Basic AI defending

core/src/mindustry/game/EventType.java

@@ -249,6 +249,21 @@ public class EventType{
         }
     }
 
+    /**
+     * Called when a bullet damages a building. May not be called for all damage events!
+     * This event is re-used! Never do anything to re-raise this event in the listener.
+     * */
+    public static class BuildDamageEvent{
+        public Building build;
+        public Bullet source;
+
+        public BuildDamageEvent set(Building build, Bullet source){
+            this.build = build;
+            this.source = source;
+            return this;
+        }
+    }
+
     /**
      * Called *before* a tile has changed.
      * WARNING! This event is special: its instance is reused! Do not cache or use with a timer.

core/src/mindustry/game/Rules.java

@@ -237,8 +237,7 @@ public class Rules{
 
         public TeamRule get(Team team){
             TeamRule out = values[team.id];
-            if(out == null) values[team.id] = (out = new TeamRule());
-            return out;
+            return out == null ? (values[team.id] = new TeamRule()) : out;
         }
 
         @Override