Move physics logic into the physics class and properly reset navigation/eye level when gravity changes

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

@@ -31,7 +31,7 @@ public class Creature extends Living<LivingEntity> {
 
     public static void boostrap() {}
 
-    private final Physics physics = new EntityPhysics<>(this, GRAVITY);
+    private final EntityPhysics<Creature> physics = new EntityPhysics<>(this, GRAVITY);
 
     public Creature(LivingEntity entity) {
         super(entity, EFFECT);
@@ -52,6 +52,13 @@ public class Creature extends Living<LivingEntity> {
         builder.add(PlayerAttributes.ENTITY_GRAVTY_MODIFIER);
     }
 
+
+    @Override
+    public void tick() {
+        super.tick();
+        physics.tick();
+    }
+
     @Override
     public Race getSpecies() {
         return Race.HUMAN;

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

@@ -10,21 +10,26 @@ import net.minecraft.block.BlockState;
 import net.minecraft.block.FenceGateBlock;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.damage.DamageSource;
 import net.minecraft.entity.data.TrackedData;
+import net.minecraft.entity.mob.MobEntity;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.particle.BlockStateParticleEffect;
 import net.minecraft.particle.ParticleTypes;
 import net.minecraft.tag.BlockTags;
+import net.minecraft.util.Tickable;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.Vec3d;
 
-public class EntityPhysics<T extends Owned<? extends Entity>> implements Physics, Copieable<EntityPhysics<T>> {
+public class EntityPhysics<T extends Owned<? extends Entity>> implements Physics, Copieable<EntityPhysics<T>>, Tickable {
 
     private final TrackedData<Float> gravity;
 
     protected final T pony;
 
+    private float lastGravity = 1;
+
     public EntityPhysics(T pony, TrackedData<Float> gravity) {
         this(pony, gravity, true);
     }
@@ -38,6 +43,37 @@ public class EntityPhysics<T extends Owned<? extends Entity>> implements Physics
         }
     }
 
+    @Override
+    public void tick() {
+        Entity entity = pony.getMaster();
+
+        if (isGravityNegative()) {
+            if (entity.getY() > entity.world.getHeight() + 64) {
+                entity.damage(DamageSource.OUT_OF_WORLD, 4.0F);
+            }
+
+            entity.setOnGround(!entity.world.isAir(new BlockPos(entity.getX(), Math.floor(entity.getBoundingBox().maxY + 0.25), entity.getZ())));
+        }
+
+        float gravity = this.getGravityModifier();
+        if (gravity != lastGravity) {
+            lastGravity = gravity;
+
+            onGravitychanged();
+        }
+    }
+
+    protected void onGravitychanged() {
+        Entity entity = pony.getMaster();
+
+        entity.calculateDimensions();
+
+        if (!entity.world.isClient && entity instanceof MobEntity) {
+            ((MobEntity)entity).getNavigation().stop();
+            ((MobEntity)entity).setTarget(null);
+        }
+    }
+
     @Override
     public boolean isFlying() {
         return false;
@@ -135,4 +171,5 @@ public class EntityPhysics<T extends Owned<? extends Entity>> implements Physics
     public void fromNBT(CompoundTag compound) {
         setBaseGravityModifier(compound.getFloat("gravity"));
     }
+
 }

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

@@ -8,7 +8,6 @@ import com.minelittlepony.unicopia.item.enchantment.UEnchantments;
 import com.minelittlepony.unicopia.util.VecHelper;
 
 import net.minecraft.enchantment.EnchantmentHelper;
-import net.minecraft.entity.Entity;
 import net.minecraft.entity.ItemEntity;
 import net.minecraft.entity.MovementType;
 import net.minecraft.entity.data.DataTracker;
@@ -21,16 +20,15 @@ import net.minecraft.nbt.CompoundTag;
 import net.minecraft.particle.ParticleEffect;
 import net.minecraft.particle.ParticleTypes;
 import net.minecraft.util.ActionResult;
-import net.minecraft.util.Tickable;
 import net.minecraft.util.math.Vec3d;
 
 public class ItemImpl implements Equine<ItemEntity>, Owned<ItemEntity> {
     private static final TrackedData<Integer> ITEM_RACE = DataTracker.registerData(ItemEntity.class, TrackedDataHandlerRegistry.INTEGER);
-    private static final TrackedData<Float> ITEM_GRAVITY = DataTracker.registerData(ItemEntity.class, TrackedDataHandlerRegistry.FLOAT);
+    static final TrackedData<Float> ITEM_GRAVITY = DataTracker.registerData(ItemEntity.class, TrackedDataHandlerRegistry.FLOAT);
 
     private final ItemEntity owner;
 
-    private final ItemPhysics physics = new ItemPhysics();
+    private final ItemPhysics physics = new ItemPhysics(this);
 
     private Race serverRace;
 
@@ -141,49 +139,6 @@ public class ItemImpl implements Equine<ItemEntity>, Owned<ItemEntity> {
         ActionResult onGroundTick(IItemEntity entity);
     }
 
-    class ItemPhysics extends EntityPhysics<ItemImpl> implements Tickable {
-
-        private float serverGravity;
-
-        public ItemPhysics() {
-            super(ItemImpl.this, ITEM_GRAVITY, false);
-        }
-
-        @Override
-        public void tick() {
-            if (!owner.world.isClient) {
-                float gravity = getBaseGravityModifier();
-                if (gravity != serverGravity) {
-                    serverGravity = gravity;
-                    setBaseGravityModifier(gravity == 0 ? 1 : gravity * 2);
-                    setBaseGravityModifier(gravity);
-                }
-            }
-
-            if (isGravityNegative() && !owner.getStack().isEmpty()) {
-                owner.setNoGravity(true);
-                owner.addVelocity(
-                        0,
-                        0.04
-                        + calcGravity(-0.04D), // apply our own
-                    0
-                );
-
-                if (!owner.isOnGround()
-                        || Entity.squaredHorizontalLength(owner.getVelocity()) > 9.999999747378752E-6D) {
-
-                    float above = 0.98f;
-                    if (owner.verticalCollision) {
-                       above *= owner.world.getBlockState(owner.getBlockPos().up()).getBlock().getSlipperiness();
-                       //above /= 9;
-                    }
-
-                    owner.setVelocity(owner.getVelocity().multiply(above, 1, above));
-                }
-            }
-        }
-    }
-
     public interface ClingyItem {
         ClingyItem DEFAULT = stack -> {
             return EnchantmentHelper.getLevel(UEnchantments.CLINGY, stack) > 0;

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

@@ -0,0 +1,48 @@
+package com.minelittlepony.unicopia.entity;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.ItemEntity;
+
+class ItemPhysics extends EntityPhysics<ItemImpl> {
+    public ItemPhysics(ItemImpl itemImpl) {
+        super(itemImpl, ItemImpl.ITEM_GRAVITY, false);
+    }
+
+    @Override
+    public void tick() {
+        super.tick();
+
+        ItemEntity owner = pony.getMaster();
+
+        if (isGravityNegative() && !owner.getStack().isEmpty()) {
+            owner.setNoGravity(true);
+            owner.addVelocity(
+                    0,
+                    0.04
+                    + calcGravity(-0.04D), // apply our own
+                0
+            );
+
+            if (!owner.isOnGround()
+                    || Entity.squaredHorizontalLength(owner.getVelocity()) > 9.999999747378752E-6D) {
+
+                float above = 0.98f;
+                if (owner.verticalCollision) {
+                   above *= owner.world.getBlockState(owner.getBlockPos().up()).getBlock().getSlipperiness();
+                   //above /= 9;
+                }
+
+                owner.setVelocity(owner.getVelocity().multiply(above, 1, above));
+            }
+        }
+    }
+
+    @Override
+    protected void onGravitychanged() {
+        if (!pony.getMaster().world.isClient) {
+            float gravity = this.getBaseGravityModifier();
+            setBaseGravityModifier(gravity == 0 ? 1 : gravity * 2);
+            setBaseGravityModifier(gravity);
+        }
+    }
+}

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

@@ -19,7 +19,6 @@ import net.minecraft.entity.projectile.ProjectileEntity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.CompoundTag;
 import net.minecraft.util.Hand;
-import net.minecraft.util.math.BlockPos;
 
 public abstract class Living<T extends LivingEntity> implements Equine<T>, Caster<T> {
 
@@ -97,13 +96,6 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
         prevSneaking = entity.isSneaking();
         prevLanded = entity.isOnGround();
 
-        if (getPhysics().isGravityNegative() && entity.getY() > entity.world.getHeight() + 64) {
-            entity.damage(DamageSource.OUT_OF_WORLD, 4.0F);
-        }
-        if (getPhysics().isGravityNegative()) {
-            entity.setOnGround(!entity.world.isAir(new BlockPos(entity.getX(), Math.floor(entity.getBoundingBox().maxY + 0.25), entity.getZ())));
-        }
-
         enchants.tick();
     }
 

src/main/java/com/minelittlepony/unicopia/entity/player/PlayerPhysics.java

@@ -64,6 +64,8 @@ public class PlayerPhysics extends EntityPhysics<Pony> implements Tickable, Moti
 
     @Override
     public void tick() {
+        super.tick();
+
         if (wallHitCooldown > 0) {
             wallHitCooldown--;
         }

src/main/java/com/minelittlepony/unicopia/item/enchantment/AttributedEnchantment.java

@@ -5,7 +5,6 @@ import java.util.Map;
 
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.Multimap;
-import com.minelittlepony.unicopia.AwaitTickQueue;
 import com.minelittlepony.unicopia.entity.Living;
 
 import net.minecraft.enchantment.EnchantmentTarget;
@@ -44,7 +43,6 @@ public class AttributedEnchantment extends SimpleEnchantment {
                 instance.removeModifier(modifier.getId());
                 instance.addPersistentModifier(modifier);
             });
-            entity.calculateDimensions();
         }
     }
 
@@ -57,9 +55,6 @@ public class AttributedEnchantment extends SimpleEnchantment {
             instance.tryRemoveModifier(modifierSupplier.get(user, 1).getId());
         });
         user.getEnchants().remove(this);
-        AwaitTickQueue.scheduleTask(entity.world, w -> {
-            entity.calculateDimensions();
-       }, 1);
     }
 
     public void getModifiers(Living<?> user, int level, Map<EquipmentSlot, Multimap<EntityAttribute, EntityAttributeModifier>> output) {