Added caster utils to easily find magically enabled entities in the world, and make it easier to get out an effect of a given type

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

@@ -97,9 +97,9 @@ public class EntitySpell extends EntityLiving implements IMagicals, ICaster<Enti
 
 	@Nullable
 	@Override
-	public IMagicEffect getEffect(boolean update) {
-	    return effectDelegate.get(update);
-	}
+	public <T extends IMagicEffect> T getEffect(@Nullable Class<T> type, boolean update) {
+        return effectDelegate.get(type, update);
+    }
 
     @Override
     public boolean hasEffect() {

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

@@ -55,9 +55,14 @@ public class EffectSync<T extends EntityLivingBase> {
         return effect != null;
     }
 
-    public IMagicEffect get(boolean update) {
+    @SuppressWarnings("unchecked")
+    public <E extends IMagicEffect> E get(Class<E> type, boolean update) {
         if (!update) {
-            return effect;
+            if (effect == null || type == null || type.isAssignableFrom(effect.getClass())) {
+                return (E)effect;
+            }
+
+            return null;
         }
 
         NBTTagCompound comp = owned.getEntity().getDataManager().get(param);
@@ -82,7 +87,11 @@ public class EffectSync<T extends EntityLivingBase> {
             }
         }
 
-        return effect;
+        if (effect == null || type == null || type.isAssignableFrom(effect.getClass())) {
+            return (E)effect;
+        }
+
+        return null;
     }
 
     public void set(@Nullable IMagicEffect effect) {

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

@@ -369,8 +369,8 @@ class PlayerCapabilities implements IPlayer {
 
     @Nullable
     @Override
-    public IMagicEffect getEffect(boolean update) {
-        return effectDelegate.get(update);
+    public <T extends IMagicEffect> T getEffect(@Nullable Class<T> type, boolean update) {
+        return effectDelegate.get(type, update);
     }
 
     @Override

src/main/java/com/minelittlepony/unicopia/render/DisguiseRenderer.java

@@ -1,7 +1,6 @@
 package com.minelittlepony.unicopia.render;
 
 import com.minelittlepony.unicopia.player.IPlayer;
-import com.minelittlepony.unicopia.spell.IMagicEffect;
 import com.minelittlepony.unicopia.spell.SpellDisguise;
 
 import net.minecraft.client.Minecraft;
@@ -50,9 +49,9 @@ public class DisguiseRenderer {
     }
 
     public boolean renderDisguiseToGui(IPlayer player) {
-        IMagicEffect effect = player.getEffect(false);
+        SpellDisguise effect = player.getEffect(SpellDisguise.class, false);
 
-        if (!(effect instanceof SpellDisguise) || effect.getDead()) {
+        if (effect == null || effect.getDead()) {
             return false;
         }
 
@@ -63,7 +62,7 @@ public class DisguiseRenderer {
             return false;
         }
 
-        Entity e = ((SpellDisguise)effect).getDisguise();
+        Entity e = effect.getDisguise();
 
         // Check for a disguise and render it in our place.
         if (e != null) {

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

@@ -0,0 +1,69 @@
+package com.minelittlepony.unicopia.spell;
+
+import java.util.Optional;
+import java.util.stream.Stream;
+
+import javax.annotation.Nullable;
+
+import com.minelittlepony.unicopia.Predicates;
+import com.minelittlepony.unicopia.player.PlayerSpeciesList;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.util.math.AxisAlignedBB;
+import net.minecraft.util.math.BlockPos;
+
+public class CasterUtils {
+
+    public static Stream<ICaster<?>> findAllSpellsInRange(ICaster<?> source, double radius) {
+
+        BlockPos origin = source.getOrigin();
+
+        BlockPos begin = origin.add(-radius, -radius, -radius);
+        BlockPos end = origin.add(radius, radius, radius);
+
+        AxisAlignedBB bb = new AxisAlignedBB(begin, end);
+
+        return source.getWorld().getEntitiesInAABBexcluding(source.getEntity(), bb, e ->
+            !e.isDead && (e instanceof ICaster || e instanceof EntityPlayer)
+        ).stream().filter(e -> {
+                double dist = e.getDistance(origin.getX(), origin.getY(), origin.getZ());
+                double dist2 = e.getDistance(origin.getX(), origin.getY() - e.getEyeHeight(), origin.getZ());
+
+                return dist <= radius || dist2 <= radius;
+            })
+            .map(CasterUtils::toCaster)
+            .filter(o -> o.isPresent() && o.get() != source)
+            .map(Optional::get);
+    }
+
+    static Stream<ICaster<?>> findAllSpellsInRange(ICaster<?> source, AxisAlignedBB bb) {
+        return source.getWorld().getEntitiesInAABBexcluding(source.getEntity(), bb, e ->
+            !e.isDead && (e instanceof ICaster || Predicates.MAGI.test(e))
+        ).stream()
+            .map(CasterUtils::toCaster)
+            .filter(o -> o.isPresent() && o.get() != source)
+            .map(Optional::get);
+    }
+
+    @SuppressWarnings("unchecked")
+    static <T extends IMagicEffect> Optional<T> toMagicEffect(Class<T> type, @Nullable Entity entity) {
+        return toCaster(entity)
+                .filter(ICaster::hasEffect)
+                .map(caster -> caster.getEffect(type, false))
+                .filter(e -> !e.getDead());
+    }
+
+    static Optional<ICaster<?>> toCaster(@Nullable Entity entity) {
+
+        if (entity instanceof ICaster<?>) {
+            return Optional.of((ICaster<?>)entity);
+        }
+
+        if (entity instanceof EntityPlayer) {
+            return Optional.of(PlayerSpeciesList.instance().getPlayer((EntityPlayer)entity));
+        }
+
+        return Optional.empty();
+    }
+}

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

@@ -14,6 +14,7 @@ import com.minelittlepony.util.vector.VecHelper;
 
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
@@ -23,7 +24,12 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
     void setEffect(@Nullable IMagicEffect effect);
 
     @Nullable
-    IMagicEffect getEffect(boolean update);
+    default IMagicEffect getEffect(boolean update) {
+        return getEffect(null, update);
+    }
+
+    @Nullable
+    <T extends IMagicEffect> T getEffect(@Nullable Class<T> type, boolean update);
 
     @Nullable
     default IMagicEffect getEffect() {
@@ -39,14 +45,23 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
         return getOwner();
     }
 
+    /**
+     * Gets the unique id associated with this caste.
+     */
     default UUID getUniqueId() {
         return getEntity().getUniqueID();
     }
 
+    /**
+     * gets the minecraft world
+     */
     default World getWorld() {
         return getEntity().getEntityWorld();
     }
 
+    /**
+     * Gets the center position where this caster is located.
+     */
     default BlockPos getOrigin() {
         return getEntity().getPosition();
     }
@@ -69,6 +84,14 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
         }
     }
 
+    default Stream<ICaster<?>> findAllSpellsInRange(double radius) {
+        return CasterUtils.findAllSpellsInRange(this, radius);
+    }
+
+    default Stream<ICaster<?>> findAllSpellsInRange(AxisAlignedBB bb) {
+        return CasterUtils.findAllSpellsInRange(this, bb);
+    }
+
     default Stream<Entity> findAllEntitiesInRange(double radius) {
         return VecHelper.findAllEntitiesInRange(getEntity(), getWorld(), getOrigin(), radius);
     }

src/main/java/com/minelittlepony/util/vector/VecHelper.java

@@ -32,7 +32,7 @@ public class VecHelper {
         Vec3d pos = e.getPositionEyes(partialTicks);
         Vec3d look = e.getLook(partialTicks).scale(distance);
 
-        return e.world.rayTraceBlocks(pos, pos.add(look), false, false, true);
+        return e.getEntityWorld().rayTraceBlocks(pos, pos.add(look), false, false, true);
     }
 
     /**