Fix the displacement spell. Fixes #456

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

@@ -77,39 +77,38 @@ public class PlacementControlSpell extends AbstractSpell implements OrientedSpel
 
     @Override
     public boolean apply(Caster<?> caster) {
-        if (delegate == null) {
+        return delegate != null && super.apply(caster);
-            return false;
-        }
-        boolean result = super.apply(caster);
-        if (result) {
-            if (dimension.isEmpty()) {
-                setDimension(caster.asWorld().getRegistryKey());
-            }
-            if (position.isEmpty()) {
-                setPosition(caster.asEntity().getPos());
-            }
-            if (delegate instanceof PlacementDelegate) {
-                ((PlacementDelegate)delegate).onPlaced(caster, this);
-            }
-
-            CastSpellEntity entity = new CastSpellEntity(caster.asWorld(), caster, this);
-
-            Vec3d pos = position.get();
-            Vec3d rot = orientation.orElse(Vec3d.ZERO);
-
-            entity.updatePositionAndAngles(pos.x, pos.y, pos.z, (float)rot.y, (float)rot.x);
-            entity.getWorld().spawnEntity(entity);
-
-            placedEntityId = entity.getUuid();
-        }
-        return result;
     }
 
     @Override
     public boolean tick(Caster<?> source, Situation situation) {
-        if (!source.isClient() && getConnection(source) == null) {
+        if (!source.isClient()) {
-            setDead();
+
+            if (placedEntityId == null) {
+                if (dimension.isEmpty()) {
+                    setDimension(source.asWorld().getRegistryKey());
+                }
+                if (position.isEmpty()) {
+                    setPosition(source.asEntity().getPos());
+                }
+                System.out.println("Creating placed spell");
+                CastSpellEntity entity = new CastSpellEntity(source.asWorld(), source, this);
+
+                Vec3d pos = position.get();
+                Vec3d rot = orientation.orElse(Vec3d.ZERO);
+
+                entity.updatePositionAndAngles(pos.x, pos.y, pos.z, (float)rot.y, (float)rot.x);
+                entity.getWorld().spawnEntity(entity);
+
+                placedEntityId = entity.getUuid();
+                setDirty();
+            } else {
+                if (getConnection(source) == null) {
+                    setDead();
+                }
+            }
         }
+
         return !isDead();
     }
 

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

@@ -18,13 +18,13 @@ import net.minecraft.nbt.NbtCompound;
 import net.minecraft.util.hit.EntityHitResult;
 import net.minecraft.util.math.Vec3d;
 
-public class DisplacementSpell extends AbstractSpell implements HomingSpell, ProjectileDelegate.EntityHitListener {
+public class DisplacementSpell extends AbstractSpell implements HomingSpell, ProjectileDelegate.HitListener {
 
     private static final SpellAttribute<Float> DAMAGE_TO_TARGET = SpellAttribute.create(SpellAttributeType.DAMAGE_TO_TARGET, AttributeFormat.REGULAR, AttributeFormat.PERCENTAGE, Trait.BLOOD, blood -> blood);
 
     static final TooltipFactory TOOLTIP = DAMAGE_TO_TARGET;
 
-    private final EntityReference<Entity> target = new EntityReference<>();
+    private final EntityReference<Entity> target = dataTracker.startTracking(new EntityReference<>());
 
     private int ticks = 10;
 
@@ -34,7 +34,7 @@ public class DisplacementSpell extends AbstractSpell implements HomingSpell, Pro
 
     @Override
     public Spell prepareForCast(Caster<?> caster, CastingMethod method) {
-        return toPlaceable();
+        return method.isIndirectCause() ? this : toPlaceable();
     }
 
     @Override
@@ -43,14 +43,23 @@ public class DisplacementSpell extends AbstractSpell implements HomingSpell, Pro
 
         originator.asEntity().setGlowing(true);
 
+        if (situation == Situation.PROJECTILE) {
+            return !isDead();
+        }
+
         ticks--;
 
         if (originator.isClient()) {
             return !isDead() || ticks >= -10;
         }
 
-        if (ticks == 0) {
+        if (!originator.isClient()) {
-            target.ifPresent(originator.asWorld(), target -> apply(originator, target));
+            target.ifPresent(originator.asWorld(), target -> {
+                target.setGlowing(true);
+                if (ticks == 0) {
+                    apply(originator, target);
+                }
+            });
         }
 
         return ticks >= -10;
@@ -58,7 +67,18 @@ public class DisplacementSpell extends AbstractSpell implements HomingSpell, Pro
 
     @Override
     public void onImpact(MagicProjectileEntity projectile, EntityHitResult hit) {
-        Caster.of(projectile.getMaster()).ifPresent(originator -> apply(originator, hit.getEntity()));
+        HitListener.super.onImpact(projectile, hit);
+        Caster.of(projectile.getMaster()).ifPresent(originator -> {
+            apply(originator, hit.getEntity());
+        });
+    }
+
+    @Override
+    public void onImpact(MagicProjectileEntity projectile) {
+        if (projectile.getMaster() instanceof Entity owner) {
+            owner.setGlowing(false);
+        }
+        target.ifPresent(projectile.asWorld(), e -> e.setGlowing(false));
     }
 
     private void apply(Caster<?> originator, Entity target) {
@@ -107,11 +127,13 @@ public class DisplacementSpell extends AbstractSpell implements HomingSpell, Pro
     public void toNBT(NbtCompound compound) {
         super.toNBT(compound);
         compound.putInt("ticks", ticks);
+        compound.put("target", target.toNBT());
     }
 
     @Override
     public void fromNBT(NbtCompound compound) {
         super.fromNBT(compound);
         ticks = compound.getInt("ticks");
+        target.fromNBT(compound.getCompound("target"));
     }
 }

src/main/java/com/minelittlepony/unicopia/entity/mob/CastSpellEntity.java

@@ -11,6 +11,7 @@ import com.minelittlepony.unicopia.ability.magic.SpellSlots;
 import com.minelittlepony.unicopia.ability.magic.spell.PlacementControlSpell;
 import com.minelittlepony.unicopia.ability.magic.spell.Situation;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
+import com.minelittlepony.unicopia.ability.magic.spell.PlacementControlSpell.PlacementDelegate;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.entity.EntityPhysics;
 import com.minelittlepony.unicopia.entity.EntityReference;
@@ -70,8 +71,12 @@ public class CastSpellEntity extends LightEmittingEntity implements Caster<CastS
         this.controllingEntityUuid = caster.asEntity().getUuid();
         this.controllingSpellUuid = control.getUuid();
         setCaster(caster);
-        Spell spell = Spell.copy(control.getDelegate());
+
-        spells.getSlots().put(spell);
+        if (control.getDelegate() instanceof PlacementDelegate delegate) {
+            delegate.onPlaced(caster, control);
+        }
+
+        spells.getSlots().put(Spell.copy(control.getDelegate()));
     }
 
     public CastSpellEntity(EntityType<?> type, World world) {