Implement FrightBehaviour

This took way too long.

core/src/com/me/pacman/entity/Ghost.java

@@ -8,6 +8,8 @@ import com.me.pacman.entity.ai.Target;
 import com.me.pacman.level.LevelTile;
 import com.me.pacman.state.PlayState;
 
+import java.util.ArrayList;
+
 public class Ghost extends MovableEntity {
 
     public static final Direction[] GHOST_ORDER = { Direction.UP, Direction.LEFT, Direction.DOWN, Direction.RIGHT };
@@ -17,8 +19,8 @@ public class Ghost extends MovableEntity {
     public Behaviour currentBehaviour;
 
     public Behaviour chaseBehaviour;
-    public Behaviour freightBehaviour;
     public Behaviour scatterBehaviour;
+    public Behaviour frightBehaviour;
 
     public TextureRegion[][] sprite;
 
@@ -26,13 +28,13 @@ public class Ghost extends MovableEntity {
     private int counter = 0;
 
     public Ghost(PlayState state, float x, float y, Direction direction, int spriteIndex,
-                 Behaviour chaseBehaviour, Behaviour freightBehaviour, Behaviour scatterBehaviour) {
+                 Behaviour chaseBehaviour, Behaviour scatterBehaviour) {
         super(state, x, y, 7.03f, true, direction, 0.1f);
         this.state = state;
         this.spriteIndex = spriteIndex;
         this.chaseBehaviour = chaseBehaviour;
-        this.freightBehaviour = freightBehaviour;
         this.scatterBehaviour = scatterBehaviour;
+        this.frightBehaviour = new FrightenedBehaviour(state);
         sprite = state.getGame().assets.ghosts;
     }
 
@@ -53,7 +55,7 @@ public class Ghost extends MovableEntity {
     public void update(float dt) {
         super.update(dt);
 
-        if (!state.paused && age % 20 == 0) {
+        if (age % 20 == 0) {
             counter++;
         }
 
@@ -66,16 +68,19 @@ public class Ghost extends MovableEntity {
         }
 
         Target target = currentBehaviour.getTarget();
-        Vector2 ahead = new Vector2((int) pos.x, (int) pos.y).add(currDirection.getVector());
+        if (target == null) {
+            // no target, carry on current course
+            return;
+        }
 
-        Direction bestDirection = null;
+        Vector2 ahead = new Vector2((int) pos.x, (int) pos.y).add(currDirection.getVector());
         float shortest = Float.MAX_VALUE;
+        Direction nextDirection = null;
 
         for (Direction dir : GHOST_ORDER) {
             if (dir.isOpposite(currDirection)) {
                 continue;
             }
-
             Vector2 adjacent = dir.getVector().add(ahead);
             LevelTile nextTile = state.level.getTile(adjacent);
             if (nextTile != null && nextTile.isPassable()) {
@@ -83,14 +88,12 @@ public class Ghost extends MovableEntity {
                 float d = target.distance_sqr(adjacent);
                 if (d < shortest) {
                     shortest = d;
-                    bestDirection = dir;
+                    nextDirection = dir;
                 }
             }
         }
 
-        if (bestDirection != null) {
+        setNextDirection(nextDirection);
-            setNextDirection(bestDirection);
-        }
     }
 
     private class ReturnToBase extends Behaviour {
@@ -108,4 +111,56 @@ public class Ghost extends MovableEntity {
 
     }
 
+    private class FrightenedBehaviour extends Behaviour {
+
+        private Target target;
+
+        public FrightenedBehaviour(PlayState state) {
+            super(state);
+        }
+
+        @Override
+        public Target getTarget() {
+            if (target != null && !target.targetReached(pos)) {
+                return target;
+            }
+
+            ArrayList<Vector2> adjacentTiles = new ArrayList<>(3);
+            ArrayList<Direction> possibleTurns = new ArrayList<>(3);
+            Vector2 ahead = new Vector2((int) pos.x, (int) pos.y).add(currDirection.getVector());
+
+            for (Direction dir : GHOST_ORDER) {
+                if (dir.isOpposite(currDirection)) {
+                    // Don't consider going backwards
+                    continue;
+                }
+                Vector2 adjacent = dir.getVector().add(ahead);
+                LevelTile nextTile = state.level.getTile(adjacent);
+                if (nextTile != null && nextTile.isPassable()) {
+                    adjacentTiles.add(adjacent);
+                    possibleTurns.add(dir);
+                }
+            }
+
+            if (possibleTurns.size() == 0) {
+                // No possible turns means no valid tiles ahead, which would be the tunnel.
+                target = null;
+            } else if (possibleTurns.size() == 1) {
+                if (possibleTurns.get(0) == currDirection) {
+                    // can only go straight, so no target
+                    target = null;
+                } else {
+                    // turn the only possible direction
+                    target = new Target(adjacentTiles.get(0));
+                }
+            } else {
+                // n-way intersection, pick random direction
+                int rand = state.random.nextInt(adjacentTiles.size());
+                target = new Target(adjacentTiles.get(rand));
+            }
+            return target;
+        }
+
+    }
+
 }

core/src/com/me/pacman/entity/Pacman.java

@@ -46,11 +46,11 @@ public class Pacman extends MovableEntity {
 
         super.update(dt);
 
-        if (!state.paused && canMove && age % 4 == 0) {
+        if (canMove && age % 4 == 0) {
             counter += 1;
         }
 
-        if (age % 8 == 0 && !alive) {
+        if (!alive && age % 8 == 0) {
             deathFrame++;
         }
 

core/src/com/me/pacman/entity/ai/Target.java

@@ -32,4 +32,8 @@ public class Target {
         return this.x == (int) x && this.y == (int) y;
     }
 
+    public boolean targetReached(Vector2 vec) {
+        return targetReached(vec.x, vec.y);
+    }
+
 }

core/src/com/me/pacman/state/PlayState.java

@@ -15,17 +15,21 @@ import com.me.pacman.entity.ai.BlinkyChaseBehaviour;
 import com.me.pacman.level.Level;
 import com.me.pacman.level.LevelTile;
 
+import java.util.Random;
+
 public class PlayState extends LevelState {
 
     private Texture levelBackground;
     private BitmapFont font;
 
+    private TextureRegion lifeSprite;
+
     private int pelletCount;
     private int pelletEatenCount;
     private int score;
     private int lives;
     private int round;
-    public boolean paused = false;
+    private boolean paused = false;
 
     private long sirenId;
 
@@ -36,7 +40,7 @@ public class PlayState extends LevelState {
 
     private boolean pacmanCaught;
 
-    private TextureRegion lifeSprite;
+    public Random random;
 
     public Pacman pacman;
     public Ghost[] ghosts;
@@ -90,7 +94,6 @@ public class PlayState extends LevelState {
         if (paused) {
             game.assets.getFont().setColor(Color.YELLOW);
             game.assets.getFont().draw(game.batch, "paused", 90, 151);
-            return;
         }
     }
 
@@ -127,6 +130,8 @@ public class PlayState extends LevelState {
             }
         }
 
+        dt = 1/60f;
+
         if (!pacmanCaught) {
             for (Ghost ghost : ghosts) {
                 if (ghost == null) {
@@ -184,7 +189,7 @@ public class PlayState extends LevelState {
         level = new Level(game,"level");
 
         pacman = new Pacman(this, false);
-        ghosts[0] = new Ghost(this, 14, 19.5f, Direction.LEFT, 0, new BlinkyChaseBehaviour(this), null, null);
+        ghosts[0] = new Ghost(this, 14, 19.5f, Direction.LEFT, 0, new BlinkyChaseBehaviour(this), null);
         ghosts[0].currentBehaviour = ghosts[0].chaseBehaviour;
 
         game.assets.siren.stop(sirenId);
@@ -205,8 +210,10 @@ public class PlayState extends LevelState {
         lives--;
         pacmanCaught = false;
 
+        random = new Random(897198256012865L);
+
         pacman = new Pacman(this, false);
-        ghosts[0] = new Ghost(this, 14, 19.5f, Direction.LEFT, 0, new BlinkyChaseBehaviour(this), null, null);
+        ghosts[0] = new Ghost(this, 14, 19.5f, Direction.LEFT, 0, new BlinkyChaseBehaviour(this), null);
         ghosts[0].currentBehaviour = ghosts[0].chaseBehaviour;
     }