From 27d4879b1bca3f11cbeb16efae3b295b6a9df9ea Mon Sep 17 00:00:00 2001
From: Unknown <marty.oehme@gmail.com>
Date: Wed, 17 Oct 2018 20:56:30 +0200
Subject: [PATCH] Extract RuleSet Class from Simulation

---
 lib/src/RuleSet.dart    | 27 ++++++++++++++++++++++++++
 lib/src/Simulation.dart | 43 ++++++-----------------------------------
 2 files changed, 33 insertions(+), 37 deletions(-)
 create mode 100644 lib/src/RuleSet.dart

diff --git a/lib/src/RuleSet.dart b/lib/src/RuleSet.dart
new file mode 100644
index 0000000..edfc5a9
--- /dev/null
+++ b/lib/src/RuleSet.dart
@@ -0,0 +1,27 @@
+import 'dart:math';
+
+import 'package:collection/collection.dart';
+
+abstract class RuleSet {
+  int checkRange;
+
+  bool checkSurvival(int neighbors);
+  bool checkBirth(int neighbors);
+}
+
+class Pattern<Point> extends DelegatingList<Point> {
+  final String _name;
+  Pattern(String name, List base)
+      : _name = name,
+        super(base);
+
+  String get name => _name;
+}
+
+class GameOfLife implements RuleSet {
+  int checkRange = 1;
+
+  bool checkSurvival(int neighbors) =>
+      neighbors == 2 || neighbors == 3 ? true : false;
+  bool checkBirth(int neighbors) => neighbors == 3 ? true : false;
+}
diff --git a/lib/src/Simulation.dart b/lib/src/Simulation.dart
index 02c3c3a..05db54b 100644
--- a/lib/src/Simulation.dart
+++ b/lib/src/Simulation.dart
@@ -2,11 +2,13 @@ import 'dart:html' as html;
 import 'dart:math' as math;
 
 import 'package:rules_of_living/src/Grid.dart';
+import 'package:rules_of_living/src/RuleSet.dart';
 
 enum CellPattern { SpaceShip, Blinker }
 
 class Simulation {
   final Grid<bool> map;
+  RuleSet rules = GameOfLife();
 
   bool _dirty = true;
   bool _renderEdges = true;
@@ -28,14 +30,6 @@ class Simulation {
 
   void reset() {
     map.setAll(0, List.filled(map.length, false));
-    if (_startingSeed != null)
-      addPattern(
-          pattern: _pattern,
-          dispersal: _dispersal,
-          amount: _amount,
-          seed: _startingSeed,
-          x: _x,
-          y: _y);
     _dirty = true;
   }
 
@@ -56,31 +50,6 @@ class Simulation {
     int cx = x ?? rng.nextInt(map.width ~/ 3) + (map.width ~/ 3);
     int cy = y ?? rng.nextInt(map.height ~/ 3) + (map.height ~/ 3);
     switch (pattern) {
-      // Two blocks, offset
-      // ##
-      //   ##
-      case CellPattern.Blinker:
-        setCellState(cx, cy, true);
-        setCellState(cx + 1, cy, true);
-        setCellState(cx, cy + 1, true);
-        setCellState(cx + 1, cy + 1, true);
-
-        setCellState(cx + 2, cy + 2, true);
-        setCellState(cx + 3, cy + 2, true);
-        setCellState(cx + 2, cy + 3, true);
-        setCellState(cx + 3, cy + 3, true);
-        break;
-      // A 'gliding' Spaceship
-      //   #
-      //    #
-      //  ###
-      case CellPattern.SpaceShip:
-        setCellState(1 + cx, 0 + cy, true);
-        setCellState(2 + cx, 1 + cy, true);
-        setCellState(2 + cx, 2 + cy, true);
-        setCellState(1 + cx, 2 + cy, true);
-        setCellState(0 + cx, 2 + cy, true);
-        break;
       default:
         int sanityCheck = 0;
         for (var i = 0; i < (_amount); i++) {
@@ -130,17 +99,17 @@ class Simulation {
     for (int i = 0; i < map.length; i++) {
       math.Point p = map.toCoordinates(i);
       bool cell = map[i];
-      int neighbors = getSurroundingNeighbors(p.x, p.y, 1);
-      if (cell == false && neighbors == 3) {
+      int neighbors = getNeighbors(p.x, p.y, 1);
+      if (cell == false && rules.checkBirth(neighbors) == true) {
         stateChanges[i] = true;
-      } else if (cell == true && neighbors != 2 && neighbors != 3) {
+      } else if (cell == true && rules.checkSurvival(neighbors) == false) {
         stateChanges[i] = false;
       }
     }
     return stateChanges;
   }
 
-  int getSurroundingNeighbors(int x, int y, int range) {
+  int getNeighbors(int x, int y, int range) {
     int count = 0;
     for (int ix = -range + x; ix <= range + x; ix++) {
       for (int iy = -range + y; iy <= range + y; iy++) {