add NetherFossilOptimization

platforms/fabric/src/main/java/com/dfsek/terra/fabric/mixin/fix/NetherFossilOptimization.java

@@ -0,0 +1,42 @@
+package com.dfsek.terra.fabric.mixin.fix;
+
+import com.dfsek.terra.fabric.generation.FabricChunkGeneratorWrapper;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.block.Blocks;
+import net.minecraft.structure.NetherFossilGenerator;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Direction;
+import net.minecraft.util.math.random.ChunkRandom;
+import net.minecraft.world.EmptyBlockView;
+import net.minecraft.world.gen.HeightContext;
+import net.minecraft.world.gen.chunk.VerticalBlockSample;
+import net.minecraft.world.gen.heightprovider.HeightProvider;
+import net.minecraft.world.gen.structure.NetherFossilStructure;
+import net.minecraft.world.gen.structure.Structure;
+import net.minecraft.world.gen.structure.Structure.Context;
+import net.minecraft.world.gen.structure.Structure.StructurePosition;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.util.Optional;
+
+
+/**
+ * Disable fossil generation in Terra worlds, as they are very expensive due to consistently triggering cache misses.
+ *
+ * Currently, on Fabric, Terra cannot be specified as a Nether generator. TODO: logic to turn fossils back on if chunk generator is in nether.
+ */
+@Mixin(NetherFossilStructure.class)
+public class NetherFossilOptimization {
+    @Inject(method = "getStructurePosition", at = @At("HEAD"), cancellable = true)
+    public void injectFossilPositions(Context context, CallbackInfoReturnable<Optional<StructurePosition>> cir) {
+        if(context.chunkGenerator() instanceof FabricChunkGeneratorWrapper) {
+            cir.setReturnValue(Optional.empty());
+        }
+    }
+}

platforms/fabric/src/main/resources/terra.mixins.json

@@ -10,6 +10,7 @@
     "cache.ChunkRegionMixin",
     "cache.ProtoChunkMixin",
     "compat.GenerationSettingsFloraFeaturesMixin",
+    "fix.NetherFossilOptimization",
     "implementations.BiomeMixin",
     "implementations.HandleImplementationMixin",
     "implementations.block.BlockMixin",