Support for unit missiles

core/src/mindustry/entities/comp/TimedKillComp.java

@@ -0,0 +1,28 @@
+package mindustry.entities.comp;
+
+import arc.math.*;
+import arc.util.*;
+import mindustry.annotations.Annotations.*;
+import mindustry.gen.*;
+
+//basically just TimedComp but kills instead of removing.
+@Component
+abstract class TimedKillComp implements Entityc, Healthc, Scaled{
+    float time, lifetime;
+
+    //called last so pooling and removal happens then.
+    @MethodPriority(100)
+    @Override
+    public void update(){
+        time = Math.min(time + Time.delta, lifetime);
+
+        if(time >= lifetime){
+            kill();
+        }
+    }
+
+    @Override
+    public float fin(){
+        return time / lifetime;
+    }
+}