Spells can now be attached to entities other than players

src/main/java/com/minelittlepony/unicopia/forgebullshit/FBS.java

@@ -1,8 +1,10 @@
 package com.minelittlepony.unicopia.forgebullshit;
 
 import com.minelittlepony.unicopia.Unicopia;
+import com.minelittlepony.unicopia.entity.IMagicals;
 
 import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.item.EntityItem;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.util.EnumFacing;
@@ -28,9 +30,11 @@ public class FBS {
 
     @SubscribeEvent
     public static void attach(AttachCapabilitiesEvent<Entity> event) {
-        if (event.getObject() instanceof EntityPlayer
-         || event.getObject() instanceof EntityItem) {
-            event.addCapability(new ResourceLocation("unicopia", "race"), new Provider(event.getObject()));
+        Entity obj = event.getObject();
+
+        if ((obj instanceof EntityLivingBase && !(obj instanceof IMagicals))
+         || obj instanceof EntityItem) {
+            event.addCapability(new ResourceLocation("unicopia", "race"), new Provider(obj));
         }
     }
 

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

@@ -6,7 +6,8 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import com.minelittlepony.unicopia.Predicates;
-import com.minelittlepony.unicopia.power.IPower;
+import com.minelittlepony.unicopia.player.IPlayer;
+import com.minelittlepony.unicopia.player.PlayerSpeciesList;
 import com.minelittlepony.unicopia.spell.CasterUtils;
 import com.minelittlepony.unicopia.spell.IAligned;
 import com.minelittlepony.unicopia.spell.ICaster;
@@ -82,12 +83,10 @@ public class ItemMagicStaff extends ItemStaff implements IAligned, ITossableItem
         if (attacker.isSneaking()) {
             stack.damageItem(50, attacker);
 
-            if (attacker instanceof EntityPlayer) {
-                IPower.takeFromPlayer((EntityPlayer)attacker, 4);
-            }
+            CasterUtils.toCaster(attacker).ifPresent(c -> c.subtractEnergyCost(4));
 
             onImpact(
-                    CasterUtils.toCaster(target).orElseGet(() -> CasterUtils.near(target)),
+                    CasterUtils.near(target),
                     target.getPosition(),
                     target.getEntityWorld().getBlockState(target.getPosition())
             );
@@ -140,9 +139,10 @@ public class ItemMagicStaff extends ItemStaff implements IAligned, ITossableItem
 
     @Override
     public void toss(World world, ItemStack stack, EntityPlayer player) {
-        CasterUtils.toCaster(player).ifPresent(effect::toss);
+        IPlayer iplayer = PlayerSpeciesList.instance().getPlayer(player);
 
-        IPower.takeFromPlayer(player, 4);
+        iplayer.subtractEnergyCost(4);
+        effect.toss(iplayer);
 
         stack.damageItem(1, player);
     }

src/main/java/com/minelittlepony/unicopia/player/EntityCapabilities.java

@@ -0,0 +1,135 @@
+package com.minelittlepony.unicopia.player;
+
+import java.util.Map;
+
+import com.google.common.collect.Maps;
+import com.minelittlepony.unicopia.Race;
+import com.minelittlepony.unicopia.network.EffectSync;
+import com.minelittlepony.unicopia.spell.IAligned;
+import com.minelittlepony.unicopia.spell.IAttachedEffect;
+import com.minelittlepony.unicopia.spell.ICaster;
+import com.minelittlepony.unicopia.spell.IMagicEffect;
+import com.minelittlepony.unicopia.spell.SpellAffinity;
+import com.minelittlepony.unicopia.spell.SpellRegistry;
+
+import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.nbt.NBTTagCompound;
+import net.minecraft.network.datasync.DataParameter;
+import net.minecraft.network.datasync.DataSerializers;
+import net.minecraft.network.datasync.EntityDataManager;
+
+public class EntityCapabilities implements IRaceContainer<EntityLivingBase>, ICaster<EntityLivingBase> {
+
+    private static final Map<Class<? extends EntityLivingBase>, DataParameter<NBTTagCompound>> EFFECT_KEYS = Maps.newHashMap();
+
+    private final DataParameter<NBTTagCompound> EFFECT;
+
+    private final EffectSync<EntityLivingBase> effectDelegate;
+
+    private EntityLivingBase entity;
+
+    EntityCapabilities(EntityLivingBase entity) {
+        setOwner(entity);
+
+        EFFECT = EFFECT_KEYS.computeIfAbsent(entity.getClass(), c -> {
+            return EntityDataManager.createKey(c, DataSerializers.COMPOUND_TAG);
+        });
+        effectDelegate = new EffectSync<>(this, EFFECT);
+
+        entity.getDataManager().register(EFFECT, new NBTTagCompound());
+    }
+
+    @Override
+    public Race getPlayerSpecies() {
+        return Race.HUMAN;
+    }
+
+    @Override
+    public void setPlayerSpecies(Race race) {
+    }
+
+    @Override
+    public void setEffect(IMagicEffect effect) {
+        effectDelegate.set(effect);
+    }
+
+    @Override
+    public <T extends IMagicEffect> T getEffect(Class<T> type, boolean update) {
+        return effectDelegate.get(type, update);
+    }
+
+    @Override
+    public boolean hasEffect() {
+        return effectDelegate.has();
+    }
+
+    @Override
+    public void beforeUpdate() {
+
+    }
+
+    @Override
+    public void onUpdate() {
+        if (hasEffect()) {
+            IAttachedEffect effect = getEffect(IAttachedEffect.class, true);
+
+            if (effect != null) {
+                if (entity.getEntityWorld().isRemote) {
+                    effect.renderOnPerson(this);
+                }
+
+                if (!effect.updateOnPerson(this)) {
+                    setEffect(null);
+                }
+            }
+        }
+    }
+
+    @Override
+    public void onDimensionalTravel(int destinationDimension) {
+
+    }
+
+    @Override
+    public void setOwner(EntityLivingBase owner) {
+        entity = owner;
+    }
+
+    @Override
+    public EntityLivingBase getOwner() {
+        return entity;
+    }
+
+    @Override
+    public int getCurrentLevel() {
+        return 0;
+    }
+
+    @Override
+    public void setCurrentLevel(int level) {
+    }
+
+    @Override
+    public SpellAffinity getAffinity() {
+        if (getOwner() instanceof IAligned) {
+            return ((IAligned)getOwner()).getAffinity();
+        }
+        return SpellAffinity.NEUTRAL;
+    }
+
+    @Override
+    public void writeToNBT(NBTTagCompound compound) {
+        IMagicEffect effect = getEffect();
+
+        if (effect != null) {
+            compound.setTag("effect", SpellRegistry.instance().serializeEffectToNBT(effect));
+        }
+    }
+
+    @Override
+    public void readFromNBT(NBTTagCompound compound) {
+        if (compound.hasKey("effect")) {
+            setEffect(SpellRegistry.instance().createEffectFromNBT(compound.getCompoundTag("effect")));
+        }
+    }
+}

src/main/java/com/minelittlepony/unicopia/player/Hooks.java

@@ -9,7 +9,7 @@ import net.minecraft.util.math.RayTraceResult;
 import net.minecraftforge.event.entity.ProjectileImpactEvent;
 import net.minecraftforge.event.entity.item.ItemTossEvent;
 import net.minecraftforge.event.entity.living.LivingEntityUseItemEvent;
-import net.minecraftforge.event.entity.living.LivingEvent.LivingJumpEvent;
+import net.minecraftforge.event.entity.living.LivingEvent;
 import net.minecraftforge.event.entity.player.PlayerDropsEvent;
 import net.minecraftforge.event.entity.player.PlayerEvent;
 import net.minecraftforge.event.entity.player.PlayerFlyableFallEvent;
@@ -31,7 +31,12 @@ class Hooks {
     }
 
     @SubscribeEvent
-    public static void onPlayerJump(LivingJumpEvent event) {
+    public static void onLivingUpdate(LivingEvent.LivingUpdateEvent event) {
+        PlayerSpeciesList.instance().getEntity(event.getEntityLiving()).onUpdate();
+    }
+
+    @SubscribeEvent
+    public static void onPlayerJump(LivingEvent.LivingJumpEvent event) {
         if (event.getEntityLiving() instanceof EntityPlayer) {
             if (PlayerSpeciesList.instance().getPlayer((EntityPlayer)event.getEntityLiving()).getGravity().getGravitationConstant() < 0) {
                 event.getEntityLiving().motionY = -event.getEntityLiving().motionY;

src/main/java/com/minelittlepony/unicopia/player/PlayerCapabilities.java

@@ -37,6 +37,7 @@ import net.minecraft.network.datasync.EntityDataManager;
 import net.minecraft.network.play.server.SPacketSetPassengers;
 import net.minecraft.potion.PotionEffect;
 import net.minecraft.stats.StatList;
+import net.minecraft.util.DamageSource;
 import net.minecraft.util.EnumHand;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockPos;
@@ -310,6 +311,22 @@ class PlayerCapabilities implements IPlayer {
         return true;
     }
 
+    @Override
+    public boolean subtractEnergyCost(double foodSubtract) {
+        if (!entity.capabilities.isCreativeMode) {
+            int food = (int)(entity.getFoodStats().getFoodLevel() - foodSubtract);
+
+            if (food < 0) {
+                entity.getFoodStats().addStats(-entity.getFoodStats().getFoodLevel(), 0);
+                entity.attackEntityFrom(DamageSource.MAGIC, -food/2);
+            } else {
+                entity.getFoodStats().addStats((int)-foodSubtract, 0);
+            }
+        }
+
+        return entity.getHealth() > 0;
+    }
+
     @Override
     public boolean stepOnCloud() {
         EntityPlayer player = getOwner();

src/main/java/com/minelittlepony/unicopia/player/PlayerSpeciesList.java

@@ -7,8 +7,10 @@ import javax.annotation.Nullable;
 import com.minelittlepony.unicopia.Race;
 import com.minelittlepony.unicopia.UConfig;
 import com.minelittlepony.unicopia.forgebullshit.FBS;
+import com.minelittlepony.unicopia.spell.ICaster;
 
 import net.minecraft.entity.Entity;
+import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.item.EntityItem;
 import net.minecraft.entity.player.EntityPlayer;
 
@@ -65,6 +67,10 @@ public class PlayerSpeciesList {
             return new ItemCapabilities();
         }
 
+        if (entity instanceof EntityLivingBase) {
+            return new EntityCapabilities((EntityLivingBase)entity);
+        }
+
         throw new IllegalArgumentException("entity");
     }
 
@@ -82,6 +88,12 @@ public class PlayerSpeciesList {
         return getPlayer(IPlayer.getPlayerFromServer(playerId));
     }
 
+    @SuppressWarnings("unchecked")
+    @Nullable
+    public <T extends EntityLivingBase> ICaster<T> getCaster(T entity) {
+        return (ICaster<T>)getEntity(entity);
+    }
+
     public <T extends Entity> IRaceContainer<T> getEntity(T entity) {
         return FBS.of(entity).getRaceContainer();
     }

src/main/java/com/minelittlepony/unicopia/power/IPower.java

@@ -10,38 +10,11 @@ import com.minelittlepony.util.shape.IShape;
 import com.minelittlepony.util.shape.Sphere;
 
 import net.minecraft.entity.Entity;
-import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.util.DamageSource;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 
 public interface IPower<T extends IData> extends IKeyBind {
 
-    /**
-     * Subtracts a given food amount from the player.
-     * Harms the player if there is not enough hunger available.
-     */
-    static boolean takeFromPlayer(EntityPlayer player, double foodSubtract) {
-        if (!player.capabilities.isCreativeMode) {
-            int food = (int)(player.getFoodStats().getFoodLevel() - foodSubtract);
-            if (food < 0) {
-                player.getFoodStats().addStats(-player.getFoodStats().getFoodLevel(), 0);
-                player.attackEntityFrom(DamageSource.MAGIC, -food/2);
-            } else {
-                player.getFoodStats().addStats((int)-foodSubtract, 0);
-            }
-        }
-
-        return player.getHealth() > 0;
-    }
-
-    static double getPlayerEyeYPos(EntityPlayer player) {
-        if (player.getEntityWorld().isRemote) {
-            return player.posY + player.getEyeHeight() - player.getYOffset();
-        }
-        return player.posY + player.getEyeHeight() - 1;
-    }
-
     static void spawnParticles(int particleId, Entity entity, int count, int...args) {
         double halfDist = entity.getEyeHeight() / 1.5;
         double middle = entity.getEntityBoundingBox().minY + halfDist;

src/main/java/com/minelittlepony/unicopia/power/PowerGrow.java

@@ -74,7 +74,7 @@ public class PowerGrow implements IPower<Location> {
         }
 
         if (count > 0) {
-            IPower.takeFromPlayer(player.getOwner(), count * 5);
+            player.subtractEnergyCost(count * 5);
         }
     }
 

src/main/java/com/minelittlepony/unicopia/power/PowerStomp.java

@@ -166,13 +166,13 @@ public class PowerStomp implements IPower<PowerStomp.Data> {
                 spawnParticleRing(player, i);
             }
 
-            IPower.takeFromPlayer(player, rad);
+            iplayer.subtractEnergyCost(rad);
         } else if (data.hitType == 1) {
 
             boolean harmed = player.getHealth() < player.getMaxHealth();
 
             if (harmed && player.world.rand.nextInt(30) == 0) {
-                IPower.takeFromPlayer(player, 3);
+                iplayer.subtractEnergyCost(3);
                 return;
             }
 
@@ -182,12 +182,12 @@ public class PowerStomp implements IPower<PowerStomp.Data> {
                     UWorld.enqueueTask(w -> removeTree(w, data.pos()));
                 }
 
-                IPower.takeFromPlayer(player, 3);
+                iplayer.subtractEnergyCost(3);
             } else {
                 int cost = dropApples(player.world, data.pos());
 
                 if (cost > 0) {
-                    IPower.takeFromPlayer(player, cost * 3);
+                    iplayer.subtractEnergyCost(cost * 3);
                 }
             }
         }

src/main/java/com/minelittlepony/unicopia/power/PowerTeleport.java

@@ -128,7 +128,7 @@ public class PowerTeleport implements IPower<Location> {
         }
 
         player.setPositionAndUpdate(data.x + (player.posX - Math.floor(player.posX)), data.y, data.z + (player.posZ - Math.floor(player.posZ)));
-        IPower.takeFromPlayer(player, distance);
+        iplayer.subtractEnergyCost(distance);
 
         player.fallDistance /= distance;
 

src/main/java/com/minelittlepony/unicopia/spell/CasterUtils.java

@@ -9,6 +9,7 @@ import javax.annotation.Nullable;
 import com.google.common.collect.Streams;
 import com.minelittlepony.unicopia.Predicates;
 import com.minelittlepony.unicopia.entity.EntitySpell;
+import com.minelittlepony.unicopia.entity.IMagicals;
 import com.minelittlepony.unicopia.player.PlayerSpeciesList;
 
 import net.minecraft.entity.Entity;
@@ -19,6 +20,9 @@ import net.minecraft.util.math.BlockPos;
 
 public class CasterUtils {
 
+    /**
+     * Finds all surrounding spells withing range from the given caster.
+     */
     public static Stream<ICaster<?>> findAllSpellsInRange(ICaster<?> source, double radius) {
 
         BlockPos origin = source.getOrigin();
@@ -41,6 +45,9 @@ public class CasterUtils {
             .map(Optional::get);
     }
 
+    /**
+     * Finds all magically capabable entities in the world.
+     */
     static Stream<ICaster<?>> findAllSpells(ICaster<?> source) {
         return source.getWorld().getEntities(EntityLivingBase.class, e -> {
             return e instanceof ICaster || e instanceof EntityPlayer;
@@ -67,29 +74,50 @@ public class CasterUtils {
                 .filter(e -> !e.getDead());
     }
 
+    /**
+     * Determines if the passed in entity is holding the named effect.
+     * By holding that meant the effect must be attached to the caster associated with the entity.
+     */
     public static boolean isHoldingEffect(String effectName, Entity entity) {
         return Streams.stream(entity.getEquipmentAndArmor())
             .map(SpellRegistry::getKeyFromStack)
             .anyMatch(s -> s.equals(effectName));
     }
 
+    /**
+     * Creates a new caster at the position of the given entity.
+     * First attempts to convert the passed entity into a caster.
+     */
+    @Nonnull
     public static ICaster<?> near(@Nonnull Entity entity) {
+        ICaster<?> result = toCasterRaw(entity);
+
+        if (result != null) {
+            return result;
+        }
+
         EntitySpell caster = new EntitySpell(entity.world);
         caster.copyLocationAndAnglesFrom(entity);
 
         return caster;
     }
 
+    /**
+     * Attempts to convert the passed entity into a caster using all the known methods.
+     */
     public static Optional<ICaster<?>> toCaster(@Nullable Entity entity) {
+        return Optional.ofNullable(toCasterRaw(entity));
+    }
 
+    private static ICaster<?> toCasterRaw(Entity entity) {
         if (entity instanceof ICaster<?>) {
-            return Optional.of((ICaster<?>)entity);
+            return (ICaster<?>)entity;
         }
 
-        if (entity instanceof EntityPlayer) {
-            return Optional.of(PlayerSpeciesList.instance().getPlayer((EntityPlayer)entity));
+        if (entity instanceof EntityLivingBase && !(entity instanceof IMagicals)) {
+            return PlayerSpeciesList.instance().getCaster((EntityLivingBase)entity);
         }
 
-        return Optional.empty();
+        return null;
     }
 }

src/main/java/com/minelittlepony/unicopia/spell/IAttachedEffect.java

@@ -1,7 +1,5 @@
 package com.minelittlepony.unicopia.spell;
 
-import com.minelittlepony.unicopia.player.IPlayer;
-
 public interface IAttachedEffect extends IMagicEffect {
     /**
      * Called every tick when attached to a player.
@@ -9,7 +7,7 @@ public interface IAttachedEffect extends IMagicEffect {
      * @param source    The entity we are currently attached to.
      * @return true to keep alive
      */
-    boolean updateOnPerson(IPlayer caster);
+    boolean updateOnPerson(ICaster<?> caster);
 
     /**
      * Called every tick when attached to a player. Used to apply particle effects.
@@ -17,5 +15,5 @@ public interface IAttachedEffect extends IMagicEffect {
      *
      * @param source    The entity we are currently attached to.
      */
-    default void renderOnPerson(IPlayer source) {}
+    default void renderOnPerson(ICaster<?> source) {}
 }

src/main/java/com/minelittlepony/unicopia/spell/ICaster.java

@@ -8,6 +8,7 @@ import java.util.stream.Stream;
 import javax.annotation.Nullable;
 
 import com.minelittlepony.unicopia.entity.EntitySpell;
+import com.minelittlepony.unicopia.entity.IMagicals;
 import com.minelittlepony.unicopia.player.IOwned;
 import com.minelittlepony.unicopia.power.IPower;
 import com.minelittlepony.util.shape.IShape;
@@ -15,28 +16,45 @@ import com.minelittlepony.util.vector.VecHelper;
 
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.util.DamageSource;
 import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 
-public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelled, IAligned {
+/**
+ * Interface for any magically capable entities that can cast and persist spells.
+ */
+public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelled, IAligned, IMagicals {
 
     void setEffect(@Nullable IMagicEffect effect);
 
+    /**
+     * Gets the active effect for this caster.
+     */
     @Nullable
     default IMagicEffect getEffect(boolean update) {
         return getEffect(null, update);
     }
 
+    /**
+     * Gets the active effect for the matching given type.
+     * Returns null if no such effect exists for this caster.
+     */
     @Nullable
     <T extends IMagicEffect> T getEffect(@Nullable Class<T> type, boolean update);
 
+    /**
+     * Gets the active effect for this caster updating it if needed.
+     */
     @Nullable
     default IMagicEffect getEffect() {
         return getEffect(true);
     }
 
+    /**
+     * Returns true if this caster has an active effect attached to it.
+     */
     boolean hasEffect();
 
     /**
@@ -81,6 +99,17 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
         return getEntity().getPosition();
     }
 
+    /**
+     * Gets the center position where this caster is located.
+     */
+    default Vec3d getOriginVector() {
+        return getEntity().getPositionVector();
+    }
+
+    /**
+     * Returns a new caster at the given position.
+     * This one is not altered, rather the method will return an entirely new caster with the same owner as this one.
+     */
     default ICaster<?> at(BlockPos newOrigin) {
         EntitySpell spell = new EntitySpell(getWorld());
         spell.setPosition(newOrigin.getX(), newOrigin.getY(), newOrigin.getZ());
@@ -89,10 +118,6 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
         return spell;
     }
 
-    default Vec3d getOriginVector() {
-        return getEntity().getPositionVector();
-    }
-
     default void spawnParticles(int particleId, int count, int...args) {
         IPower.spawnParticles(particleId, getEntity(), count, args);
     }
@@ -107,6 +132,12 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
         }
     }
 
+    default boolean subtractEnergyCost(double amount) {
+        getOwner().attackEntityFrom(DamageSource.MAGIC, (int)amount/2);
+
+        return getOwner().getHealth() > 0;
+    }
+
     default Stream<ICaster<?>> findAllSpells() {
         return CasterUtils.findAllSpells(this);
     }

src/main/java/com/minelittlepony/unicopia/spell/IDispenceable.java

@@ -6,7 +6,6 @@ import net.minecraft.util.EnumFacing;
 
 /**
  * Represents an object with an action to perform when dispensed from a dispenser.
- *
  */
 public interface IDispenceable extends IMagicEffect {
 

src/main/java/com/minelittlepony/unicopia/spell/SpellChangelingTrap.java

@@ -1,12 +1,13 @@
 package com.minelittlepony.unicopia.spell;
 
+import com.minelittlepony.unicopia.entity.IMagicals;
 import com.minelittlepony.unicopia.init.UBlocks;
 import com.minelittlepony.unicopia.init.USounds;
-import com.minelittlepony.unicopia.player.IPlayer;
 import com.minelittlepony.unicopia.player.PlayerSpeciesList;
 import com.minelittlepony.util.WorldEvent;
 
 import net.minecraft.block.state.IBlockState;
+import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.init.Blocks;
 import net.minecraft.init.Items;
@@ -51,9 +52,14 @@ public class SpellChangelingTrap extends AbstractSpell implements ITossedEffect,
         return new ItemStack(Items.SLIME_BALL);
     }
 
+    private boolean checkStruggleCondition(ICaster<?> caster) {
+        return !caster.getOrigin().equals(previousTrappedPosition)
+            || (!(caster.getOwner() instanceof EntityPlayer) && caster.getWorld().rand.nextInt(20) == 0);
+    }
+
     @Override
-    public boolean updateOnPerson(IPlayer caster) {
-        EntityPlayer entity = caster.getOwner();
+    public boolean updateOnPerson(ICaster<?> caster) {
+        EntityLivingBase entity = caster.getOwner();
 
         if (entity.motionY > 0) {
             entity.playSound(SoundEvents.BLOCK_SLIME_HIT, 1, 1);
@@ -67,15 +73,13 @@ public class SpellChangelingTrap extends AbstractSpell implements ITossedEffect,
             setDirty(true);
         }
 
-        if (!caster.getWorld().isRemote) {
-            if (!origin.equals(previousTrappedPosition)) {
+        if (!caster.getWorld().isRemote && checkStruggleCondition(caster)) {
             previousTrappedPosition = origin;
             struggleCounter--;
             WorldEvent.DESTROY_BLOCK.play(caster.getWorld(), origin, Blocks.SLIME_BLOCK.getDefaultState());
 
             setDirty(true);
         }
-        }
 
         if (caster.getWorld().isAirBlock(origin) || caster.getWorld().getBlockState(origin).getBlock().isReplaceable(caster.getWorld(), origin)) {
             caster.getWorld().setBlockState(origin, UBlocks.slime_layer.getDefaultState());
@@ -97,7 +101,10 @@ public class SpellChangelingTrap extends AbstractSpell implements ITossedEffect,
         entity.hurtTime = 2;
         entity.collidedHorizontally = true;
         entity.collided = true;
-        entity.capabilities.isFlying = false;
+
+        if (entity instanceof EntityPlayer) {
+            ((EntityPlayer)entity).capabilities.isFlying = false;
+        }
 
         PotionEffect SLIME_REGEN = new PotionEffect(MobEffects.REGENERATION, 0);
 
@@ -126,7 +133,7 @@ public class SpellChangelingTrap extends AbstractSpell implements ITossedEffect,
     }
 
     @Override
-    public void renderOnPerson(IPlayer source) {
+    public void renderOnPerson(ICaster<?> source) {
         render(source);
     }
 
@@ -140,7 +147,7 @@ public class SpellChangelingTrap extends AbstractSpell implements ITossedEffect,
         setDirty(true);
     }
 
-    protected void entrap(IPlayer e) {
+    protected void entrap(ICaster<?> e) {
 
         SpellChangelingTrap existing = e.getEffect(SpellChangelingTrap.class, true);
 
@@ -155,8 +162,8 @@ public class SpellChangelingTrap extends AbstractSpell implements ITossedEffect,
     public void onImpact(ICaster<?> caster, BlockPos pos, IBlockState state) {
         if (caster.isLocal()) {
             caster.findAllEntitiesInRange(5)
-                .filter(e -> e instanceof EntityPlayer)
-                .map(e -> PlayerSpeciesList.instance().getPlayer((EntityPlayer)e))
+                .filter(e -> !(e instanceof IMagicals) && e instanceof EntityLivingBase)
+                .map(e -> PlayerSpeciesList.instance().getCaster((EntityLivingBase)e))
                 .forEach(this::entrap);
         }
     }

src/main/java/com/minelittlepony/unicopia/spell/SpellDisguise.java

@@ -146,8 +146,6 @@ public class SpellDisguise extends AbstractSpell implements IAttachedEffect, ISu
         entity.setUniqueId(UUID.randomUUID());
         entity.extinguish();
 
-        PlayerSpeciesList.instance().getPlayer((EntityPlayer)entity).setEffect(null);
-
         onEntityLoaded(source);
     }
 
@@ -179,6 +177,8 @@ public class SpellDisguise extends AbstractSpell implements IAttachedEffect, ISu
             return;
         }
 
+        CasterUtils.toCaster(entity).ifPresent(c -> c.setEffect(null));
+
         if (source.getWorld().isRemote) {
             source.getWorld().spawnEntity(entity);
         }
@@ -289,7 +289,7 @@ public class SpellDisguise extends AbstractSpell implements IAttachedEffect, ISu
     }
 
     @Override
-    public boolean updateOnPerson(IPlayer caster) {
+    public boolean updateOnPerson(ICaster<?> caster) {
         return update(caster);
     }
 

src/main/java/com/minelittlepony/unicopia/spell/SpellShield.java

@@ -9,7 +9,6 @@ import com.minelittlepony.unicopia.particle.ParticleConnection;
 import com.minelittlepony.unicopia.particle.Particles;
 import com.minelittlepony.unicopia.player.IPlayer;
 import com.minelittlepony.unicopia.player.PlayerSpeciesList;
-import com.minelittlepony.unicopia.power.IPower;
 import com.minelittlepony.util.ProjectileUtil;
 import com.minelittlepony.util.shape.Sphere;
 
@@ -39,7 +38,7 @@ public class SpellShield extends AbstractSpell.RangedAreaSpell implements IAttac
     }
 
     @Override
-    public void renderOnPerson(IPlayer source) {
+    public void renderOnPerson(ICaster<?> source) {
         render(source);
     }
 
@@ -57,7 +56,7 @@ public class SpellShield extends AbstractSpell.RangedAreaSpell implements IAttac
     }
 
     @Override
-    public boolean updateOnPerson(IPlayer source) {
+    public boolean updateOnPerson(ICaster<?> source) {
         int costMultiplier = applyEntities(source);
         if (costMultiplier > 0) {
             if (source.getOwner().ticksExisted % 20 == 0) {
@@ -66,7 +65,7 @@ public class SpellShield extends AbstractSpell.RangedAreaSpell implements IAttac
                 cost *= costMultiplier / 5F;
                 System.out.println("Taking " + cost);
 
-                if (!IPower.takeFromPlayer(source.getOwner(), cost)) {
+                if (!source.subtractEnergyCost(cost)) {
                     setDead();
                 }
             }