Show outlines for all layers

Rotation fixes
Movement fixes

src/Artemis.UI/Services/Interfaces/ILayerEditorService.cs

@@ -18,8 +18,9 @@ namespace Artemis.UI.Services.Interfaces
         ///     Returns the layer's anchor, corrected for the current render scale.
         /// </summary>
         /// <param name="layer"></param>
+        /// <param name="positionOverride"></param>
         /// <returns></returns>
-        Point GetLayerAnchorPosition(Layer layer);
+        Point GetLayerAnchorPosition(Layer layer, SKPoint? positionOverride = null);
 
         /// <summary>
         ///     Creates a WPF transform group that contains all the transformations required to render the provided layer.
@@ -36,8 +37,9 @@ namespace Artemis.UI.Services.Interfaces
         /// <param name="includeTranslation"></param>
         /// <param name="includeScale"></param>
         /// <param name="includeRotation"></param>
+        /// <param name="anchorOverride"></param>
         /// <returns></returns>
-        SKPath GetLayerPath(Layer layer, bool includeTranslation, bool includeScale, bool includeRotation);
+        SKPath GetLayerPath(Layer layer, bool includeTranslation, bool includeScale, bool includeRotation, SKPoint? anchorOverride = null);
 
         /// <summary>
         ///     Returns a new point scaled to the layer.
@@ -47,5 +49,7 @@ namespace Artemis.UI.Services.Interfaces
         /// <param name="absolute"></param>
         /// <returns></returns>
         SKPoint GetScaledPoint(Layer layer, SKPoint point, bool absolute);
+
+        SKPoint GetDragOffset(Layer layer, SKPoint dragStart);
     }
 }

src/Artemis.UI/Services/LayerEditorService.cs

@@ -32,10 +32,12 @@ namespace Artemis.UI.Services
         }
 
         /// <inheritdoc />
-        public Point GetLayerAnchorPosition(Layer layer)
+        public Point GetLayerAnchorPosition(Layer layer, SKPoint? positionOverride = null)
         {
             var layerBounds = GetLayerBounds(layer).ToSKRect();
             var positionProperty = layer.PositionProperty.CurrentValue;
+            if (positionOverride != null)
+                positionProperty = positionOverride.Value;
 
             // Start at the center of the shape
             var position = new Point(layerBounds.MidX, layerBounds.MidY);
@@ -72,12 +74,15 @@ namespace Artemis.UI.Services
         }
 
         /// <inheritdoc />
-        public SKPath GetLayerPath(Layer layer, bool includeTranslation, bool includeScale, bool includeRotation)
+        public SKPath GetLayerPath(Layer layer, bool includeTranslation, bool includeScale, bool includeRotation, SKPoint? anchorOverride = null)
         {
             var layerBounds = GetLayerBounds(layer).ToSKRect();
 
             // Apply transformation like done by the core during layer rendering (same differences apply as in GetLayerTransformGroup)
             var anchorPosition = GetLayerAnchorPosition(layer).ToSKPoint();
+            if (anchorOverride != null)
+                anchorPosition = anchorOverride.Value;
+
             var anchorProperty = layer.AnchorPointProperty.CurrentValue;
 
             // Translation originates from the unscaled center of the shape and is tied to the anchor
@@ -113,5 +118,19 @@ namespace Artemis.UI.Services
                 100f / layer.Bounds.Height * (float) (point.Y * renderScale) / 100f
             );
         }
+
+        public SKPoint GetDragOffset(Layer layer, SKPoint dragStart)
+        {
+            // Figure out what the top left will be if the shape moves to the current cursor position
+            var scaledDragStart = GetScaledPoint(layer, dragStart, true);
+            var tempAnchor = GetLayerAnchorPosition(layer, scaledDragStart).ToSKPoint();
+            var tempTopLeft = GetLayerPath(layer, true, true, true, tempAnchor)[0];
+
+            // Get the shape's position
+            var topLeft = GetLayerPath(layer, true, true, true)[0];
+
+            // The difference between the two is the offset
+            return topLeft - tempTopLeft;
+        }
     }
 }