Updated Implementing an own brush (markdown)

Implementing-an-own-brush.md

@@ -22,6 +22,20 @@ public class SolidColorBrush : AbstractBrush
 ```
 
 As you can see the _[SolidColorBrush](https://github.com/DarthAffe/CUE.NET/blob/master/Brushes/SolidColorBrush.cs)_ doesn't care about what key or rectangle is rendered and therefore just ignores the passed parameters.   
-In most cases we want to draw something though, so we need to calculate our color from the given information. A good example here is the _[LinearGradientBrush](https://github.com/DarthAffe/CUE.NET/blob/master/Brushes/LinearGradientBrush.cs)_
+In most cases we want to draw something though, so we need to calculate our color from the given information. A good example here is the _[LinearGradientBrush](https://github.com/DarthAffe/CUE.NET/blob/master/Brushes/LinearGradientBrush.cs)_.
+```c#
+protected override CorsairColor GetColorAtPoint(RectangleF rectangle, BrushRenderTarget renderTarget)
+{
+    if (Gradient == null) return CorsairColor.Transparent;
+
+    PointF startPoint = new PointF(StartPoint.X * rectangle.Width, StartPoint.Y * rectangle.Height);
+    PointF endPoint = new PointF(EndPoint.X * rectangle.Width, EndPoint.Y * rectangle.Height);
+    
+    float offset = GradientHelper.CalculateLinearGradientOffset(startPoint, endPoint, renderTarget.Point); 
+    return Gradient.GetColor(offset);
+}
+```
+First it uses the size of the provided rectangle to calculate a start- and end-point for the gradient. After wards it using the Point (which reflects the center of the requested key) provided by the _[renderTarget](https://github.com/DarthAffe/CUE.NET/blob/master/Brushes/BrushRenderTarget.cs)_ to calculate the offset which is finally used to return the color on the gradient.   
+Note that you can not only get the point of the _[renderTarget](https://github.com/DarthAffe/CUE.NET/blob/master/Brushes/BrushRenderTarget.cs)_ but also the whole rectangle representing the key and the Id of the key.
 
 ### The advanced way