fix MC-298558 (#441)

* fix MC-298558

* use mixin extras expressions for MC-298558 fix

---------

Co-authored-by: MicrocontrollersDev <microcontrollersyt@gmail.com>

Author: isXander

PATCHED.md

@@ -31,6 +31,7 @@
 | Basic    | [MC-217716](https://bugs.mojang.com/browse/MC-217716) | The green nausea overlay isn't removed when switching into spectator mode                                                           |
 | Basic    | [MC-231097](https://bugs.mojang.com/browse/MC-231097) | Holding the "Use" button continues to slow down the player even after the used item has been dropped                                |
 | Basic    | [MC-237493](https://bugs.mojang.com/browse/MC-237493) | Telemetry cannot be disabled                                                                                                        |
+| Basic    | [MC-298558](https://bugs.mojang.com/browse/MC-298558) | Rain fog calculation can overshoot while game is unresponsive                                                                       |
 | Basic    | [MC-268420](https://bugs.mojang.com/browse/MC-268420) | Cooldown indicator flashes when switching items with high attack speed attribute                                                    |
 | Basic    | [MC-259512](https://bugs.mojang.com/browse/MC-259512) | Horizontal camera rotation lags when riding                                                                                         |
 

build.gradle.kts

@@ -49,6 +49,7 @@ loom {
     createRemapConfigurations(gametest.get())
 
     accessWidenerPath.set(file("src/main/resources/debugify.accesswidener"))
+    mixin.useLegacyMixinAp = false
 }
 
 repositories {
@@ -77,6 +78,12 @@ dependencies {
     modImplementation(fabricApi.module("fabric-resource-loader-v0", fabricApiVersion))
     modImplementation("net.fabricmc.fabric-api:fabric-api:$fabricApiVersion")
 
+    "io.github.llamalad7:mixinextras-fabric:$mixinExtrasVersion".let {
+        include(it)
+        implementation(it)
+        /*annotationProcessor(it)*/// only needed if `useLegacyMixinAp = true`
+    }
+
     "modClientImplementation"("dev.isxander:yet-another-config-lib:$yaclVersion") { exclude(module = "fabric-loader") }
     "modClientImplementation"("com.terraformersmc:modmenu:$modMenuVersion") { exclude(module = "fabric-loader") }
 

gradle.properties

@@ -4,6 +4,7 @@ org.gradle.parallel.threads=4
 
 minecraftVersion=1.21.7
 fabricLoaderVersion=0.16.14
+mixinExtrasVersion=0.5.0-rc.4
 
 modrinthId=QwxR6Gcd
 curseforgeId=596224

src/client/java/dev/isxander/debugify/client/mixins/basic/mc298558/AtmosphericFogEnvironmentMixin.java

@@ -0,0 +1,31 @@
+package dev.isxander.debugify.client.mixins.basic.mc298558;
+
+import com.llamalad7.mixinextras.expression.Definition;
+import com.llamalad7.mixinextras.expression.Expression;
+import com.llamalad7.mixinextras.injector.ModifyExpressionValue;
+import com.llamalad7.mixinextras.sugar.Local;
+import dev.isxander.debugify.fixes.BugFix;
+import dev.isxander.debugify.fixes.FixCategory;
+import net.minecraft.client.renderer.fog.environment.AtmosphericFogEnvironment;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+
+@BugFix(id = "MC-298558", category = FixCategory.BASIC, env = BugFix.Env.CLIENT, description = "Rain fog calculation can overshoot while game is unresponsive")
+@Mixin(AtmosphericFogEnvironment.class)
+public class AtmosphericFogEnvironmentMixin {
+
+    /**
+     * The issue stems from the gtDeltaTicks * 0.2, which needs a maximum value of 1.
+     */
+    @Definition(id = "rainFogMultiplier", field = "Lnet/minecraft/client/renderer/fog/environment/AtmosphericFogEnvironment;rainFogMultiplier:F")
+    @Definition(id = "rainLevel", local = @Local(type = float.class, ordinal = 3))
+    @Definition(id = "gtDeltaTicks", local = @Local(type = float.class, ordinal = 1))
+    // `?.` instead of `this.` since the `this` is DUPed making it impossible to target
+    @Expression("?.rainFogMultiplier = ?.rainFogMultiplier + (rainLevel - ?.rainFogMultiplier) * @(gtDeltaTicks) * 0.2")
+    @ModifyExpressionValue(method = "setupFog", at = @At("MIXINEXTRAS:EXPRESSION"))
+    private float clampFog(float original) {
+        // it's impossible to target `gtDeltaTicks * 0.2` since in bytecode
+        // it's `...) * gtDeltaTicks) * 0.2`. so instead just modify `gtDeltaTicks` with min 5, since 5 * 0.2 is 1
+        return Math.min(5f, original);
+    }
+}

src/client/resources/debugify.client.mixins.json

@@ -31,6 +31,7 @@
     "basic.mc237493.TelemetryEventWidgetMixin",
     "basic.mc237493.TelemetryInfoScreenMixin",
     "basic.mc263865.KeyboardHandlerMixin",
+    "basic.mc298558.AtmosphericFogEnvironmentMixin",
     "basic.mc268420.GuiMixin",
     "basic.mc4490.FishingHookRendererMixin",
     "basic.mc46503.ClientPacketListenerMixin",