1 files changed, 9 insertions, 8 deletions
diff --git a/composeApp/src/commonMain/kotlin/coffee/liz/ecs/System.kt b/composeApp/src/commonMain/kotlin/coffee/liz/ecs/System.kt
index 0f8ef2a..e763c9c 100644
--- a/composeApp/src/commonMain/kotlin/coffee/liz/ecs/System.kt
+++ b/composeApp/src/commonMain/kotlin/coffee/liz/ecs/System.kt
@@ -1,22 +1,23 @@
 package coffee.liz.ecs
 
 import kotlin.reflect.KClass
+import kotlin.time.Duration
 
 /**
- * Systems contain the logic that operates on entities with specific components.
+ * System is a component that updates the world state.
+ * @param Outside is the state of the stuff outside the world (input, etc.).
  */
-interface System {
+interface System<Outside> {
     /**
      * Systems that must run before this system in the update loop.
-     * Used to construct a dependency DAG.
      */
-    val dependencies: Set<KClass<out System>>
+    val dependencies: Set<KClass<out System<*>>>
         get() = emptySet()
 
     /**
-     * Update this system. Called once per frame.
-     * @param world The world containing entities and systems
-     * @param deltaTime Time elapsed since last update in seconds
+     * Integrate this system over [deltaTime].
+     * @param world [World]
+     * @param deltaTime [Duration] since last update
      */
-    fun update(world: World, deltaTime: Float)
+    fun update(world: World<Outside>, state: Outside, deltaTime: Duration)
 }