new: cache sea level in NoiseChunkGenerator

src/main/java/me/jellysquid/mods/lithium/common/config/LithiumConfig.java

@@ -73,6 +73,7 @@ private LithiumConfig() {
 
         this.addMixinRule("gen", true);
         this.addMixinRule("gen.biome_noise_cache", true);
+        this.addMixinRule("gen.cached_generator_settings", true);
         this.addMixinRule("gen.chunk_region", true);
         this.addMixinRule("gen.fast_island_noise", true);
         this.addMixinRule("gen.fast_layer_sampling", true);

src/main/java/me/jellysquid/mods/lithium/mixin/gen/cached_generator_settings/NoiseChunkGeneratorMixin.java

@@ -0,0 +1,37 @@
+package me.jellysquid.mods.lithium.mixin.gen.cached_generator_settings;
+
+import net.minecraft.world.biome.source.BiomeSource;
+import net.minecraft.world.gen.chunk.ChunkGeneratorSettings;
+import net.minecraft.world.gen.chunk.NoiseChunkGenerator;
+import org.spongepowered.asm.mixin.*;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+import java.util.function.Supplier;
+
+@Mixin(NoiseChunkGenerator.class)
+public class NoiseChunkGeneratorMixin {
+    private int cachedSeaLevel;
+
+    /**
+     * Use cached sea level instead of retrieving from the registry every time.
+     * This method is called for every block in the chunk so this will save a lot of registry lookups.
+     *
+     * @author SuperCoder79
+     */
+    @Overwrite
+    public int getSeaLevel() {
+        return this.cachedSeaLevel;
+    }
+
+    /**
+     * Initialize the cache early in the ctor to avoid potential future problems with uninitialized usages
+     */
+    @Inject(method = "<init>(Lnet/minecraft/world/biome/source/BiomeSource;Lnet/minecraft/world/biome/source/BiomeSource;JLjava/util/function/Supplier;)V",
+            at = @At(value = "INVOKE", shift = At.Shift.BEFORE,
+                    target = "Lnet/minecraft/world/gen/chunk/ChunkGeneratorSettings;getGenerationShapeConfig()Lnet/minecraft/world/gen/chunk/GenerationShapeConfig;"))
+    private void hookConstructor(BiomeSource populationSource, BiomeSource biomeSource, long seed, Supplier<ChunkGeneratorSettings> settings, CallbackInfo ci) {
+        this.cachedSeaLevel = settings.get().getSeaLevel();
+    }
+}

src/main/resources/lithium.mixins.json

@@ -79,6 +79,7 @@
     "gen.biome_noise_cache.InitLayerMixin",
     "gen.biome_noise_cache.MergingLayerMixin",
     "gen.biome_noise_cache.ParentedLayerMixin",
+    "gen.cached_generator_settings.NoiseChunkGeneratorMixin",
     "gen.chunk_region.ChunkRegionMixin",
     "gen.fast_island_noise.NoiseChunkGeneratorMixin",
     "gen.fast_island_noise.TheEndBiomeSourceMixin",