From c50e92fb19705ebc4a3fe49df5150c6dd71fcbb3 Mon Sep 17 00:00:00 2001
From: Unknown <marty.oehme@gmail.com>
Date: Tue, 2 Oct 2018 14:55:39 +0200
Subject: [PATCH] Add simple stateChanges map into Simulation

---
 lib/src/Engine.dart     |  3 ++-
 lib/src/Simulation.dart | 16 +++++++---------
 2 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/lib/src/Engine.dart b/lib/src/Engine.dart
index 84d52e8..9855d14 100644
--- a/lib/src/Engine.dart
+++ b/lib/src/Engine.dart
@@ -101,7 +101,8 @@ class Engine {
   /// directly, since it is automatically taken care of by the processing function.
   /// If simulation should be advanced manually one time, prefer using step().
   void update() {
-    if (!_grid.update()) running = false;
+    // TODO: create hasUpdated/hasAdvanced method in simulation to abstract actual updating away
+    if (_grid.update().length != 0) running = false;
   }
 
   /// Advances Logic One Update
diff --git a/lib/src/Simulation.dart b/lib/src/Simulation.dart
index ca7bb71..e451bf0 100644
--- a/lib/src/Simulation.dart
+++ b/lib/src/Simulation.dart
@@ -125,19 +125,17 @@ class Simulation {
     return null;
   }
 
-  bool update() {
-    bool stateChanges = false;
+  Map<int, Cell> update() {
+    Map<int, Cell> stateChanges = Map();
 
     for (int i = 0; i < map.length; i++) {
       math.Point p = map.toCoordinates(i);
-      map[i].update(getSurroundingNeighbors(p.x, p.y, 1));
+      Cell el = map[i];
+      el.update(getSurroundingNeighbors(p.x, p.y, 1));
+      stateChanges[i] = el;
     }
-    // TODO when implementing changeSet we can remove this second loop and add to changeSet in the first
-    map.forEach((Cell el) {
-      if (el.state != el.nextState) stateChanges = true;
-      el.advanceState();
-    });
-    stateChanges ? _dirty = true : false;
+    stateChanges.forEach((_, el) => el.advanceState());
+    stateChanges.length != 0 ? _dirty = true : false;
     return stateChanges;
   }