From d55f42dc2eed23c66208bd906386c09ff0a8dcb4 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 12 May 2021 15:05:53 +0900
Subject: [PATCH 1/2] Show anchor and origin in skin blueprints when selected

---
 osu.Game/Skinning/Editor/SkinBlueprint.cs | 64 ++++++++++++++++++++++-
 1 file changed, 62 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Skinning/Editor/SkinBlueprint.cs b/osu.Game/Skinning/Editor/SkinBlueprint.cs
index 23411f2b3d..7db5bc7ead 100644
--- a/osu.Game/Skinning/Editor/SkinBlueprint.cs
+++ b/osu.Game/Skinning/Editor/SkinBlueprint.cs
@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
@@ -21,6 +22,8 @@ namespace osu.Game.Skinning.Editor
 
         private Container outlineBox;
 
+        private AnchorOriginVisualiser anchorOriginVisualiser;
+
         private Drawable drawable => (Drawable)Item;
 
         /// <summary>
@@ -69,9 +72,13 @@ namespace osu.Game.Skinning.Editor
                             Font = OsuFont.Default.With(size: 10, weight: FontWeight.Bold),
                             Anchor = Anchor.BottomRight,
                             Origin = Anchor.TopRight,
-                        }
+                        },
                     },
                 },
+                anchorOriginVisualiser = new AnchorOriginVisualiser(drawable)
+                {
+                    Alpha = 0,
+                }
             };
         }
 
@@ -80,7 +87,7 @@ namespace osu.Game.Skinning.Editor
             base.LoadComplete();
 
             updateSelectedState();
-            box.FadeInFromZero(200, Easing.OutQuint);
+            this.FadeInFromZero(200, Easing.OutQuint);
         }
 
         protected override void OnSelected()
@@ -99,6 +106,8 @@ namespace osu.Game.Skinning.Editor
         {
             outlineBox.FadeColour(colours.Pink.Opacity(IsSelected ? 1 : 0.5f), 200, Easing.OutQuint);
             outlineBox.Child.FadeTo(IsSelected ? 0.2f : 0, 200, Easing.OutQuint);
+
+            anchorOriginVisualiser.FadeTo(IsSelected ? 1 : 0, 200, Easing.OutQuint);
         }
 
         private Quad drawableQuad;
@@ -123,4 +132,55 @@ namespace osu.Game.Skinning.Editor
 
         public override Quad SelectionQuad => drawable.ScreenSpaceDrawQuad;
     }
+
+    internal class AnchorOriginVisualiser : CompositeDrawable
+    {
+        private readonly Drawable drawable;
+
+        private readonly Box originBox;
+
+        private readonly Box anchorBox;
+        private readonly Box anchorLine;
+
+        public AnchorOriginVisualiser(Drawable drawable)
+        {
+            this.drawable = drawable;
+
+            InternalChildren = new Drawable[]
+            {
+                anchorLine = new Box
+                {
+                    Colour = Color4.Yellow,
+                    Height = 2,
+                },
+                originBox = new Box
+                {
+                    Colour = Color4.Red,
+                    Origin = Anchor.Centre,
+                    Size = new Vector2(5),
+                },
+                anchorBox = new Box
+                {
+                    Colour = Color4.Red,
+                    Origin = Anchor.Centre,
+                    Size = new Vector2(5),
+                },
+            };
+        }
+
+        protected override void Update()
+        {
+            base.Update();
+
+            originBox.Position = drawable.ToSpaceOfOtherDrawable(drawable.OriginPosition, this);
+            anchorBox.Position = drawable.Parent.ToSpaceOfOtherDrawable(drawable.AnchorPosition, this);
+
+            var point1 = ToLocalSpace(anchorBox.ScreenSpaceDrawQuad.Centre);
+            var point2 = ToLocalSpace(originBox.ScreenSpaceDrawQuad.Centre);
+
+            anchorLine.Position = point1;
+            anchorLine.Width = (point2 - point1).Length;
+            anchorLine.Rotation = MathHelper.RadiansToDegrees(MathF.Atan2(point2.Y - point1.Y, point2.X - point1.X));
+        }
+    }
 }

From df77b28b48b8a58a92380c458251efcaf73773c2 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 13 May 2021 18:39:21 +0900
Subject: [PATCH 2/2] Add a flimsy guard against null parent to avoid crashes
 on exit sequence

---
 osu.Game/Skinning/Editor/SkinBlueprint.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/osu.Game/Skinning/Editor/SkinBlueprint.cs b/osu.Game/Skinning/Editor/SkinBlueprint.cs
index 7db5bc7ead..b337aa53c4 100644
--- a/osu.Game/Skinning/Editor/SkinBlueprint.cs
+++ b/osu.Game/Skinning/Editor/SkinBlueprint.cs
@@ -172,6 +172,9 @@ namespace osu.Game.Skinning.Editor
         {
             base.Update();
 
+            if (drawable.Parent == null)
+                return;
+
             originBox.Position = drawable.ToSpaceOfOtherDrawable(drawable.OriginPosition, this);
             anchorBox.Position = drawable.Parent.ToSpaceOfOtherDrawable(drawable.AnchorPosition, this);