Early working ritual using a snow block & crash fixes

src/main/java/dev/hytalemodding/RitualSpawner.java

@@ -1,13 +1,23 @@
 package dev.hytalemodding;
 
+import com.hypixel.hytale.math.vector.Rotation3f;
 import com.hypixel.hytale.server.core.universe.world.World;
+import com.hypixel.hytale.server.npc.NPCPlugin;
+import org.joml.Vector3d;
 import org.joml.Vector3i;
+import java.util.Objects;
 
 public class RitualSpawner {
     public void blockChangeEvent(String itemId, Vector3i targetPosition, World world) {
-        String blockId = world.getBlockType(targetPosition).getId();
+        String blockId = Objects.requireNonNull(world.getBlockType(targetPosition)).getId();
         RitualPlugin.LOGGER.atInfo().log(
                 "a block got placed or removed at the position: %d - %d - %d with the block id: %s and with the item id in hand: %s",
                 targetPosition.x, targetPosition.y, targetPosition.z, blockId, itemId);
+        if (itemId.compareTo("Soil_Snow") == 0 && blockId.compareTo("Empty") == 0) {
+            RitualPlugin.LOGGER.atInfo().log("Ritual complete");
+            world.execute(() -> {
+                NPCPlugin.get().spawnNPC(world.getEntityStore().getStore(), "Yeti", null, new Vector3d(targetPosition), new Rotation3f(0, 0, 0));
+            });
+        }
     }
 }

src/main/java/dev/hytalemodding/events/RitualBreakBlockEvent.java

@@ -7,6 +7,7 @@ import com.hypixel.hytale.component.Store;
 import com.hypixel.hytale.component.query.Query;
 import com.hypixel.hytale.component.system.EntityEventSystem;
 import com.hypixel.hytale.server.core.event.events.ecs.BreakBlockEvent;
+import com.hypixel.hytale.server.core.inventory.ItemStack;
 import com.hypixel.hytale.server.core.universe.world.World;
 import com.hypixel.hytale.server.core.universe.world.storage.EntityStore;
 import dev.hytalemodding.RitualSpawner;
@@ -27,10 +28,14 @@ public class RitualBreakBlockEvent extends EntityEventSystem<EntityStore, BreakB
                        @NonNullDecl Store<EntityStore> store,
                        @NonNullDecl CommandBuffer<EntityStore> commandBuffer,
                        @NonNullDecl BreakBlockEvent breakBlockEvent) {
-        String itemHolding = breakBlockEvent.getItemInHand().getItemId();
+        ItemStack itemHolding = breakBlockEvent.getItemInHand();
+        String itemId = "Empty";
+        if(itemHolding != null) {
+            itemId = itemHolding.getItemId();
+        }
         Vector3i blockPosition = breakBlockEvent.getTargetBlock();
         World world = store.getExternalData().getWorld();
-        ritualSpawner.blockChangeEvent(itemHolding, blockPosition, world);
+        ritualSpawner.blockChangeEvent(itemId, blockPosition, world);
     }
 
     @NullableDecl

src/main/java/dev/hytalemodding/events/RitualPlaceBlockEvent.java

@@ -6,6 +6,7 @@ import com.hypixel.hytale.component.CommandBuffer;
 import com.hypixel.hytale.component.Store;
 import com.hypixel.hytale.component.query.Query;
 import com.hypixel.hytale.server.core.event.events.ecs.PlaceBlockEvent;
+import com.hypixel.hytale.server.core.inventory.ItemStack;
 import com.hypixel.hytale.server.core.universe.world.World;
 import dev.hytalemodding.RitualSpawner;
 import com.hypixel.hytale.component.system.EntityEventSystem;
@@ -27,10 +28,14 @@ public class RitualPlaceBlockEvent extends EntityEventSystem<EntityStore, PlaceB
                        @NonNullDecl Store<EntityStore> store,
                        @NonNullDecl CommandBuffer<EntityStore> commandBuffer,
                        @NonNullDecl PlaceBlockEvent placeBlockEvent) {
-        String blockId = placeBlockEvent.getItemInHand().getItemId();
+        ItemStack itemHolding = placeBlockEvent.getItemInHand();
+        String itemId = "Empty";
+        if(itemHolding != null) {
+            itemId = itemHolding.getItemId();
+        }
         Vector3i targetPosition = placeBlockEvent.getTargetBlock();
         World world = store.getExternalData().getWorld();
-        ritualSpawner.blockChangeEvent(blockId, targetPosition, world);
+        ritualSpawner.blockChangeEvent(itemId, targetPosition, world);
     }
 
     @NullableDecl