From 6ad962fc8b7ec6e7390be778012d17988cb81777 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 9 Mar 2018 14:34:05 +0900
Subject: [PATCH] Interpolate ParallaxContainer's scale

Things were a bit jumpy when a screen was adjusting `ParallaxAmount`. This smoothes the applied scale changes to look great again.

Most noticeable when hitting the retry hotkey (`~`) from gameplay.
---
 osu.Game/Graphics/Containers/ParallaxContainer.cs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Graphics/Containers/ParallaxContainer.cs b/osu.Game/Graphics/Containers/ParallaxContainer.cs
index febe52d775..97d6225534 100644
--- a/osu.Game/Graphics/Containers/ParallaxContainer.cs
+++ b/osu.Game/Graphics/Containers/ParallaxContainer.cs
@@ -66,8 +66,10 @@ protected override void Update()
             {
                 Vector2 offset = (input.CurrentState.Mouse == null ? Vector2.Zero : ToLocalSpace(input.CurrentState.Mouse.NativeState.Position) - DrawSize / 2) * ParallaxAmount;
 
-                content.Position = Interpolation.ValueAt(MathHelper.Clamp(Clock.ElapsedFrameTime, 0, 1000), content.Position, offset, 0, 1000, Easing.OutQuint);
-                content.Scale = new Vector2(1 + ParallaxAmount);
+                double elapsed = MathHelper.Clamp(Clock.ElapsedFrameTime, 0, 1000);
+
+                content.Position = Interpolation.ValueAt(elapsed, content.Position, offset, 0, 1000, Easing.OutQuint);
+                content.Scale = Interpolation.ValueAt(elapsed, content.Scale, new Vector2(1 + ParallaxAmount), 0, 1000, Easing.OutQuint);
             }
 
             firstUpdate = false;