Added some test animations

src/Artemis.Plugins.LayerElements.Animations/RotationLayerElement.cs

@@ -0,0 +1,36 @@
+using Artemis.Core.Models.Profile;
+using Artemis.Core.Models.Surface;
+using Artemis.Core.Plugins.LayerElement;
+using SkiaSharp;
+
+namespace Artemis.Plugins.LayerElements.Animations
+{
+    public class RotationLayerElement : LayerElement
+    {
+        public RotationLayerElement(Layer layer, LayerElementSettings settings, LayerElementDescriptor descriptor) : base(layer, settings, descriptor)
+        {
+        }
+
+        public float Rotation { get; set; }
+
+        public override LayerElementViewModel GetViewModel()
+        {
+            return null;
+        }
+
+        public override void Update(double deltaTime)
+        {
+            Rotation += (float)(deltaTime * 100);
+            if (Rotation > 360)
+                Rotation = 0;
+        }
+
+        public override SKShader RenderPostProcess(ArtemisSurface surface, SKBitmap bitmap, SKShader shader)
+        {
+            var center = new SKPoint(Layer.AbsoluteRenderRectangle.MidX, Layer.AbsoluteRenderRectangle.MidY);
+
+            // TODO Scale so that the rectangle is covered in every rotation, instead of just putting it at 2
+            return SKShader.CreateLocalMatrix(SKShader.CreateLocalMatrix(shader, SKMatrix.MakeScale(2, 2, center.X, center.Y)), SKMatrix.MakeRotationDegrees(Rotation, center.X, center.Y));
+        }
+    }
+}