Refactor projectile event handlers

src/main/java/com/minelittlepony/unicopia/ability/magic/SpellPredicate.java

@@ -11,7 +11,6 @@ import net.minecraft.entity.Entity;
 public interface SpellPredicate<T extends Spell> extends Predicate<Spell> {
     SpellPredicate<IllusionarySpell> CAN_SUPPRESS = s -> s instanceof IllusionarySpell;
     SpellPredicate<PlaceableSpell> IS_PLACED = s -> s instanceof PlaceableSpell;
-    SpellPredicate<ProjectileSpell> HAS_PROJECTILE_EVENTS = s -> s instanceof ProjectileSpell;
     SpellPredicate<AbstractDisguiseSpell> IS_DISGUISE = s -> s instanceof AbstractDisguiseSpell;
     SpellPredicate<MimicSpell> IS_MIMIC = s -> s instanceof MimicSpell;
     SpellPredicate<ShieldSpell> IS_SHIELD_LIKE = spell -> spell instanceof ShieldSpell;

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/AbstractDelegatingSpell.java

@@ -13,14 +13,12 @@ import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
 import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 
-import net.minecraft.block.BlockState;
-import net.minecraft.entity.Entity;
 import net.minecraft.nbt.NbtCompound;
-import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
 
-public abstract class AbstractDelegatingSpell implements ProjectileSpell {
+public abstract class AbstractDelegatingSpell implements Spell,
-    private static final Function<Object, ProjectileSpell> PROJECTILE_SPELL = a -> a instanceof ProjectileSpell p ? p : null;
+    ProjectileDelegate.ConfigurationListener, ProjectileDelegate.BlockHitListener, ProjectileDelegate.EntityHitListener {
-    private static final Function<Object, ProjectileDelegate> PROJECTILE_DELEGATE = a -> a instanceof ProjectileDelegate p ? p : null;
 
     private boolean isDirty;
 
@@ -36,12 +34,12 @@ public abstract class AbstractDelegatingSpell implements ProjectileSpell {
 
     @Override
     public boolean equalsOrContains(UUID id) {
-        return ProjectileSpell.super.equalsOrContains(id) || getDelegates().stream().anyMatch(s -> s.equalsOrContains(id));
+        return Spell.super.equalsOrContains(id) || getDelegates().stream().anyMatch(s -> s.equalsOrContains(id));
     }
 
     @Override
     public Stream<Spell> findMatches(Predicate<Spell> predicate) {
-        return Stream.concat(ProjectileSpell.super.findMatches(predicate), getDelegates().stream().flatMap(s -> s.findMatches(predicate)));
+        return Stream.concat(Spell.super.findMatches(predicate), getDelegates().stream().flatMap(s -> s.findMatches(predicate)));
     }
 
     @Override
@@ -95,18 +93,18 @@ public abstract class AbstractDelegatingSpell implements ProjectileSpell {
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
+    public void onImpact(MagicProjectileEntity projectile, BlockHitResult hit) {
-        getDelegates(PROJECTILE_DELEGATE).forEach(a -> a.onImpact(projectile, pos, state));
+        getDelegates(BlockHitListener.PREDICATE).forEach(a -> a.onImpact(projectile, hit));
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
-        getDelegates(PROJECTILE_DELEGATE).forEach(a -> a.onImpact(projectile, entity));
+        getDelegates(EntityHitListener.PREDICATE).forEach(a -> a.onImpact(projectile, hit));
     }
 
     @Override
     public void configureProjectile(MagicProjectileEntity projectile, Caster<?> caster) {
-        getDelegates(PROJECTILE_SPELL).forEach(a -> a.configureProjectile(projectile, caster));
+        getDelegates(ConfigurationListener.PREDICATE).forEach(a -> a.configureProjectile(projectile, caster));
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/ProjectileSpell.java

@@ -1,22 +0,0 @@
-package com.minelittlepony.unicopia.ability.magic.spell;
-
-import com.minelittlepony.unicopia.ability.magic.Caster;
-import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
-import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
-
-import net.minecraft.block.BlockState;
-import net.minecraft.util.math.BlockPos;
-
-/**
- * Magic effects that can be thrown.
- */
-public interface ProjectileSpell extends Spell, ProjectileDelegate {
-    @Override
-    default void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
-        if (!projectile.isClient()) {
-            tick(projectile, Situation.PROJECTILE);
-        }
-    }
-
-    default void configureProjectile(MagicProjectileEntity projectile, Caster<?> caster) { }
-}

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/RainboomAbilitySpell.java

@@ -5,7 +5,6 @@ import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.*;
 import com.minelittlepony.unicopia.block.data.ModificationType;
 import com.minelittlepony.unicopia.entity.player.Pony;
-import com.minelittlepony.unicopia.particle.OrientedBillboardParticleEffect;
 import com.minelittlepony.unicopia.particle.ParticleHandle;
 import com.minelittlepony.unicopia.particle.UParticles;
 import com.minelittlepony.unicopia.util.MagicalDamageSource;

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/AttractiveSpell.java

@@ -9,16 +9,18 @@ import com.minelittlepony.unicopia.particle.FollowingParticleEffect;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
 import com.minelittlepony.unicopia.particle.UParticles;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.MagicalDamageSource;
 import com.minelittlepony.unicopia.util.shape.Sphere;
 
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.ItemEntity;
 import net.minecraft.nbt.NbtCompound;
+import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.Vec3d;
 
-public class AttractiveSpell extends ShieldSpell implements ProjectileSpell, HomingSpell, TimedSpell {
+public class AttractiveSpell extends ShieldSpell implements HomingSpell, TimedSpell, ProjectileDelegate.EntityHitListener {
 
     private final EntityReference<Entity> target = new EntityReference<>();
 
@@ -140,10 +142,10 @@ public class AttractiveSpell extends ShieldSpell implements ProjectileSpell, Hom
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
         if (!isDead() && getTraits().get(Trait.CHAOS) > 0) {
             setDead();
-            Caster.of(entity).ifPresent(getTypeAndTraits()::apply);
+            Caster.of(hit.getEntity()).ifPresent(getTypeAndTraits()::apply);
         }
     }
 

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/CatapultSpell.java

@@ -5,18 +5,19 @@ import java.util.function.Consumer;
 import org.jetbrains.annotations.Nullable;
 
 import com.minelittlepony.unicopia.ability.magic.Caster;
-import com.minelittlepony.unicopia.ability.magic.spell.ProjectileSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.Trait;
 import com.minelittlepony.unicopia.mixin.MixinFallingBlockEntity;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.Trace;
 
-import net.minecraft.block.BlockState;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.FallingBlockEntity;
 import net.minecraft.predicate.entity.EntityPredicates;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
@@ -24,7 +25,7 @@ import net.minecraft.world.World;
 /**
  * Picks up and throws an entity or block.
  */
-public class CatapultSpell extends AbstractSpell implements ProjectileSpell {
+public class CatapultSpell extends AbstractSpell implements ProjectileDelegate.BlockHitListener, ProjectileDelegate.EntityHitListener {
     public static final SpellTraits DEFAULT_TRAITS = new SpellTraits.Builder()
             .with(Trait.FOCUS, 50)
             .with(Trait.KNOWLEDGE, 1)
@@ -40,16 +41,16 @@ public class CatapultSpell extends AbstractSpell implements ProjectileSpell {
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
+    public void onImpact(MagicProjectileEntity projectile, BlockHitResult hit) {
-        if (!projectile.isClient() && projectile.canModifyAt(pos)) {
+        if (!projectile.isClient() && projectile.canModifyAt(hit.getBlockPos())) {
-            createBlockEntity(projectile.world, pos, e -> apply(projectile, e));
+            createBlockEntity(projectile.world, hit.getBlockPos(), e -> apply(projectile, e));
         }
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
         if (!projectile.isClient()) {
-            apply(projectile, entity);
+            apply(projectile, hit.getEntity());
         }
     }
 

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/DarkVortexSpell.java

@@ -5,7 +5,6 @@ import org.jetbrains.annotations.Nullable;
 import com.minelittlepony.unicopia.USounds;
 import com.minelittlepony.unicopia.ability.magic.Affine;
 import com.minelittlepony.unicopia.ability.magic.Caster;
-import com.minelittlepony.unicopia.ability.magic.spell.ProjectileSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.Trait;
@@ -18,7 +17,6 @@ import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.MagicalDamageSource;
 import com.minelittlepony.unicopia.util.shape.Sphere;
 
-import net.minecraft.block.BlockState;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.FallingBlockEntity;
 import net.minecraft.entity.damage.DamageSource;
@@ -29,6 +27,8 @@ import net.minecraft.nbt.NbtCompound;
 import net.minecraft.particle.ParticleTypes;
 import net.minecraft.predicate.entity.EntityPredicates;
 import net.minecraft.sound.SoundCategory;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.explosion.Explosion.DestructionType;
@@ -40,7 +40,7 @@ import net.minecraft.world.explosion.Explosion.DestructionType;
  *  - Garbage bin
  *  - Link with a teleportation spell to create a wormhole
  */
-public class DarkVortexSpell extends AttractiveSpell implements ProjectileSpell {
+public class DarkVortexSpell extends AttractiveSpell implements ProjectileDelegate.BlockHitListener {
     public static final SpellTraits DEFAULT_TRAITS = new SpellTraits.Builder()
             .with(Trait.CHAOS, 5)
             .with(Trait.KNOWLEDGE, 1)
@@ -58,8 +58,9 @@ public class DarkVortexSpell extends AttractiveSpell implements ProjectileSpell
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
+    public void onImpact(MagicProjectileEntity projectile, BlockHitResult hit) {
         if (!projectile.isClient()) {
+            BlockPos pos = hit.getBlockPos();
             projectile.world.createExplosion(projectile, pos.getX(), pos.getY(), pos.getZ(), 3, DestructionType.NONE);
             toPlaceable().tick(projectile, Situation.BODY);
         }
@@ -212,8 +213,8 @@ public class DarkVortexSpell extends AttractiveSpell implements ProjectileSpell
 
             if (target instanceof MagicProjectileEntity projectile) {
                 Item item = projectile.getStack().getItem();
-                if (item instanceof ProjectileDelegate p && master != null) {
+                if (item instanceof ProjectileDelegate.EntityHitListener p && master != null) {
-                    p.onImpact(projectile, master);
+                    p.onImpact(projectile, new EntityHitResult(master));
                 }
             } else if (target instanceof PersistentProjectileEntity) {
                 if (master != null) {

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/FireBoltSpell.java

@@ -3,18 +3,21 @@ package com.minelittlepony.unicopia.ability.magic.spell.effect;
 import com.minelittlepony.unicopia.USounds;
 import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.HomingSpell;
-import com.minelittlepony.unicopia.ability.magic.spell.ProjectileSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.Trait;
 import com.minelittlepony.unicopia.entity.EntityReference;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
+
 import net.minecraft.entity.Entity;
 import net.minecraft.item.Items;
 import net.minecraft.nbt.NbtCompound;
 import net.minecraft.predicate.entity.EntityPredicates;
+import net.minecraft.util.hit.EntityHitResult;
 
-public class FireBoltSpell extends AbstractSpell implements ProjectileSpell, HomingSpell {
+public class FireBoltSpell extends AbstractSpell implements HomingSpell,
+        ProjectileDelegate.ConfigurationListener, ProjectileDelegate.EntityHitListener {
     public static final SpellTraits DEFAULT_TRAITS = new SpellTraits.Builder()
             .with(Trait.FOCUS, 10)
             .with(Trait.CHAOS, 1)
@@ -35,8 +38,8 @@ public class FireBoltSpell extends AbstractSpell implements ProjectileSpell, Hom
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
-        entity.setOnFireFor(90);
+        hit.getEntity().setOnFireFor(90);
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/FireSpell.java

@@ -6,12 +6,12 @@ import com.minelittlepony.unicopia.EquinePredicates;
 import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.AbstractAreaEffectSpell;
-import com.minelittlepony.unicopia.ability.magic.spell.ProjectileSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.SpellTraits;
 import com.minelittlepony.unicopia.ability.magic.spell.trait.Trait;
 import com.minelittlepony.unicopia.block.state.StateMaps;
 import com.minelittlepony.unicopia.particle.ParticleUtils;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.MagicalDamageSource;
 import com.minelittlepony.unicopia.util.VecHelper;
 import com.minelittlepony.unicopia.util.shape.Sphere;
@@ -29,6 +29,8 @@ import net.minecraft.particle.ParticleTypes;
 import net.minecraft.sound.SoundCategory;
 import net.minecraft.sound.SoundEvents;
 import net.minecraft.tag.BlockTags;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
@@ -37,7 +39,7 @@ import net.minecraft.world.explosion.Explosion.DestructionType;
 /**
  * Simple fire spell that triggers an effect when used on a block.
  */
-public class FireSpell extends AbstractAreaEffectSpell implements ProjectileSpell {
+public class FireSpell extends AbstractAreaEffectSpell implements ProjectileDelegate.BlockHitListener, ProjectileDelegate.EntityHitListener {
     public static final SpellTraits DEFAULT_TRAITS = new SpellTraits.Builder()
             .with(Trait.FIRE, 15)
             .build();
@@ -47,16 +49,18 @@ public class FireSpell extends AbstractAreaEffectSpell implements ProjectileSpel
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
+    public void onImpact(MagicProjectileEntity projectile, BlockHitResult hit) {
         if (!projectile.isClient()) {
-            projectile.getReferenceWorld().createExplosion(projectile.getEntity(), pos.getX(), pos.getY(), pos.getZ(), 2, DestructionType.DESTROY);
+            Vec3d pos = hit.getPos();
+            projectile.getReferenceWorld().createExplosion(projectile.getOwner(), pos.getX(), pos.getY(), pos.getZ(), 2, DestructionType.DESTROY);
         }
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
         if (!projectile.isClient()) {
-            projectile.getReferenceWorld().createExplosion(entity, entity.getX(), entity.getY(), entity.getZ(), 2, DestructionType.DESTROY);
+            Entity entity = hit.getEntity();
+            projectile.getReferenceWorld().createExplosion(projectile.getOwner(), entity.getX(), entity.getY(), entity.getZ(), 2, DestructionType.DESTROY);
         }
     }
 

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/ScorchSpell.java

@@ -7,6 +7,7 @@ import com.minelittlepony.unicopia.ability.magic.spell.trait.Trait;
 import com.minelittlepony.unicopia.block.state.StateMaps;
 import com.minelittlepony.unicopia.particle.MagicParticleEffect;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.PosHelper;
 import com.minelittlepony.unicopia.util.shape.Sphere;
 
@@ -14,7 +15,7 @@ import net.minecraft.particle.ParticleTypes;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 
-public class ScorchSpell extends FireSpell {
+public class ScorchSpell extends FireSpell implements ProjectileDelegate.ConfigurationListener {
     public static final SpellTraits DEFAULT_TRAITS = new SpellTraits.Builder()
             .with(Trait.FIRE, 10)
             .build();

src/main/java/com/minelittlepony/unicopia/ability/magic/spell/effect/TransformationSpell.java

@@ -9,10 +9,10 @@ import com.minelittlepony.unicopia.USounds;
 import com.minelittlepony.unicopia.UTags;
 import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
-import com.minelittlepony.unicopia.ability.magic.spell.ProjectileSpell;
 import com.minelittlepony.unicopia.entity.UEntities;
 import com.minelittlepony.unicopia.particle.ParticleUtils;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.Registries;
 
 import net.minecraft.entity.Entity;
@@ -21,12 +21,13 @@ import net.minecraft.entity.SpawnGroup;
 import net.minecraft.entity.mob.MobEntity;
 import net.minecraft.particle.ParticleTypes;
 import net.minecraft.util.Util;
+import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.world.World;
 
 /**
  * Transforms whatever entity it strikes into a random other entity.
  */
-public class TransformationSpell extends AbstractSpell implements ProjectileSpell {
+public class TransformationSpell extends AbstractSpell implements ProjectileDelegate.EntityHitListener {
     protected TransformationSpell(CustomisedSpellType<?> type) {
         super(type);
     }
@@ -37,10 +38,11 @@ public class TransformationSpell extends AbstractSpell implements ProjectileSpel
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
         if (projectile.world.isClient) {
             return;
         }
+        Entity entity = hit.getEntity();
         pickType(entity.getType(), entity.world).flatMap(type -> convert(entity, type)).ifPresentOrElse(e -> {
             entity.playSound(USounds.SPELL_TRANSFORM_TRANSMUTE_ENTITY, 1, 1);
         }, () -> {

src/main/java/com/minelittlepony/unicopia/item/FilledJarItem.java

@@ -21,6 +21,7 @@ import net.minecraft.particle.ParticleTypes;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.text.Text;
 import net.minecraft.util.ActionResult;
+import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.world.WorldEvents;
 
@@ -51,8 +52,10 @@ public class FilledJarItem extends JarItem implements ChameleonItem {
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
+    public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
-        super.onImpact(projectile, entity);
+        super.onImpact(projectile, hit);
+
+        Entity entity = hit.getEntity();
 
         if (!entity.isAttackable() || !(projectile instanceof FlyingItemEntity)) {
             return;
@@ -121,7 +124,7 @@ public class FilledJarItem extends JarItem implements ChameleonItem {
     }
 
     @Override
-    protected void onImpact(MagicProjectileEntity projectile) {
+    public void onImpact(MagicProjectileEntity projectile) {
         ItemStack stack = getAppearanceStack(projectile.getStack());
         stack.damage(1, projectile.world.random, null);
         projectile.dropStack(stack);

src/main/java/com/minelittlepony/unicopia/item/HeavyProjectileItem.java

@@ -6,8 +6,8 @@ import com.minelittlepony.unicopia.USounds;
 import com.minelittlepony.unicopia.UTags;
 import com.minelittlepony.unicopia.entity.PhysicsBodyProjectileEntity;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 
-import net.minecraft.block.BlockState;
 import net.minecraft.block.DispenserBlock;
 import net.minecraft.block.dispenser.ProjectileDispenserBehavior;
 import net.minecraft.entity.FlyingItemEntity;
@@ -16,12 +16,12 @@ import net.minecraft.entity.projectile.PersistentProjectileEntity;
 import net.minecraft.entity.projectile.ProjectileEntity;
 import net.minecraft.item.ItemStack;
 import net.minecraft.sound.SoundEvent;
-import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.hit.BlockHitResult;
 import net.minecraft.util.math.Position;
 import net.minecraft.world.GameRules;
 import net.minecraft.world.World;
 
-public class HeavyProjectileItem extends ProjectileItem {
+public class HeavyProjectileItem extends ProjectileItem implements ProjectileDelegate.BlockHitListener {
 
     public HeavyProjectileItem(Settings settings, float projectileDamage) {
         super(settings, projectileDamage);
@@ -52,13 +52,13 @@ public class HeavyProjectileItem extends ProjectileItem {
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
+    public void onImpact(MagicProjectileEntity projectile, BlockHitResult hit) {
         if (projectile.world.getGameRules().getBoolean(GameRules.DO_MOB_GRIEFING)) {
             float damage = projectile instanceof FlyingItemEntity ? getProjectileDamage(((FlyingItemEntity)projectile).getStack()) : 0;
 
             if (damage > 0 && projectile.world.random.nextInt(90) == 0) {
-                if (state.isIn(UTags.FRAGILE)) {
+                if (projectile.world.getBlockState(hit.getBlockPos()).isIn(UTags.FRAGILE)) {
-                    projectile.world.breakBlock(pos, true);
+                    projectile.world.breakBlock(hit.getBlockPos(), true);
                 }
             }
         }

src/main/java/com/minelittlepony/unicopia/item/JarItem.java

@@ -7,11 +7,10 @@ import com.minelittlepony.unicopia.entity.ItemImpl;
 import com.minelittlepony.unicopia.particle.ParticleUtils;
 import com.minelittlepony.unicopia.particle.UParticles;
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
+import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 
 import net.minecraft.block.Block;
-import net.minecraft.block.BlockState;
 import net.minecraft.block.Blocks;
-import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.ItemEntity;
 import net.minecraft.entity.LightningEntity;
@@ -20,13 +19,12 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.sound.SoundEvent;
 import net.minecraft.util.ActionResult;
-import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.ChunkSectionPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.Heightmap;
 import net.minecraft.world.WorldEvents;
 
-public class JarItem extends ProjectileItem implements ItemImpl.GroundTickCallback {
+public class JarItem extends ProjectileItem implements ItemImpl.GroundTickCallback, ProjectileDelegate.HitListener {
 
     private final boolean rain;
     private final boolean thunder;
@@ -82,16 +80,7 @@ public class JarItem extends ProjectileItem implements ItemImpl.GroundTickCallba
     }
 
     @Override
-    public void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {
+    public void onImpact(MagicProjectileEntity projectile) {
-        onImpact(projectile);
-    }
-
-    @Override
-    public void onImpact(MagicProjectileEntity projectile, Entity entity) {
-        onImpact(projectile);
-    }
-
-    protected void onImpact(MagicProjectileEntity projectile) {
         if (!projectile.world.isClient()) {
             ServerWorld world = (ServerWorld)projectile.world;
 

src/main/java/com/minelittlepony/unicopia/item/ProjectileItem.java

@@ -3,7 +3,6 @@ package com.minelittlepony.unicopia.item;
 import org.jetbrains.annotations.Nullable;
 
 import com.minelittlepony.unicopia.projectile.MagicProjectileEntity;
-import com.minelittlepony.unicopia.projectile.ProjectileDelegate;
 import com.minelittlepony.unicopia.util.SoundEmitter;
 
 import net.minecraft.entity.player.PlayerEntity;
@@ -17,7 +16,7 @@ import net.minecraft.util.Hand;
 import net.minecraft.util.TypedActionResult;
 import net.minecraft.world.World;
 
-abstract class ProjectileItem extends Item implements ProjectileDelegate {
+abstract class ProjectileItem extends Item {
 
     private final float projectileDamage;
 

src/main/java/com/minelittlepony/unicopia/projectile/MagicProjectileEntity.java

@@ -1,6 +1,8 @@
 package com.minelittlepony.unicopia.projectile;
 
+import java.util.Optional;
 import java.util.function.Consumer;
+import java.util.function.Function;
 
 import org.jetbrains.annotations.Nullable;
 
@@ -10,7 +12,6 @@ import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.Levelled;
 import com.minelittlepony.unicopia.ability.magic.SpellContainer;
 import com.minelittlepony.unicopia.ability.magic.SpellContainer.Operation;
-import com.minelittlepony.unicopia.ability.magic.SpellPredicate;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.entity.EntityPhysics;
@@ -273,7 +274,7 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
     protected void onBlockHit(BlockHitResult hit) {
         super.onBlockHit(hit);
 
-        forEachDelegates(effect -> effect.onImpact(this, hit.getBlockPos(), world.getBlockState(hit.getBlockPos())));
+        forEachDelegates(effect -> effect.onImpact(this, hit), ProjectileDelegate.BlockHitListener.PREDICATE);
     }
 
     @Override
@@ -291,20 +292,16 @@ public class MagicProjectileEntity extends ThrownItemEntity implements Caster<Li
                 entity.damage(DamageSource.thrownProjectile(this, getOwner()), getThrowDamage());
             }
 
-            forEachDelegates(effect -> effect.onImpact(this, entity));
+            forEachDelegates(effect -> effect.onImpact(this, hit), ProjectileDelegate.EntityHitListener.PREDICATE);
         }
     }
 
-    protected void forEachDelegates(Consumer<ProjectileDelegate> consumer) {
+    protected <T extends ProjectileDelegate> void forEachDelegates(Consumer<T> consumer, Function<Object, T> predicate) {
         getSpellSlot().forEach(spell -> {
-            if (SpellPredicate.HAS_PROJECTILE_EVENTS.test(spell)) {
+            Optional.ofNullable(predicate.apply(spell)).ifPresent(consumer);
-                consumer.accept((ProjectileDelegate)spell);
-            }
             return Operation.SKIP;
         }, world.isClient);
-        if (getItem().getItem() instanceof ProjectileDelegate) {
+        Optional.ofNullable(predicate.apply(getItem().getItem())).ifPresent(consumer);
-            consumer.accept(((ProjectileDelegate)getItem().getItem()));
-        }
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/projectile/ProjectileDelegate.java

@@ -1,17 +1,46 @@
 package com.minelittlepony.unicopia.projectile;
 
-import net.minecraft.block.BlockState;
+import java.util.function.Function;
-import net.minecraft.entity.Entity;
+
-import net.minecraft.util.math.BlockPos;
+import com.minelittlepony.unicopia.ability.magic.Caster;
+
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.hit.EntityHitResult;
 
 public interface ProjectileDelegate {
-    /**
+    interface ConfigurationListener extends ProjectileDelegate {
-     * Called once the projectile lands either hitting the ground or an entity.
+        Function<Object, ConfigurationListener> PREDICATE = a -> a instanceof ConfigurationListener ? (ConfigurationListener)a : null;
-     */
-    default void onImpact(MagicProjectileEntity projectile, BlockPos pos, BlockState state) {}
 
+        void configureProjectile(MagicProjectileEntity projectile, Caster<?> caster);
+    }
+
+    interface HitListener extends BlockHitListener, EntityHitListener {
+        @Override
+        default void onImpact(MagicProjectileEntity projectile, BlockHitResult hit) {
+            onImpact(projectile);
+        }
+
+        @Override
+        default void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
+            onImpact(projectile);
+        }
+
+        void onImpact(MagicProjectileEntity projectile);
+    }
+
+    interface BlockHitListener extends ProjectileDelegate {
+        Function<Object, BlockHitListener> PREDICATE = a -> a instanceof BlockHitListener ? (BlockHitListener)a : null;
         /**
          * Called once the projectile lands either hitting the ground or an entity.
          */
-    default void onImpact(MagicProjectileEntity projectile, Entity entity) {}
+        void onImpact(MagicProjectileEntity projectile, BlockHitResult hit);
+    }
+
+    interface EntityHitListener extends ProjectileDelegate {
+        Function<Object, EntityHitListener> PREDICATE = a -> a instanceof EntityHitListener ? (EntityHitListener)a : null;
+        /**
+         * Called once the projectile lands either hitting the ground or an entity.
+         */
+        void onImpact(MagicProjectileEntity projectile, EntityHitResult hit);
+    }
 }