feat: damage multiBlock Structures

module.txt

@@ -59,6 +59,10 @@
             "id": "Pathfinding",
             "minVersion": "1.0.0"
         },
+        {
+            "id": "MultiBlock",
+            "minVersion": "1.1.0"
+        },
         {
             "id": "Tasks",
             "minVersion": "1.0.0"

src/main/java/org/terasology/ligthandshadow/componentsystem/controllers/MultiBlockSystem.java

@@ -0,0 +1,66 @@
+// Copyright 2021 The Terasology Foundation
+// SPDX-License-Identifier: Apache-2.0
+package org.terasology.ligthandshadow.componentsystem.controllers;
+
+import java.util.Collection;
+
+import org.joml.Vector3i;
+import org.terasology.engine.entitySystem.entity.EntityRef;
+import org.terasology.engine.entitySystem.event.EventPriority;
+import org.terasology.engine.entitySystem.event.ReceiveEvent;
+import org.terasology.engine.entitySystem.prefab.Prefab;
+import org.terasology.engine.entitySystem.systems.BaseComponentSystem;
+import org.terasology.engine.entitySystem.systems.RegisterMode;
+import org.terasology.engine.entitySystem.systems.RegisterSystem;
+import org.terasology.engine.logic.characters.events.AttackEvent;
+import org.terasology.engine.logic.health.EngineDamageTypes;
+import org.terasology.engine.logic.inventory.ItemComponent;
+import org.terasology.engine.world.BlockEntityRegistry;
+import org.terasology.module.health.events.DoDamageEvent;
+import org.terasology.engine.registry.In;
+import org.terasology.multiBlock2.component.MultiBlockMainComponent;
+import org.terasology.multiBlock2.component.MultiBlockMemberComponent;
+
+/**
+ * Damages all the blocks in a multiBlock Structure when any block in the structure is damaged.
+ */
+@RegisterSystem(RegisterMode.AUTHORITY)
+public class MultiBlockSystem extends BaseComponentSystem {
+    @In
+    private BlockEntityRegistry blockEntityRegistry;
+
+    @ReceiveEvent(priority = EventPriority.PRIORITY_CRITICAL)
+    public void onDamageDone(AttackEvent event, EntityRef entity) {
+        int damage = 1;
+        Prefab damageType = EngineDamageTypes.PHYSICAL.get();
+        ItemComponent item = event.getDirectCause().getComponent(ItemComponent.class);
+        if (item != null) {
+            damage = item.baseDamage;
+            if (item.damageType != null) {
+                damageType = item.damageType;
+            }
+        }
+        Collection<Vector3i> blocks = getBlocks(entity);
+        if (blocks != null) {
+            for (Vector3i pos : blocks) {
+                EntityRef block = blockEntityRegistry.getBlockEntityAt(pos);
+                block.send(new DoDamageEvent(damage, damageType, event.getInstigator(), event.getDirectCause()));
+                event.consume();
+            }
+        }
+    }
+
+    public Collection<Vector3i> getBlocks(EntityRef entity) {
+        Collection<Vector3i> blocks = null;
+        EntityRef mainBlock = null;
+        if (entity.hasComponent(MultiBlockMainComponent.class)) {
+            mainBlock = entity;
+        } else if (entity.hasComponent(MultiBlockMemberComponent.class)) {
+            mainBlock = blockEntityRegistry.getBlockEntityAt(entity.getComponent(MultiBlockMemberComponent.class).getMainBlockLocation());
+        }
+        if (mainBlock != null) {
+            blocks = mainBlock.getComponent(MultiBlockMainComponent.class).getMultiBlockMembers();
+        }
+        return blocks;
+    }
+}