From 10627af7a85b50bce965245a472d9b69e928d0ba Mon Sep 17 00:00:00 2001
From: Pacien TRAN-GIRARD
Date: Sat, 21 Nov 2015 22:53:24 +0100
Subject: Generalize turn back avoidance to all ProbabilisticAnimals

---
 src/ch/epfl/maze/physical/ProbabilisticAnimal.java | 38 ++++++++++++++++++---
 src/ch/epfl/maze/physical/zoo/Mouse.java           | 39 +---------------------
 2 files changed, 35 insertions(+), 42 deletions(-)

(limited to 'src/ch/epfl/maze')

diff --git a/src/ch/epfl/maze/physical/ProbabilisticAnimal.java b/src/ch/epfl/maze/physical/ProbabilisticAnimal.java
index f62fea1..c4d4f2a 100644
--- a/src/ch/epfl/maze/physical/ProbabilisticAnimal.java
+++ b/src/ch/epfl/maze/physical/ProbabilisticAnimal.java
@@ -3,37 +3,67 @@ package ch.epfl.maze.physical;
 import ch.epfl.maze.util.Direction;
 import ch.epfl.maze.util.Vector2D;
 
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Random;
+import java.util.stream.Collectors;
 
 /**
  * A probabilistic animal that use a random component in its decision making process.
  *
  * @author Pacien TRAN-GIRARD
  */
-
 abstract public class ProbabilisticAnimal extends Animal {
 
     private final Random randomSource;
+    private Direction currentDirection;
 
     /**
      * Constructs a probabilistic animal with a starting position
      *
      * @param position Starting position of the probabilistic animal in the labyrinth
      */
-
     public ProbabilisticAnimal(Vector2D position) {
         super(position); // no pun intended
         this.randomSource = new Random();
+        this.currentDirection = Direction.NONE;
+    }
+
+    /**
+     * Excludes the origin direction for choices.
+     *
+     * @param choices An array of choices
+     * @return An array of smart choices
+     */
+    protected Direction[] excludeOrigin(Direction[] choices) {
+        return (new ArrayList<>(Arrays.asList(choices)))
+                .stream()
+                .filter(dir -> !dir.isOpposite(this.currentDirection))
+                .collect(Collectors.toList())
+                .toArray(new Direction[0]);
     }
 
     /**
-     * Moves according to a <i>random walk</i>.
+     * Returns a random Direction from the given choices.
+     *
+     * @param choices An array of Direction
+     * @return A random Direction taken from the given choices
      */
+    protected Direction getRandomDirection(Direction[] choices) {
+        return choices[randomSource.nextInt(choices.length)];
+    }
 
+    /**
+     * Moves according to an improved version of a <i>random walk</i> : the
+     * probabilistic animal does not directly retrace its steps if not forced.
+     */
     @Override
     public Direction move(Direction[] choices) {
         if (choices.length == 0) return Direction.NONE;
-        return choices[randomSource.nextInt(choices.length)];
+
+        Direction[] smartChoices = choices.length > 1 ? this.excludeOrigin(choices) : choices;
+        this.currentDirection = this.getRandomDirection(smartChoices);
+        return this.currentDirection;
     }
 
 }
diff --git a/src/ch/epfl/maze/physical/zoo/Mouse.java b/src/ch/epfl/maze/physical/zoo/Mouse.java
index b5483c1..08d7f3d 100644
--- a/src/ch/epfl/maze/physical/zoo/Mouse.java
+++ b/src/ch/epfl/maze/physical/zoo/Mouse.java
@@ -2,64 +2,27 @@ package ch.epfl.maze.physical.zoo;
 
 import ch.epfl.maze.physical.Animal;
 import ch.epfl.maze.physical.ProbabilisticAnimal;
-import ch.epfl.maze.util.Direction;
 import ch.epfl.maze.util.Vector2D;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.stream.Collectors;
-
 /**
  * Mouse A.I. that remembers only the previous choice it has made.
  *
  * @author Pacien TRAN-GIRARD
  */
-
 public class Mouse extends ProbabilisticAnimal {
 
-    private Direction previousChoice;
-
     /**
      * Constructs a mouse with a starting position.
      *
      * @param position Starting position of the mouse in the labyrinth
      */
-
     public Mouse(Vector2D position) {
         super(position);
-        this.previousChoice = Direction.NONE;
-    }
-
-    /**
-     * Excludes the origin direction for choices.
-     *
-     * @param choices An array of choices
-     * @return An array of smart choices
-     */
-
-    private Direction[] excludeOrigin(Direction[] choices) {
-        return (new ArrayList<>(Arrays.asList(choices)))
-                .stream()
-                .filter(dir -> !dir.isOpposite(this.previousChoice))
-                .collect(Collectors.toList())
-                .toArray(new Direction[0]);
-    }
-
-    /**
-     * Moves according to an improved version of a <i>random walk</i> : the
-     * mouse does not directly retrace its steps.
-     */
-
-    @Override
-    public Direction move(Direction[] choices) {
-        Direction[] smartChoices = choices.length > 1 ? this.excludeOrigin(choices) : choices;
-        Direction dir = super.move(smartChoices);
-        this.previousChoice = dir;
-        return dir;
     }
 
     @Override
     public Animal copy() {
         return new Mouse(this.getPosition());
     }
+
 }
-- 
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