More AI fixes for inverted entities

src/main/java/com/minelittlepony/unicopia/entity/RotatedView.java

@@ -1,17 +1,23 @@
 package com.minelittlepony.unicopia.entity;
 
+import java.util.Stack;
+
 import net.minecraft.util.math.BlockPos;
 
 public interface RotatedView {
 
-    void setRotationCenter(int y, int increments);
+    Stack<Integer> getRotations();
 
-    int getRotationY();
+    boolean hasTransform();
 
-    int getRotationIncrements();
+    default void pushRotation(int y) {
+        getRotations().add(y);
+    }
 
-    default void clearRotation() {
-        setRotationCenter(0, 0);
+    default void popRotation() {
+        if (!getRotations().isEmpty()) {
+            getRotations().pop();
+        }
     }
 
     default BlockPos applyRotation(BlockPos pos) {
@@ -19,14 +25,14 @@ public interface RotatedView {
         if (newY == pos.getY()) {
             return pos;
         }
-        return new BlockPos(pos.getX(), applyRotation(pos.getY()), pos.getZ());
+        return new BlockPos(pos.getX(), newY, pos.getZ());
     }
 
     default int applyRotation(int y) {
-        if (getRotationIncrements() == 0) {
+        if (!hasTransform() || getRotations().isEmpty()) {
             return y;
         }
-        return y - ((y - getRotationY()) * 2);
+        return y - ((y - getRotations().peek()) * 2);
     }
 
 }

src/main/java/com/minelittlepony/unicopia/mixin/MixinBrain.java

@@ -0,0 +1,31 @@
+package com.minelittlepony.unicopia.mixin;
+
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import com.minelittlepony.unicopia.entity.RotatedView;
+import com.minelittlepony.unicopia.entity.Equine;
+import com.minelittlepony.unicopia.entity.Living;
+
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.ai.brain.Brain;
+import net.minecraft.server.world.ServerWorld;
+
+@Mixin(Brain.class)
+abstract class MixinBrain<E extends LivingEntity> {
+
+    @Inject(method = "tick", at = @At("HEAD"))
+    public void beforeTickAi(ServerWorld world, E entity, CallbackInfo into) {
+        Equine<?> eq = Equine.of(entity);
+
+        if (eq instanceof Living<?> && eq.getPhysics().isGravityNegative()) {
+            ((RotatedView)world).pushRotation((int)entity.getY());
+        }
+    }
+
+    @Inject(method = "tick", at = @At("RETURN"))
+    public void afterTickAi(ServerWorld world, E entity, CallbackInfo into) {
+        ((RotatedView)world).popRotation();
+    }
+}

src/main/java/com/minelittlepony/unicopia/mixin/MixinMobEntity.java

@@ -37,12 +37,12 @@ abstract class MixinMobEntity extends LivingEntity implements PonyContainer<Equi
         Equine<?> eq = Equine.of(this);
 
         if (eq instanceof Living<?> && eq.getPhysics().isGravityNegative()) {
-            ((RotatedView)world).setRotationCenter((int)getY(), 1);
+            ((RotatedView)world).pushRotation((int)getY());
         }
     }
 
     @Inject(method = "tickNewAi", at = @At("RETURN"))
     public void afterTickAi(CallbackInfo into) {
-        ((RotatedView)world).clearRotation();
+        ((RotatedView)world).popRotation();
     }
 }

src/main/java/com/minelittlepony/unicopia/mixin/MixinWorld.java

@@ -1,18 +1,25 @@
 package com.minelittlepony.unicopia.mixin;
 
 import java.util.List;
+import java.util.Stack;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
 
 import javax.annotation.Nullable;
 
 import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.ModifyVariable;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
 
 import com.minelittlepony.unicopia.BlockDestructionManager;
 import com.minelittlepony.unicopia.entity.RotatedView;
 import com.minelittlepony.unicopia.entity.behaviour.Disguise;
 
+import net.minecraft.block.BlockState;
 import net.minecraft.entity.Entity;
+import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Box;
 import net.minecraft.util.shape.VoxelShape;
 import net.minecraft.world.World;
@@ -23,26 +30,19 @@ abstract class MixinWorld implements WorldAccess, BlockDestructionManager.Source
 
     private final BlockDestructionManager destructions = new BlockDestructionManager((World)(Object)this);
 
-    private int rotationY;
-    private int rotationIncrements;
+    private int recurseCount = 0;
+    private Stack<Integer> rotations = new Stack<>();
 
     @Override
-    public void setRotationCenter(int y, int increments) {
-        rotationY = y;
-        rotationIncrements = increments;
+    public Stack<Integer> getRotations() {
+        return rotations;
     }
 
     @Override
-    public int getRotationY() {
-        return rotationY;
+    public boolean hasTransform() {
+        return recurseCount <= 0;
     }
 
-    @Override
-    public int getRotationIncrements() {
-        return rotationIncrements;
-    }
-
-
     @Override
     public BlockDestructionManager getDestructionManager() {
         return destructions;
@@ -59,4 +59,16 @@ abstract class MixinWorld implements WorldAccess, BlockDestructionManager.Source
 
         return WorldAccess.super.getEntityCollisions(entity, box, predicate);
     }
+
+    @ModifyVariable(method = "setBlockState(Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/BlockState;II)Z", at = @At("HEAD"))
+    private BlockPos modifyBlockPos(BlockPos pos) {
+        pos = applyRotation(pos);
+        recurseCount = Math.max(0, recurseCount) + 1;
+        return pos;
+    }
+
+    @Inject(method = "setBlockState(Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/BlockState;II)Z", at = @At("RETURN"))
+    public void onSetBlockState(BlockPos pos, BlockState state, int flags, int maxUpdateDepth, CallbackInfoReturnable<Boolean> info) {
+        recurseCount = Math.max(0, recurseCount - 1);
+    }
 }

src/main/java/com/minelittlepony/unicopia/mixin/MixinWorldChunk.java

@@ -14,7 +14,7 @@ abstract class MixinWorldChunk {
 
     @ModifyVariable(method = {
             "getBlockState(Lnet/minecraft/util/math/BlockPos;)Lnet/minecraft/block/BlockState;",
-            "setBlockState(Lnet/minecraft/util/math/BlockPos;)V",
+            "setBlockState(Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/BlockState;Z)Lnet/minecraft/block/BlockState;",
             "getBlockEntity(Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/world/chunk/WorldChunk$CreationType;)Lnet/minecraft/block/entity/BlockEntity;",
             "setBlockEntity(Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/entity/BlockEntity;)V",
             "removeBlockEntity(Lnet/minecraft/util/math/BlockPos;)V",

src/main/resources/unicopia.mixin.json

@@ -7,6 +7,7 @@
   "mixins": [
     "MixinBlockEntity",
     "MixinBlockItem",
+    "MixinBrain",
     "MixinFallingBlock",
     "MixinItem",
     "MixinItemEntity",