Configure skeletons to target flying players over players on the ground, and fire at them with more accuracy

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

@@ -17,6 +17,8 @@ import com.minelittlepony.unicopia.entity.ai.BreakHeartGoal;
 import com.minelittlepony.unicopia.entity.ai.DynamicTargetGoal;
 import com.minelittlepony.unicopia.entity.ai.EatMuffinGoal;
 import com.minelittlepony.unicopia.entity.ai.FleeExplosionGoal;
+import com.minelittlepony.unicopia.entity.ai.PrioritizedActiveTargetGoal;
+import com.minelittlepony.unicopia.entity.ai.TargettingUtil;
 import com.minelittlepony.unicopia.entity.ai.WantItTakeItGoal;
 import com.minelittlepony.unicopia.entity.mob.UEntityAttributes;
 
@@ -152,6 +154,9 @@ public class Creature extends Living<LivingEntity> implements WeaklyOwned.Mutabl
         }
         if (entity.getType().getSpawnGroup() == SpawnGroup.MONSTER) {
             goals.add(3, new BreakHeartGoal((MobEntity)entity, targetter));
+            if (entity instanceof AbstractSkeletonEntity) {
+                targets.add(1, new PrioritizedActiveTargetGoal<>((MobEntity)entity, PlayerEntity.class, TargettingUtil.FLYING_PREFERRED, true));
+            }
         }
         if (entity instanceof PigEntity pig) {
             eatMuffinGoal = new EatMuffinGoal(pig, targetter);

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

@@ -98,7 +98,6 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
     private final LandingEventHandler landEvent = addTicker(new LandingEventHandler(this));
     private final Enchantments enchants = addTicker(new Enchantments(this));
     private final ItemTracker armour = addTicker(new ItemTracker(this));
-    //private final Transportation<T> transportation = new Transportation<>(this);
     private final Transportation<T> transportation = new Transportation<>(this);
 
     protected Living(T entity, TrackedData<NbtCompound> effect) {

src/main/java/com/minelittlepony/unicopia/entity/ai/PrioritizedActiveTargetGoal.java

@@ -0,0 +1,35 @@
+package com.minelittlepony.unicopia.entity.ai;
+
+import java.util.Comparator;
+import java.util.function.Predicate;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.ai.goal.ActiveTargetGoal;
+import net.minecraft.entity.mob.MobEntity;
+
+public class PrioritizedActiveTargetGoal<T extends LivingEntity> extends ActiveTargetGoal<T> {
+
+    private final Comparator<T> prioritySorting;
+
+    public PrioritizedActiveTargetGoal(MobEntity mob, Class<T> targetClass, Comparator<T> prioritySorting, boolean checkVisibility) {
+        super(mob, targetClass, checkVisibility);
+        this.prioritySorting = prioritySorting;
+    }
+
+    public PrioritizedActiveTargetGoal(MobEntity mob, Class<T> targetClass, Comparator<T> prioritySorting, boolean checkVisibility, Predicate<LivingEntity> targetPredicate) {
+        super(mob, targetClass, 10, checkVisibility, false, targetPredicate);
+        this.prioritySorting = prioritySorting;
+    }
+
+    public PrioritizedActiveTargetGoal(MobEntity mob, Class<T> targetClass, Comparator<T> prioritySorting, boolean checkVisibility, boolean checkCanNavigate) {
+        super(mob, targetClass, 10, checkVisibility, checkCanNavigate, null);
+        this.prioritySorting = prioritySorting;
+    }
+
+    @Override
+    protected void findClosestTarget() {
+        targetEntity = TargettingUtil.getTargets(targetClass, targetPredicate, mob, getSearchBox(getFollowRange()))
+                .sorted(prioritySorting.thenComparing(TargettingUtil.nearestTo(mob)))
+                .findFirst()
+                .orElse(null);
+    }
+}

src/main/java/com/minelittlepony/unicopia/entity/ai/TargettingUtil.java

@@ -0,0 +1,40 @@
+package com.minelittlepony.unicopia.entity.ai;
+
+import java.util.Comparator;
+import java.util.stream.Stream;
+
+import com.minelittlepony.unicopia.entity.player.Pony;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.ai.TargetPredicate;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.math.Box;
+import net.minecraft.util.math.Vec3d;
+
+public interface TargettingUtil {
+    Comparator<PlayerEntity> FLYING_PREFERRED = Comparator.comparing(e -> Pony.of(e).getPhysics().isFlying() ? 0 : 1);
+
+    @SuppressWarnings("unchecked")
+    static <T extends LivingEntity> Stream<T> getTargets(Class<T> type, TargetPredicate predicate, LivingEntity subject, Box searchArea) {
+        if (type == PlayerEntity.class || type == ServerPlayerEntity.class) {
+            return (Stream<T>)subject.getWorld().getPlayers(predicate, subject, searchArea).stream();
+        }
+        return subject.getWorld().getTargets(type, predicate, subject, searchArea).stream();
+    }
+
+    static <T extends Entity> Comparator<T> nearestTo(LivingEntity subject) {
+        Vec3d fromPos = subject.getEyePos();
+        return Comparator.comparing(e -> fromPos.distanceTo(e.getPos()));
+    }
+
+    static Vec3d getProjectedPos(LivingEntity entity) {
+        if (entity instanceof PlayerEntity player) {
+            Vec3d velocity = Pony.of(player).getPhysics().getClientVelocity();
+            System.out.println(velocity);
+            return entity.getEyePos().add(velocity.multiply(1.5)).add(0, -1, 0);
+        }
+        return entity.getEyePos().add(entity.getVelocity());
+    }
+}

src/main/java/com/minelittlepony/unicopia/mixin/MixinAbstractSkeletonEntity.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.ModifyArg;
+
+import com.minelittlepony.unicopia.entity.ai.TargettingUtil;
+import com.minelittlepony.unicopia.entity.player.Pony;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.mob.AbstractSkeletonEntity;
+import net.minecraft.entity.mob.HostileEntity;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.entity.projectile.PersistentProjectileEntity;
+import net.minecraft.util.math.Vec3d;
+
+@Mixin(AbstractSkeletonEntity.class)
+abstract class MixinAbstractSkeletonEntity extends HostileEntity {
+    MixinAbstractSkeletonEntity() { super(null, null); }
+
+    @ModifyArg(method = "attack", at = @At(value = "INVOKE", target = "net/minecraft/world/World.spawnEntity(Lnet/minecraft/entity/Entity;)Z"))
+    private Entity modifyAccuracy(Entity entity) {
+        if (entity instanceof PersistentProjectileEntity projectile && getTarget() instanceof PlayerEntity player && Pony.of(player).getPhysics().isFlying()) {
+            Vec3d targetPos = TargettingUtil.getProjectedPos(player)
+                    .add(0, player.getHeight() * 0.33333F, 0)
+                    .subtract(projectile.getPos());
+            projectile.setVelocity(targetPos.x, targetPos.y + targetPos.horizontalLength() * 0.2, targetPos.z, 1.6F, (14 - getWorld().getDifficulty().getId() * 4) * 0.25F);
+        }
+        return entity;
+    }
+}

src/main/resources/unicopia.mixin.json

@@ -7,6 +7,7 @@
   "compatibilityLevel": "JAVA_17",
   "mixins": [
     "MixinAbstractDecorationEntity",
+    "MixinAbstractSkeletonEntity",
     "MixinBlazeEntity",
     "MixinBlock",
     "MixinBlockEntity",