to float for DOT
+            double hue = Math.Round((double)((node.Color * hueFactor) % 255) / 255, 3);
+
+            StringBuilder label = new StringBuilder();
+            // Append label name and general layout info
+            label.Append($"\t{prefix}{node.Index} [shape=circle, style=filled");
+
+            // If current node is colored, apply either text label with color or set fill color
+            if (node.Colored)
             {
-                return "\t" + prefix + node.Index + "  [shape=circle, style=filled, fillcolor=\"" + dictColor[node.Color] + "\"]";
+                if (_textcolor || _coloredGraph.ColorsUsed > 255)
+                {
+                    label.Append($", label=\"{prefix}{node.Index}\\n color:{node.Color}\"");
+                }
+                else
+                {
+                    // Set saturation + value (brightness) to max for vibrant colors
+                    label.Append($", fillcolor=\"{hue} {1} {1}\"");
+                }
             }
+
+            // Close attribute line
+            label.Append("]");
+            return label.ToString();
         }
     }
 }

src/SparseTransform/DataStructures/AdjacencyGraph.cs

@@ -37,7 +37,7 @@ namespace SparseTransform.DataStructures
         /// <summary>
         /// Number of colors used for coloring.
         /// </summary>
-        private int ColorsUsed
+        public int ColorsUsed
         {
             get
             {

src/SparseTransform/DataStructures/BipartiteGraph.cs

@@ -69,7 +69,7 @@ namespace SparseTransform.DataStructures
         /// <summary>
         /// Number of colors used for coloring. Works if either or both sides are colored
         /// </summary>
-        private int ColorsUsed
+        public int ColorsUsed
         {
             get
             {

src/SparseTransform/DataStructures/IGraph.cs

@@ -6,6 +6,8 @@ namespace SparseTransform.DataStructures
     /// </summary>
     public interface IGraph
     {
+        public int ColorsUsed { get; }
+
         /// <summary>
         /// Adds an edge between nodes i and j. If either of the nodes is missing it is created.
         /// </summary>