support getting colormaps by their name

#18

Author: swharden

src/Spectrogram.Tests/ColormapExamples.cs

@@ -32,5 +32,15 @@ public void Test_Make_CommonColormaps()
  Debug.WriteLine($"![](dev/graphics/hal-{cmap.Name}.png)");
  }
  }
+
+ [Test]
+ public void Test_Colormaps_ByName()
+ {
+ string[] names = Colormap.GetColormapNames();
+ Console.WriteLine(string.Join(", ", names));
+
+ Colormap viridisCmap = Colormap.GetColormap("viridis");
+ Assert.AreEqual("Viridis", viridisCmap.Name);
+ }
  }
 }

src/Spectrogram/Colormap.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.ComponentModel;
 using System.Drawing;
 using System.Linq;
 using System.Text;
@@ -46,6 +47,20 @@ public static Colormap[] GetColormaps()
  return ics.Select(x => new Colormap(x)).ToArray();
  }
 
+ public static string[] GetColormapNames()
+ {
+ return GetColormaps().Select(x => x.Name).ToArray();
+ }
+
+ public static Colormap GetColormap(string colormapName)
+ {
+ foreach (Colormap cmap in GetColormaps())
+ if (string.Equals(cmap.Name, colormapName, StringComparison.InvariantCultureIgnoreCase))
+ return cmap;
+
+ throw new ArgumentException($"Colormap does not exist: {colormapName}");
+ }
+
  public (byte r, byte g, byte b) GetRGB(byte value)
  {
  return cmap.GetRGB(value);