From 0d77ec013a936fd77b852837b7007229028f34bd Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 28 Mar 2023 14:53:08 +0900
Subject: [PATCH] Fix ruleset-local shader manager not correctly falling back
 to existing cached shaders

---
 .../UI/DrawableRulesetDependencies.cs         | 30 ++++++++++---------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/osu.Game/Rulesets/UI/DrawableRulesetDependencies.cs b/osu.Game/Rulesets/UI/DrawableRulesetDependencies.cs
index 5c031c5f08..e6ee770e19 100644
--- a/osu.Game/Rulesets/UI/DrawableRulesetDependencies.cs
+++ b/osu.Game/Rulesets/UI/DrawableRulesetDependencies.cs
@@ -68,8 +68,7 @@ namespace osu.Game.Rulesets.UI
             SampleStore.PlaybackConcurrency = OsuGameBase.SAMPLE_CONCURRENCY;
             CacheAs(SampleStore = new FallbackSampleStore(SampleStore, parent.Get<ISampleStore>()));
 
-            ShaderManager = new ShaderManager(host.Renderer, new NamespacedResourceStore<byte[]>(resources, @"Shaders"));
-            CacheAs(ShaderManager = new FallbackShaderManager(host.Renderer, ShaderManager, parent.Get<ShaderManager>()));
+            CacheAs(ShaderManager = new RulesetShaderManager(host.Renderer, new NamespacedResourceStore<byte[]>(resources, @"Shaders"), parent.Get<ShaderManager>()));
 
             RulesetConfigManager = parent.Get<IRulesetConfigCache>().GetConfigFor(ruleset);
             if (RulesetConfigManager != null)
@@ -197,24 +196,27 @@ namespace osu.Game.Rulesets.UI
             }
         }
 
-        private class FallbackShaderManager : ShaderManager
+        private class RulesetShaderManager : ShaderManager
         {
-            private readonly ShaderManager primary;
-            private readonly ShaderManager fallback;
+            private readonly ShaderManager parent;
 
-            public FallbackShaderManager(IRenderer renderer, ShaderManager primary, ShaderManager fallback)
-                : base(renderer, new ResourceStore<byte[]>())
+            public RulesetShaderManager(IRenderer renderer, NamespacedResourceStore<byte[]> rulesetResources, ShaderManager parent)
+                : base(renderer, rulesetResources)
             {
-                this.primary = primary;
-                this.fallback = fallback;
+                this.parent = parent;
             }
 
-            public override byte[]? LoadRaw(string name) => primary.LoadRaw(name) ?? fallback.LoadRaw(name);
-
-            protected override void Dispose(bool disposing)
+            public override IShader Load(string vertex, string fragment)
             {
-                base.Dispose(disposing);
-                if (primary.IsNotNull()) primary.Dispose();
+                try
+                {
+                    return base.Load(vertex, fragment);
+                }
+                catch
+                {
+                    // Shader lookup is very non-standard. Rather than returning null on missing shaders, exceptions are thrown.
+                    return parent.Load(vertex, fragment);
+                }
             }
         }
     }