Implemented translations properly on top of the layer shape

src/Artemis.UI/Services/LayerShapeService.cs

@@ -0,0 +1,116 @@
+using System;
+using System.Linq;
+using System.Windows;
+using System.Windows.Media;
+using Artemis.Core.Models.Profile;
+using Artemis.Core.Models.Profile.LayerShapes;
+using Artemis.Core.Services;
+using Artemis.UI.Services.Interfaces;
+using SkiaSharp;
+using SkiaSharp.Views.WPF;
+
+namespace Artemis.UI.Services
+{
+    public class LayerEditorService : ILayerEditorService
+    {
+        private readonly ISettingsService _settingsService;
+
+        public LayerEditorService(ISettingsService settingsService)
+        {
+            _settingsService = settingsService;
+        }
+
+        /// <inheritdoc />
+        public Rect GetShapeRenderRect(LayerShape layerShape)
+        {
+            // Adjust the render rectangle for the difference in render scale
+            var renderScale = _settingsService.GetSetting("Core.RenderScale", 1.0).Value;
+            return new Rect(
+                layerShape.RenderRectangle.Left / renderScale * 1,
+                layerShape.RenderRectangle.Top / renderScale * 1,
+                Math.Max(0, layerShape.RenderRectangle.Width / renderScale * 1),
+                Math.Max(0, layerShape.RenderRectangle.Height / renderScale * 1)
+            );
+        }
+
+        public Rect GetLayerRenderRect(Layer layer)
+        {
+            // Adjust the render rectangle for the difference in render scale
+            var renderScale = _settingsService.GetSetting("Core.RenderScale", 1.0).Value;
+            return new Rect(
+                layer.AbsoluteRectangle.Left / renderScale * 1,
+                layer.AbsoluteRectangle.Top / renderScale * 1,
+                Math.Max(0, layer.AbsoluteRectangle.Width / renderScale * 1),
+                Math.Max(0, layer.AbsoluteRectangle.Height / renderScale * 1)
+            );
+        }
+
+        /// <inheritdoc />
+        public void SetShapeRenderRect(LayerShape layerShape, Rect rect)
+        {
+            if (!layerShape.Layer.Leds.Any())
+            {
+                layerShape.ScaledRectangle = SKRect.Empty;
+                return;
+            }
+
+            // Adjust the provided rect for the difference in render scale
+            var renderScale = _settingsService.GetSetting("Core.RenderScale", 1.0).Value;
+            layerShape.ScaledRectangle = SKRect.Create(
+                100f / layerShape.Layer.AbsoluteRectangle.Width * ((float) (rect.Left * renderScale) - layerShape.Layer.AbsoluteRectangle.Left) / 100f,
+                100f / layerShape.Layer.AbsoluteRectangle.Height * ((float) (rect.Top * renderScale) - layerShape.Layer.AbsoluteRectangle.Top) / 100f,
+                100f / layerShape.Layer.AbsoluteRectangle.Width * (float) (rect.Width * renderScale) / 100f,
+                100f / layerShape.Layer.AbsoluteRectangle.Height * (float) (rect.Height * renderScale) / 100f
+            );
+            layerShape.CalculateRenderProperties();
+        }
+
+        /// <inheritdoc />
+        public TransformGroup GetLayerTransformGroup(Layer layer)
+        {
+            var layerRect = GetLayerRenderRect(layer).ToSKRect();
+            var shapeRect = GetShapeRenderRect(layer.LayerShape).ToSKRect();
+
+            // Apply transformation like done by the core during layer rendering
+            var anchor = layer.AnchorPointProperty.CurrentValue;
+            var position = layer.PositionProperty.CurrentValue;
+            var size = layer.SizeProperty.CurrentValue;
+            var rotation = layer.RotationProperty.CurrentValue;
+            // Scale the anchor and make it originate from the center of the untranslated layer shape
+            anchor.X = anchor.X * layerRect.Width + shapeRect.MidX;
+            anchor.Y = anchor.Y * layerRect.Height + shapeRect.MidY;
+            
+            var transformGroup = new TransformGroup();
+            transformGroup.Children.Add(new ScaleTransform(size.Width, size.Height, anchor.X, anchor.Y));
+            transformGroup.Children.Add(new RotateTransform(rotation, anchor.X, anchor.Y));
+            transformGroup.Children.Add(new TranslateTransform(position.X * layerRect.Width, position.Y * layerRect.Height));
+
+            return transformGroup;
+        }
+    }
+
+    public interface ILayerEditorService : IArtemisUIService
+    {
+        /// <summary>
+        ///     Returns an absolute and scaled rectangle for the given shape that is corrected for the current render scale.
+        /// </summary>
+        /// <returns></returns>
+        Rect GetShapeRenderRect(LayerShape layerShape);
+
+        /// <summary>
+        ///     Sets the render rectangle of the given shape to match the provided unscaled rectangle. The rectangle is corrected
+        ///     for the current render scale.
+        /// </summary>
+        /// <param name="layerShape"></param>
+        /// <param name="rect"></param>
+        void SetShapeRenderRect(LayerShape layerShape, Rect rect);
+
+        /// <summary>
+        /// Creates a WPF transform group that contains all the transformations required to render the provided layer.
+        /// Note: Run on UI thread.
+        /// </summary>
+        /// <param name="layer"></param>
+        /// <returns></returns>
+        TransformGroup GetLayerTransformGroup(Layer layer);
+    }
+}