Allow spells to animate post-removal

src/main/java/com/minelittlepony/unicopia/ability/UnicornDispellAbility.java

@@ -7,6 +7,7 @@ import com.minelittlepony.unicopia.InteractionManager;
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.ability.data.Pos;
 import com.minelittlepony.unicopia.ability.magic.Caster;
+import com.minelittlepony.unicopia.ability.magic.SpellContainer.Operation;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.client.render.PlayerPoser.Animation;
 import com.minelittlepony.unicopia.entity.player.Pony;
@@ -92,7 +93,11 @@ public class UnicornDispellAbility implements Ability<Pos> {
     public boolean apply(Pony player, Pos data) {
         player.setAnimation(Animation.WOLOLO, Animation.Recipient.ANYONE);
         Caster.stream(VecHelper.findInRange(player.asEntity(), player.asWorld(), data.vec(), 3, EquinePredicates.IS_PLACED_SPELL).stream()).forEach(target -> {
-            target.getSpellSlot().clear();
+            target.getSpellSlot().forEach(spell -> {
+                spell.setDead();
+                spell.tickDying(target);
+                return Operation.ofBoolean(!spell.isDead());
+            }, true);
         });
         return true;
     }

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

@@ -69,11 +69,20 @@ public abstract class AbstractDelegatingSpell implements Spell,
         getDelegates().forEach(Spell::setDead);
     }
 
+    @Override
+    public void tickDying(Caster<?> caster) {
+    }
+
     @Override
     public boolean isDead() {
         return getDelegates().isEmpty() || getDelegates().stream().allMatch(Spell::isDead);
     }
 
+    @Override
+    public boolean isDying() {
+        return false;
+    }
+
     @Override
     public boolean isDirty() {
         return dirty || getDelegates().stream().anyMatch(Spell::isDirty);
@@ -110,7 +119,13 @@ public abstract class AbstractDelegatingSpell implements Spell,
 
     @Override
     public boolean tick(Caster<?> source, Situation situation) {
-        return execute(getDelegates().stream(), a -> a.tick(source, situation));
+        return execute(getDelegates().stream(), a -> {
+            if (a.isDying()) {
+                a.tickDying(source);
+                return !a.isDead();
+            }
+            return a.tick(source, situation);
+        });
     }
 
     @Override

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

@@ -59,6 +59,10 @@ public class PlaceableSpell extends AbstractDelegatingSpell implements OrientedS
     private int prevAge;
     private int age;
 
+    private boolean dead;
+    private int prevDeathTicks;
+    private int deathTicks;
+
     private Optional<Vec3d> position = Optional.empty();
 
     public PlaceableSpell(CustomisedSpellType<?> type) {
@@ -74,6 +78,29 @@ public class PlaceableSpell extends AbstractDelegatingSpell implements OrientedS
         return MathHelper.lerp(tickDelta, prevAge, age);
     }
 
+    public float getScale(float tickDelta) {
+        float add = MathHelper.clamp(getAge(tickDelta) / 25F, 0, 1);
+        float subtract = dead ? 1 - (MathHelper.lerp(tickDelta, prevDeathTicks, deathTicks) / 20F) : 0;
+        return MathHelper.clamp(add - subtract, 0, 1);
+    }
+
+    @Override
+    public boolean isDying() {
+        return dead && deathTicks > 0;
+    }
+
+    @Override
+    public void setDead() {
+        super.setDead();
+        dead = true;
+        deathTicks = 20;
+    }
+
+    @Override
+    public boolean isDead() {
+        return dead && deathTicks <= 0;
+    }
+
     @Override
     public Collection<Spell> getDelegates() {
         return List.of(spell);
@@ -119,6 +146,12 @@ public class PlaceableSpell extends AbstractDelegatingSpell implements OrientedS
         return !isDead();
     }
 
+    @Override
+    public void tickDying(Caster<?> caster) {
+        prevDeathTicks = deathTicks;
+        deathTicks--;
+    }
+
     private void checkDetachment(Caster<?> source, EntityValues<?> target) {
         if (getWorld(source).map(Ether::get).map(ether -> ether.get(getType(), target, placedSpellId)).isEmpty()) {
             setDead();
@@ -198,6 +231,8 @@ public class PlaceableSpell extends AbstractDelegatingSpell implements OrientedS
     @Override
     public void toNBT(NbtCompound compound) {
         super.toNBT(compound);
+        compound.putBoolean("dead", dead);
+        compound.putInt("deathTicks", deathTicks);
         compound.putInt("age", age);
         compound.putFloat("pitch", pitch);
         compound.putFloat("yaw", yaw);
@@ -217,6 +252,8 @@ public class PlaceableSpell extends AbstractDelegatingSpell implements OrientedS
     @Override
     public void fromNBT(NbtCompound compound) {
         super.fromNBT(compound);
+        dead = compound.getBoolean("dead");
+        deathTicks = compound.getInt("deathTicks");
         age = compound.getInt("age");
         pitch = compound.getFloat("pitch");
         yaw = compound.getFloat("yaw");

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

@@ -61,6 +61,8 @@ public interface Spell extends NbtSerialisable, Affine {
      */
     boolean isDead();
 
+    boolean isDying();
+
     /**
      * Returns true if this effect has changes that need to be sent to the client.
      */
@@ -68,6 +70,7 @@ public interface Spell extends NbtSerialisable, Affine {
 
     /**
      * Applies this spell to the supplied caster.
+     * @param caster    The caster to apply the spell to
      */
     default boolean apply(Caster<?> caster) {
         caster.getSpellSlot().put(this);
@@ -76,7 +79,7 @@ public interface Spell extends NbtSerialisable, Affine {
 
     /**
      * Gets the default form of this spell used to apply to a caster.
-     * @param caster
+     * @param caster    The caster currently fueling this spell
      */
     default Spell prepareForCast(Caster<?> caster, CastingMethod method) {
         return this;
@@ -89,6 +92,12 @@ public interface Spell extends NbtSerialisable, Affine {
      */
     boolean tick(Caster<?> caster, Situation situation);
 
+    /**
+     * Called on spells that are actively dying to update any post-death animations before removal.
+     * @param caster    The caster currently fueling this spell
+     */
+    void tickDying(Caster<?> caster);
+
     /**
      * Marks this effect as dirty.
      */

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

@@ -12,6 +12,7 @@ import net.minecraft.nbt.NbtCompound;
 public abstract class AbstractSpell implements Spell {
 
     private boolean dead;
+    private boolean dying;
     private boolean dirty;
     private boolean hidden;
     private boolean destroyed;
@@ -45,7 +46,7 @@ public abstract class AbstractSpell implements Spell {
 
     @Override
     public final void setDead() {
-        dead = true;
+        dying = true;
         setDirty();
     }
 
@@ -54,6 +55,11 @@ public abstract class AbstractSpell implements Spell {
         return dead;
     }
 
+    @Override
+    public final boolean isDying() {
+        return dying;
+    }
+
     @Override
     public final boolean isDirty() {
         return dirty;
@@ -82,6 +88,11 @@ public abstract class AbstractSpell implements Spell {
     protected void onDestroyed(Caster<?> caster) {
     }
 
+    @Override
+    public void tickDying(Caster<?> caster) {
+        dead = true;
+    }
+
     @Override
     public final void destroy(Caster<?> caster) {
         if (destroyed) {
@@ -94,6 +105,7 @@ public abstract class AbstractSpell implements Spell {
 
     @Override
     public void toNBT(NbtCompound compound) {
+        compound.putBoolean("dying", dying);
         compound.putBoolean("dead", dead);
         compound.putBoolean("hidden", hidden);
         compound.putUuid("uuid", uuid);
@@ -106,6 +118,7 @@ public abstract class AbstractSpell implements Spell {
         if (compound.contains("uuid")) {
             uuid = compound.getUuid("uuid");
         }
+        dying = compound.getBoolean("dying");
         dead = compound.getBoolean("dead");
         hidden = compound.getBoolean("hidden");
         if (compound.contains("traits")) {

src/main/java/com/minelittlepony/unicopia/client/render/spell/PlacedSpellRenderer.java

@@ -57,7 +57,7 @@ public class PlacedSpellRenderer extends SpellRenderer<PlaceableSpell> {
         matrices.multiply(RotationAxis.POSITIVE_Y.rotationDegrees(180 - spell.yaw));
         matrices.multiply(RotationAxis.POSITIVE_X.rotationDegrees(90));
 
-        float scale = (spell.getAge(tickDelta) / 25F) * 3;
+        float scale = spell.getScale(tickDelta) * 3;
         matrices.scale(scale, scale, scale);
 
         float angle = (animationProgress / 9F) % 360;

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

@@ -72,6 +72,10 @@ public class CastSpellEntity extends LightEmittingEntity implements Caster<CastS
         }
     }
 
+    protected void updatePostDeath() {
+
+    }
+
     @Override
     public EntityReference<LivingEntity> getMasterReference() {
         return owner;

src/main/java/com/minelittlepony/unicopia/network/datasync/EffectSync.java

@@ -44,7 +44,13 @@ public class EffectSync implements SpellContainer, NbtSerialisable {
     }
 
     public boolean tick(Situation situation) {
-        return tick(spell -> Operation.ofBoolean(spell.tick(owner, situation)));
+        return tick(spell -> {
+            if (spell.isDying()) {
+                spell.tickDying(owner);
+                return Operation.ofBoolean(!spell.isDead());
+            }
+            return Operation.ofBoolean(spell.tick(owner, situation));
+        });
     }
 
     public boolean tick(Function<Spell, Operation> tickAction) {