fix: broken cache merging

Author: ishland

c2me-opts-dfc/src/main/java/com/ishland/c2me/opts/dfc/common/ducks/IEqualityOverriding.java

@@ -4,4 +4,6 @@ public interface IEqualityOverriding {
 
     void c2me$overrideEquality(Object object);
 
+    Object c2me$getOverriddenEquality();
+
 }

c2me-opts-dfc/src/main/java/com/ishland/c2me/opts/dfc/common/gen/SubCompiledDensityFunction.java

@@ -89,7 +89,7 @@ public void fill(double[] densities, EachApplier applier) {
     @Override
     public DensityFunction apply(DensityFunctionVisitor visitor) {
         if (this.getClass() != SubCompiledDensityFunction.class) {
-            throw new UnsupportedOperationException();
+            throw new AbstractMethodError();
         }
         boolean modified = false;
         Supplier<DensityFunction> fallback = this.blendingFallback != null ? Suppliers.memoize(() -> {

c2me-opts-dfc/src/main/java/com/ishland/c2me/opts/dfc/mixin/MixinChunkNoiseSampler.java

@@ -4,9 +4,14 @@
 import com.ishland.c2me.opts.dfc.common.ducks.ICoordinatesFilling;
 import com.ishland.c2me.opts.dfc.common.util.ArrayCache;
 import net.minecraft.world.gen.chunk.ChunkNoiseSampler;
+import net.minecraft.world.gen.densityfunction.DensityFunction;
+import net.minecraft.world.gen.densityfunction.DensityFunctionTypes;
 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;
 
 @Mixin(ChunkNoiseSampler.class)
 public class MixinChunkNoiseSampler implements IArrayCacheCapable, ICoordinatesFilling {
@@ -16,6 +21,7 @@ public class MixinChunkNoiseSampler implements IArrayCacheCapable, ICoordinatesF
     @Shadow private int startBlockY;
     @Shadow private int startBlockX;
     @Shadow private int startBlockZ;
+    @Shadow private boolean isInInterpolationLoop;
     private final ArrayCache c2me$arrayCache = new ArrayCache();
 
     @Override
@@ -42,4 +48,11 @@ public class MixinChunkNoiseSampler implements IArrayCacheCapable, ICoordinatesF
             }
         }
     }
+
+    @Inject(method = "getActualDensityFunctionImpl", at = @At("HEAD"))
+    private void protectInterpolationLoop(DensityFunction function, CallbackInfoReturnable<DensityFunction> cir) {
+        if (this.isInInterpolationLoop && function instanceof DensityFunctionTypes.Wrapping) {
+            throw new IllegalStateException("Cannot create more wrapping during interpolation loop");
+        }
+    }
 }

c2me-opts-dfc/src/main/java/com/ishland/c2me/opts/dfc/mixin/MixinDFTWrapping.java

@@ -14,7 +14,7 @@
 import org.spongepowered.asm.mixin.Unique;
 
 @Mixin(DensityFunctionTypes.Wrapping.class)
-public abstract class MixinDFTWrapping implements IFastCacheLike, IEqualityOverriding {
+public abstract class MixinDFTWrapping implements IFastCacheLike, IEqualityOverriding, DensityFunctionTypes.Wrapper {
 
     @Mutable
     @Shadow @Final private DensityFunction wrapped;
@@ -58,7 +58,20 @@ public abstract class MixinDFTWrapping implements IFastCacheLike, IEqualityOverr
 
     @Override
     public void c2me$overrideEquality(Object object) {
-        this.c2me$optionalEquality = object;
+        Object inner = object;
+        while (true) {
+            Object inner1 = inner instanceof IEqualityOverriding e1 ? e1.c2me$getOverriddenEquality() : null;
+            if (inner1 == null) {
+                this.c2me$optionalEquality = inner;
+                break;
+            }
+            inner = inner1;
+        }
+    }
+
+    @Override
+    public Object c2me$getOverriddenEquality() {
+        return this.c2me$optionalEquality;
     }
 
     @WrapMethod(method = "hashCode")
@@ -72,12 +85,18 @@ private int wrapHashCode(Operation<Integer> original) {
     }
 
     @WrapMethod(method = "equals")
-    private boolean wrapEquals(Object object, Operation<Boolean> original) {
-        Object c2me$optionalEquality1 = this.c2me$optionalEquality;
-        if (c2me$optionalEquality1 != null) {
-            return c2me$optionalEquality1.equals(object);
+    private boolean wrapEquals(Object that, Operation<Boolean> original) {
+        Object a = this.c2me$getOverriddenEquality();
+        Object b = that instanceof IEqualityOverriding equalityOverriding ? equalityOverriding.c2me$getOverriddenEquality() : null;
+        if (a == null) {
+            return original.call(b != null ? b : that);
         } else {
-            return original.call(object);
+            return a.equals(b != null ? b : that);
         }
     }
+
+    @Override
+    public DensityFunction apply(DensityFunctionVisitor visitor) {
+        return visitor.apply(this.c2me$withDelegate(this.wrapped().apply(visitor)));
+    }
 }