Added the necromancy trap gem

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

@@ -51,12 +51,10 @@ public interface ICaster<E extends EntityLivingBase> extends IOwned<E>, ILevelle
     default void spawnParticles(IShape area, int count, Consumer<Vec3d> particleSpawner) {
         Random rand = getWorld().rand;
 
-        double x = getEntity().posX;
+        Vec3d pos = getOriginVector();
-        double y = getEntity().posY;
-        double z = getEntity().posZ;
 
         for (int i = 0; i < count; i++) {
-            particleSpawner.accept(area.computePoint(rand).add(x, y, z));
+            particleSpawner.accept(area.computePoint(rand).add(pos));
         }
     }
 

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

@@ -0,0 +1,118 @@
+package com.minelittlepony.unicopia.spell;
+
+import java.util.List;
+
+import com.google.common.collect.Lists;
+import com.minelittlepony.util.WorldEvent;
+import com.minelittlepony.util.shape.IShape;
+import com.minelittlepony.util.shape.Sphere;
+import com.minelittlepony.util.vector.VecHelper;
+
+import net.minecraft.entity.EntityCreature;
+import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.entity.monster.EntityHusk;
+import net.minecraft.entity.monster.EntityPigZombie;
+import net.minecraft.entity.monster.EntityZombie;
+import net.minecraft.util.EnumParticleTypes;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.world.EnumDifficulty;
+import net.minecraft.world.World;
+
+public class SpellNecromancy extends AbstractSpell {
+
+    private final List<IMonsterSpawn<?>> spawns = Lists.newArrayList(
+            EntityZombie::new,
+            EntityHusk::new,
+            EntityPigZombie::new
+    );
+
+    @Override
+    public String getName() {
+        return "necromancy";
+    }
+
+    @Override
+    public SpellAffinity getAffinity() {
+        return SpellAffinity.BAD;
+    }
+
+    @Override
+    public int getTint() {
+        return 0;
+    }
+
+    @Override
+    public boolean update(ICaster<?> source, int level) {
+
+        if (source.getWorld().isRemote || source.getWorld().getDifficulty() == EnumDifficulty.PEACEFUL) {
+            return true;
+        }
+
+
+        float additional = source.getWorld().getDifficultyForLocation(source.getOrigin()).getAdditionalDifficulty();
+
+        level++;
+
+        IShape affectRegion = new Sphere(false, level * 4);
+
+        if (source.getWorld().rand.nextInt(100) != 0) {
+            return true;
+        }
+
+        Vec3d origin = source.getOriginVector();
+
+        if (VecHelper.findAllEntitiesInRange(source.getEntity(), source.getWorld(), source.getOrigin(), level * 4)
+                .filter(e -> e instanceof EntityZombie)
+                .count() >= 10 * (1 + additional)) {
+            return true;
+        }
+
+        for (int i = 0; i < 10; i++) {
+            Vec3d pos = affectRegion.computePoint(source.getWorld().rand).add(origin);
+
+            BlockPos loc = new BlockPos(pos);
+
+            if (source.getWorld().isAirBlock(loc.up()) && !source.getWorld().isAirBlock(loc)) {
+                spawnMonster(source, pos);
+
+                return true;
+            }
+        }
+
+
+        return true;
+    }
+
+    protected void spawnMonster(ICaster<?> source, Vec3d pos) {
+        int index = (int)MathHelper.nextDouble(source.getWorld().rand, 0, spawns.size());
+        EntityLivingBase zombie = spawns.get(index).create(source.getWorld());
+        zombie.setPosition(pos.x, pos.y, pos.z);
+
+
+        if (zombie instanceof EntityCreature) {
+            ((EntityCreature)zombie).setHomePosAndDistance(source.getOrigin(), 10);
+        }
+        zombie.motionY += 0.3F;
+
+        source.getWorld().playEvent(WorldEvent.DOOR_BROKEN.getId(), zombie.getPosition(), 0);
+
+        source.getWorld().spawnEntity(zombie);
+    }
+
+    @Override
+    public void render(ICaster<?> source, int level) {
+        IShape affectRegion = new Sphere(false, (1 + level) * 4);
+
+        source.spawnParticles(affectRegion, 5, pos -> {
+            if (!source.getWorld().isAirBlock(new BlockPos(pos).down())) {
+                source.getWorld().spawnParticle(EnumParticleTypes.FLAME, pos.x, pos.y, pos.z, 0, 0, 0);
+            }
+        });
+    }
+
+    interface IMonsterSpawn<T extends EntityLivingBase> {
+        T create(World w);
+    }
+}

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

@@ -38,6 +38,7 @@ public class SpellRegistry {
         registerSpell(SpellPortal::new);
         registerSpell(SpellVortex::new);
         registerSpell(SpellDisguise::new);
+        registerSpell(SpellNecromancy::new);
     }
 
     @Nullable

src/main/resources/assets/unicopia/lang/en_US.lang

@@ -54,7 +54,7 @@ curse.shield.tagline=Hostility I
 curse.vortex.name=Suffering
 curse.vortex.tagline=Torture I
 
-curse.necromany.name=Necromancy
+curse.necromancy.name=Necromancy
 curse.necromancy.tagline=Resurrection I
 
 item.spellbook.name=Spellbook