Refactored brushes, gradients, effects and the keyboard to uncouple them

Gradients/AbstractGradient.cs

@@ -0,0 +1,72 @@
+// ReSharper disable MemberCanBeProtected.Global
+
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+
+namespace CUE.NET.Gradients
+{
+    /// <summary>
+    /// Represents a basic gradient.
+    /// </summary>
+    public abstract class AbstractGradient : IGradient
+    {
+        #region Properties & Fields
+
+        /// <summary>
+        /// Gets a list of the stops used by this gradient.
+        /// </summary>
+        public IList<GradientStop> GradientStops { get; } = new List<GradientStop>();
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AbstractGradient"/> class.
+        /// </summary>
+        protected AbstractGradient()
+        { }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="AbstractGradient"/> class.
+        /// </summary>
+        /// <param name="gradientStops">The stops with which the gradient should be initialized.</param>
+        protected AbstractGradient(params GradientStop[] gradientStops)
+        {
+            foreach (GradientStop gradientStop in gradientStops)
+                GradientStops.Add(gradientStop);
+        }
+
+        #endregion
+
+        #region Methods
+
+        /// <summary>
+        /// Clips the offset and ensures, that it is inside the bounds of the stop list.
+        /// </summary>
+        /// <param name="offset"></param>
+        /// <returns></returns>
+        protected float ClipOffset(float offset)
+        {
+            float max = GradientStops.Max(n => n.Offset);
+            if (offset > max)
+                return max;
+
+            float min = GradientStops.Min(n => n.Offset);
+            if (offset < min)
+                return min;
+
+            return offset;
+        }
+
+        /// <summary>
+        /// Gets the color of the gradient on the specified offset.
+        /// </summary>
+        /// <param name="offset">The percentage offset to take the color from.</param>
+        /// <returns>The color at the specific offset.</returns>
+        public abstract Color GetColor(float offset);
+
+        #endregion
+    }
+}

Gradients/GradientStop.cs

@@ -0,0 +1,42 @@
+// ReSharper disable AutoPropertyCanBeMadeGetOnly.Global
+// ReSharper disable MemberCanBePrivate.Global
+
+using System.Drawing;
+
+namespace CUE.NET.Gradients
+{
+    /// <summary>
+    /// Represents a stop on a gradient.
+    /// </summary>
+    public class GradientStop
+    {
+        #region Properties & Fields
+
+        /// <summary>
+        /// Gets or sets the percentage offset to place this stop. This should be inside the range of [0..1] but it's not necessary.
+        /// </summary>
+        public float Offset { get; set; }
+
+        /// <summary>
+        /// Gets or sets the color of the stop.
+        /// </summary>
+        public Color Color { get; set; }
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="GradientStop"/> class.
+        /// </summary>
+        /// <param name="offset">The percentage offset to place this stop.</param>
+        /// <param name="color">The color of the stop.</param>
+        public GradientStop(float offset, Color color)
+        {
+            this.Offset = offset;
+            this.Color = color;
+        }
+
+        #endregion
+    }
+}

Gradients/IGradient.cs

@@ -0,0 +1,17 @@
+using System.Drawing;
+
+namespace CUE.NET.Gradients
+{
+    /// <summary>
+    /// Represents a basic gradient.
+    /// </summary>
+    public interface IGradient
+    {
+        /// <summary>
+        /// Gets the color of the gradient on the specified offset.
+        /// </summary>
+        /// <param name="offset">The percentage offset to take the color from.</param>
+        /// <returns>The color at the specific offset.</returns>
+        Color GetColor(float offset);
+    }
+}

Gradients/LinearGradient.cs

@@ -0,0 +1,60 @@
+using System.Drawing;
+using System.Linq;
+
+namespace CUE.NET.Gradients
+{
+    /// <summary>
+    /// Represents a linear interpolated gradient with n stops.
+    /// </summary>
+    public class LinearGradient : AbstractGradient
+    {
+        #region Constructors
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="LinearGradient"/> class.
+        /// </summary>
+        public LinearGradient()
+        { }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="LinearGradient"/> class.
+        /// </summary>
+        /// <param name="gradientStops">The stops with which the gradient should be initialized.</param>
+        public LinearGradient(params GradientStop[] gradientStops)
+            : base(gradientStops)
+        { }
+
+        #endregion
+
+        #region Methods
+
+        /// <summary>
+        /// Gets the linear interpolated color at the given offset.
+        /// </summary>
+        /// <param name="offset">The percentage offset to take the color from.</param>
+        /// <returns>The color at the specific offset.</returns>
+        public override Color GetColor(float offset)
+        {
+            if (!GradientStops.Any()) return Color.Transparent;
+            if (GradientStops.Count == 1) return GradientStops.First().Color;
+
+            offset = ClipOffset(offset);
+
+            GradientStop gsBefore = GradientStops.Where(n => n.Offset <= offset).OrderBy(n => n.Offset).Last();
+            GradientStop gsAfter = GradientStops.Where(n => n.Offset >= offset).OrderBy(n => n.Offset).First();
+
+            float blendFactor = 0f;
+            if (!gsBefore.Offset.Equals(gsAfter.Offset))
+                blendFactor = ((offset - gsBefore.Offset) / (gsAfter.Offset - gsBefore.Offset));
+
+            byte colA = (byte)((gsAfter.Color.A - gsBefore.Color.A) * blendFactor + gsBefore.Color.A);
+            byte colR = (byte)((gsAfter.Color.R - gsBefore.Color.R) * blendFactor + gsBefore.Color.R);
+            byte colG = (byte)((gsAfter.Color.G - gsBefore.Color.G) * blendFactor + gsBefore.Color.G);
+            byte colB = (byte)((gsAfter.Color.B - gsBefore.Color.B) * blendFactor + gsBefore.Color.B);
+
+            return Color.FromArgb(colA, colR, colG, colB);
+        }
+
+        #endregion
+    }
+}

Gradients/RainbowGradient.cs

@@ -0,0 +1,61 @@
+// ReSharper disable MemberCanBePrivate.Global
+
+using System.Drawing;
+using CUE.NET.Helper;
+
+namespace CUE.NET.Gradients
+{
+    /// <summary>
+    /// Represents a rainbow gradient which circles through all color colors of the HUE-color-space.<br />
+    /// See <see cref="http://upload.wikimedia.org/wikipedia/commons/a/ad/HueScale.svg" /> as reference
+    /// </summary>
+    public class RainbowGradient : IGradient
+    {
+        #region Properties & Fields
+
+        /// <summary>
+        /// Gets or sets the hue (in degrees) to start from.
+        /// </summary>
+        public float StartHue { get; set; }
+
+        /// <summary>
+        /// Gets or sets the hue (in degrees) to end the with.
+        /// </summary>
+        public float EndHue { get; set; }
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RainbowGradient"/> class.
+        /// </summary>
+        /// <param name="startHue">The hue (in degrees) to start from (default: 0)</param>
+        /// <param name="endHue">The hue (in degrees) to end with (default: 360)</param>
+        public RainbowGradient(float startHue = 0f, float endHue = 360f)
+        {
+            this.StartHue = startHue;
+            this.EndHue = endHue;
+        }
+
+        #endregion
+
+        #region Methods
+
+        #endregion
+
+        /// <summary>
+        /// Gets the color on the rainbow at the given offset.
+        /// </summary>
+        /// <param name="offset">The percentage offset to take the color from.</param>
+        /// <returns>The color at the specific offset.</returns>
+        public Color GetColor(float offset)
+        {
+            float range = EndHue - StartHue;
+            float hue = (StartHue + (range * offset)) % 360f;
+            if (hue < 0)
+                hue += 360;
+            return ColorHelper.ColorFromHSV(hue, 1f, 1f);
+        }
+    }
+}