From 2d2365e606c530bd113cb04b83465a5c0b9a537e Mon Sep 17 00:00:00 2001
From: Marty Oehme <marty.oehme@gmail.com>
Date: Sat, 7 Jul 2018 21:42:07 +0200
Subject: [PATCH] Fix Simulation Reset not Replicating the Starting Pattern

Now keeps the original parameters for the first pattern of a grid stored and can replicate them reliably.
---
 lib/src/Grid.dart | 35 +++++++++++++++++++++++++++++------
 1 file changed, 29 insertions(+), 6 deletions(-)

diff --git a/lib/src/Grid.dart b/lib/src/Grid.dart
index c03b413..c35bd16 100644
--- a/lib/src/Grid.dart
+++ b/lib/src/Grid.dart
@@ -12,6 +12,12 @@ class Grid {
   final List<List<Cell>> map;
 
   bool _dirty = true;
+  int _startingSeed;
+  int _x;
+  int _y;
+  int _amount;
+  int _dispersal;
+  Pattern _pattern;
 
   Grid(int w, int h)
       : this.w = w,
@@ -22,9 +28,21 @@ class Grid {
     print("Grid creation finished");
   }
 
-  void startingPattern(
-      {Pattern pattern, int x, int y, int amount, int dispersal}) {
-    math.Random rng = new math.Random();
+  void reset() {
+    map.setAll(0, _buildGrid(w, h));
+    if(_startingSeed != null) addPattern(pattern: _pattern, dispersal: _dispersal,amount: _amount,seed: _startingSeed, x: _x, y: _y);
+    _dirty = true;
+  }
+
+  void addPattern(
+      {Pattern pattern, int x, int y, int amount, int dispersal, int seed}) {
+    _startingSeed = seed ?? DateTime.now().millisecondsSinceEpoch;
+    math.Random rng = new math.Random(_startingSeed);
+    _x = x;
+    _y = y;
+    _amount = amount ?? rng.nextInt(20);
+    _dispersal = dispersal ?? 10;
+    _pattern = pattern;
     int cx = x ?? rng.nextInt(w ~/ 3) + (w ~/ 3);
     int cy = y ?? rng.nextInt(h ~/ 3) + (h ~/ 3);
     switch (pattern) {
@@ -54,9 +72,14 @@ class Grid {
         setCellState(0 + cx, 2 + cy, true);
         break;
       default:
-        for (var i = 0; i < amount ?? rng.nextInt(20); i++) {
-          setCellState(cx + dispersal ?? rng.nextInt(10),
-              cy + dispersal ?? rng.nextInt(10), true);
+        int sanityCheck = 0;
+        for (var i = 0; i < (_amount); i++) {
+          sanityCheck++;
+          getCellState(cx, cy)
+              ? i--
+              : setCellState(cx + rng.nextInt(_dispersal),
+                  cy + rng.nextInt(_dispersal), true);
+          if (sanityCheck > 100 && sanityCheck > i*3) break;
         }
         break;
     }