Initial Commit

Common/Palettes/LinearPalette.cs

@@ -0,0 +1,99 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Windows.Media;
+using System.Diagnostics;
+
+namespace Microsoft.Research.DynamicDataDisplay.Common.Palettes
+{
+	/// <summary>
+	/// Represents a color step with its offset in limits [0..1].
+	/// </summary>
+	[DebuggerDisplay("Color={Color}, Offset={Offset}")]
+	public class LinearPaletteColorStep
+	{
+		/// <summary>
+		/// Initializes a new instance of the <see cref="LinearPaletteColorStep"/> class.
+		/// </summary>
+		public LinearPaletteColorStep() { }
+		/// <summary>
+		/// Initializes a new instance of the <see cref="LinearPaletteColorStep"/> class.
+		/// </summary>
+		/// <param name="color">The color.</param>
+		/// <param name="offset">The offset.</param>
+		public LinearPaletteColorStep(Color color, double offset)
+		{
+			this.Color = color;
+			this.Offset = offset;
+		}
+
+		/// <summary>
+		/// Gets or sets the color.
+		/// </summary>
+		/// <value>The color.</value>
+		public Color Color { get; set; }
+		/// <summary>
+		/// Gets or sets the offset.
+		/// </summary>
+		/// <value>The offset.</value>
+		public double Offset { get; set; }
+	}
+
+	/// <summary>
+	/// Represents a palette with start and stop colors and intermediate colors with their custom offsets.
+	/// </summary>
+	public class LinearPalette : IPalette
+	{
+		/// <summary>
+		/// Initializes a new instance of the <see cref="LinearPalette"/> class.
+		/// </summary>
+		/// <param name="startColor">The start color.</param>
+		/// <param name="endColor">The end color.</param>
+		/// <param name="steps">The steps.</param>
+		public LinearPalette(Color startColor, Color endColor, params LinearPaletteColorStep[] steps)
+		{
+			this.steps.Add(new LinearPaletteColorStep(startColor, 0));
+			if (steps != null)
+				this.steps.AddMany(steps);
+			this.steps.Add(new LinearPaletteColorStep(endColor, 1));
+		}
+
+		private readonly List<LinearPaletteColorStep> steps = new List<LinearPaletteColorStep>();
+
+		#region IPalette Members
+
+		/// <summary>
+		/// Gets the color by interpolation coefficient.
+		/// </summary>
+		/// <param name="t">Interpolation coefficient, should belong to [0..1].</param>
+		/// <returns>Color.</returns>
+		public Color GetColor(double t)
+		{
+			if (t < 0) return steps[0].Color;
+			if (t > 1) return steps[steps.Count - 1].Color;
+
+			int i = 0;
+			double x = 0;
+			while (x <= t)
+			{
+				x = steps[i + 1].Offset;
+				i++;
+			}
+
+			Color c0 = steps[i - 1].Color;
+			Color c1 = steps[i].Color;
+			double ratio = (t - steps[i - 1].Offset) / (steps[i].Offset - steps[i - 1].Offset);
+
+			Color result = Color.FromRgb(
+				(byte)((1 - ratio) * c0.R + ratio * c1.R),
+				(byte)((1 - ratio) * c0.G + ratio * c1.G),
+				(byte)((1 - ratio) * c0.B + ratio * c1.B));
+			return result;
+		}
+#pragma warning disable 0067
+		public event EventHandler Changed;
+#pragma warning restore 0067
+		#endregion
+	}
+}