Added LinearGradientBrush, improved example

Devices/Keyboard/Brushes/GradientStop.cs

@@ -0,0 +1,26 @@
+using System.Drawing;
+
+namespace CUE.NET.Devices.Keyboard.Brushes
+{
+    public class GradientStop
+    {
+
+        #region Properties & Fields
+
+        public float Offset { get; set; }
+
+        public Color Color { get; set; }
+
+        #endregion
+
+        #region Constructors
+
+        public GradientStop(float offset, Color color)
+        {
+            this.Offset = offset;
+            this.Color = color;
+        }
+
+        #endregion
+    }
+}

Devices/Keyboard/Brushes/IBrush.cs

@@ -1,6 +1,6 @@
 using System.Drawing;
 
-namespace CUE.NET.Devices.Keyboard.ColorBrushes
+namespace CUE.NET.Devices.Keyboard.Brushes
 {
     public interface IBrush
     {

Devices/Keyboard/Brushes/LinearGradientBrush.cs

@@ -0,0 +1,132 @@
+// ReSharper disable CollectionNeverUpdated.Global
+// ReSharper disable MemberCanBePrivate.Global
+// ReSharper disable ReturnTypeCanBeEnumerable.Global
+
+using System;
+using System.Collections.Generic;
+using System.Drawing;
+using System.Linq;
+
+namespace CUE.NET.Devices.Keyboard.Brushes
+{
+    public class LinearGradientBrush : IBrush
+    {
+        #region Properties & Fields
+
+        public PointF StartPoint { get; set; } = new PointF(0f, 0.5f);
+        public PointF EndPoint { get; set; } = new PointF(1f, 0.5f);
+        public IList<GradientStop> GradientStops { get; } = new List<GradientStop>();
+
+        #endregion
+
+        #region Constructor
+
+        public LinearGradientBrush()
+        { }
+
+        public LinearGradientBrush(PointF startPoint, PointF endPoint, params GradientStop[] gradientStops)
+        {
+            this.StartPoint = startPoint;
+            this.EndPoint = endPoint;
+
+            foreach (GradientStop gradientStop in gradientStops)
+                GradientStops.Add(gradientStop);
+        }
+
+        public LinearGradientBrush(params GradientStop[] gradientStops)
+        {
+            foreach (GradientStop gradientStop in gradientStops)
+                GradientStops.Add(gradientStop);
+        }
+
+        #endregion
+
+        #region Methods
+        
+        public Color GetColorAtPoint(RectangleF rectangle, PointF point)
+        {
+            if (!GradientStops.Any()) return Color.Transparent;
+            if (GradientStops.Count == 1) return GradientStops.First().Color;
+
+            // Taken from https://dotupdate.wordpress.com/2008/01/28/find-the-color-of-a-point-in-a-lineargradientbrush/
+
+            float x3 = point.X;
+            float y3 = point.Y;
+
+            float x1 = StartPoint.X * rectangle.Width;
+            float y1 = StartPoint.Y * rectangle.Height;
+            PointF p1 = new PointF(x1, y1); // Starting point
+
+            float x2 = EndPoint.X * rectangle.Width;
+            float y2 = EndPoint.Y * rectangle.Height;
+            PointF p2 = new PointF(x2, y2);  //End point
+
+            // Calculate intersecting points 
+            PointF p4;
+
+            if (y1.Equals(y2)) // Horizontal case
+                p4 = new PointF(x3, y1);
+
+            else if (x1.Equals(x2)) // Vertical case
+                p4 = new PointF(x1, y3);
+
+            else // Diagnonal case
+            {
+                float m = (y2 - y1) / (x2 - x1);
+                float m2 = -1 / m;
+                float b = y1 - m * x1;
+                float c = y3 - m2 * x3;
+
+                float x4 = (c - b) / (m - m2);
+                float y4 = m * x4 + b;
+                p4 = new PointF(x4, y4);
+            }
+
+            // Calculate distances relative to the vector start
+            float d4 = Dist(p4, p1, p2);
+            float d2 = Dist(p2, p1, p2);
+
+            float x = d4 / d2;
+
+            // Clip the input if before or after the max/min offset values
+            float max = GradientStops.Max(n => n.Offset);
+            if (x > max)
+                x = max;
+
+            float min = GradientStops.Min(n => n.Offset);
+            if (x < min)
+                x = min;
+
+            // Find gradient stops that surround the input value
+            GradientStop gs0 = GradientStops.Where(n => n.Offset <= x).OrderBy(n => n.Offset).Last();
+            GradientStop gs1 = GradientStops.Where(n => n.Offset >= x).OrderBy(n => n.Offset).First();
+
+            float y = 0f;
+            if (!gs0.Offset.Equals(gs1.Offset))
+                y = ((x - gs0.Offset) / (gs1.Offset - gs0.Offset));
+
+            byte colA = (byte)((gs1.Color.A - gs0.Color.A) * y + gs0.Color.A);
+            byte colR = (byte)((gs1.Color.R - gs0.Color.R) * y + gs0.Color.R);
+            byte colG = (byte)((gs1.Color.G - gs0.Color.G) * y + gs0.Color.G);
+            byte colB = (byte)((gs1.Color.B - gs0.Color.B) * y + gs0.Color.B);
+            return Color.FromArgb(colA, colR, colG, colB);
+        }
+
+        // Taken from https://dotupdate.wordpress.com/2008/01/28/find-the-color-of-a-point-in-a-lineargradientbrush/
+        /// <summary>
+        /// Returns the signed magnitude of a point on a vector with origin po and pointing to pf
+        /// </summary>
+        private float Dist(PointF px, PointF po, PointF pf)
+        {
+            float d = (float)Math.Sqrt((px.Y - po.Y) * (px.Y - po.Y) + (px.X - po.X) * (px.X - po.X));
+
+            return (((px.Y < po.Y) && (pf.Y > po.Y)) ||
+                ((px.Y > po.Y) && (pf.Y < po.Y)) ||
+                ((px.Y.Equals(po.Y)) && (px.X < po.X) && (pf.X > po.X)) ||
+                ((px.Y.Equals(po.Y)) && (px.X > po.X) && (pf.X < po.X)))
+                ? -d : d;
+        }
+
+        #endregion
+    }
+}

Devices/Keyboard/Brushes/SolidColorBrush.cs

@@ -1,6 +1,6 @@
 using System.Drawing;
 
-namespace CUE.NET.Devices.Keyboard.ColorBrushes
+namespace CUE.NET.Devices.Keyboard.Brushes
 {
     public class SolidColorBrush : IBrush
     {

Devices/Keyboard/CorsairKeyboard.cs

@@ -6,7 +6,7 @@ using System.Drawing;
 using System.Linq;
 using System.Runtime.InteropServices;
 using CUE.NET.Devices.Generic;
-using CUE.NET.Devices.Keyboard.ColorBrushes;
+using CUE.NET.Devices.Keyboard.Brushes;
 using CUE.NET.Devices.Keyboard.Enums;
 using CUE.NET.Devices.Keyboard.Keys;
 using CUE.NET.Helper;

Devices/Keyboard/Keys/BaseKeyGroup.cs

@@ -1,6 +1,6 @@
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using CUE.NET.Devices.Keyboard.ColorBrushes;
+using CUE.NET.Devices.Keyboard.Brushes;
 using CUE.NET.Devices.Keyboard.Extensions;
 
 namespace CUE.NET.Devices.Keyboard.Keys

Devices/Keyboard/Keys/IKeyGroup.cs

@@ -1,5 +1,5 @@
 using System.Collections.Generic;
-using CUE.NET.Devices.Keyboard.ColorBrushes;
+using CUE.NET.Devices.Keyboard.Brushes;
 
 namespace CUE.NET.Devices.Keyboard.Keys
 {