From a3234a52694f55faa130ecbf384f8009b9673509 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 22 Nov 2016 21:22:12 +0900
Subject: [PATCH] Avoid synchronous queries in BackgroundModeBeatmap.

---
 .../Backgrounds/BackgroundModeBeatmap.cs      | 59 ++++++++++++-------
 1 file changed, 39 insertions(+), 20 deletions(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundModeBeatmap.cs b/osu.Game/Screens/Backgrounds/BackgroundModeBeatmap.cs
index 649952ccfb..e599198009 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundModeBeatmap.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundModeBeatmap.cs
@@ -1,9 +1,8 @@
 //Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
 //Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using osu.Framework.Allocation;
 using OpenTK;
-using osu.Framework.Graphics;
-using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Transformations;
 using osu.Game.Beatmaps;
 using osu.Game.Graphics.Background;
@@ -15,6 +14,7 @@ namespace osu.Game.Screens.Backgrounds
         private Background background;
 
         private WorkingBeatmap beatmap;
+        private Vector2 blurTarget;
 
         public WorkingBeatmap Beatmap
         {
@@ -30,20 +30,26 @@ namespace osu.Game.Screens.Backgrounds
 
                 beatmap = value;
 
-                Background oldBackground = background;
-
-                addBackground(background = new Background());
-                background.Sprite.Texture = beatmap.Background;
-
-                if (oldBackground != null)
+                Schedule(() =>
                 {
-                    oldBackground.Depth = 1;
-                    oldBackground.Flush();
-                    oldBackground.FadeOut(250);
-                    oldBackground.Expire();
+                    Background newBackground = new BeatmapBackground(beatmap);
 
-                    background.BlurSigma = oldBackground.BlurSigma;
-                }
+                    newBackground.Preload(Game, delegate
+                    {
+                        Background oldBackground = background;
+
+                        Add(background = newBackground);
+                        background.BlurSigma = blurTarget;
+
+                        if (oldBackground != null)
+                        {
+                            oldBackground.Depth = 1;
+                            oldBackground.Flush();
+                            oldBackground.FadeOut(250);
+                            oldBackground.Expire();
+                        }
+                    });
+                });
             }
         }
 
@@ -52,20 +58,33 @@ namespace osu.Game.Screens.Backgrounds
             Beatmap = beatmap;
         }
 
-        private void addBackground(Background background)
-        {
-            background.CacheDrawnFrameBuffer = true;
-            Add(background);
-        }
-
         public void BlurTo(Vector2 sigma, double duration)
         {
             background?.BlurTo(sigma, duration, EasingTypes.OutExpo);
+            blurTarget = sigma;
         }
 
         public override bool Equals(BackgroundMode other)
         {
             return base.Equals(other) && beatmap == ((BackgroundModeBeatmap)other).Beatmap;
         }
+
+        class BeatmapBackground : Background
+        {
+            private WorkingBeatmap beatmap;
+
+            public BeatmapBackground(WorkingBeatmap beatmap)
+            {
+                this.beatmap = beatmap;
+                CacheDrawnFrameBuffer = true;
+            }
+
+            [BackgroundDependencyLoader]
+            private void load()
+            {
+                Sprite.Texture = beatmap.Background;
+            }
+
+        }
     }
 }