From a2b9b2264e70cf8b343ed4c26a99759ba8f7758c Mon Sep 17 00:00:00 2001
From: Urban Modig <urban@Urbans-MacBook-Pro.local>
Date: Sun, 17 Aug 2025 20:49:44 +0200
Subject: [PATCH] Improved ghost-move - now ghoest doesnt get stuck

---
 .../game/collision/GhostCollisionChecker.java |  4 +-
 .../java/se/urmo/game/entities/Ghost.java     | 51 ++++++++++---------
 2 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/src/main/java/se/urmo/game/collision/GhostCollisionChecker.java b/src/main/java/se/urmo/game/collision/GhostCollisionChecker.java
index 91489a2..18885e9 100644
--- a/src/main/java/se/urmo/game/collision/GhostCollisionChecker.java
+++ b/src/main/java/se/urmo/game/collision/GhostCollisionChecker.java
@@ -5,7 +5,6 @@ import se.urmo.game.map.GameMap;
 import se.urmo.game.util.Direction;
 
 import java.awt.Point;
-import java.util.Collections;
 import java.util.List;
 
 @Slf4j
@@ -23,7 +22,8 @@ public class GhostCollisionChecker {
     }
 
     public Point canMoveTo(Direction dir, Point pos) {
-        Point pp = new Point(pos.x + dir.dx * GameMap.MAP_TILESIZE/2, pos.y + dir.dy * GameMap.MAP_TILESIZE/2);
+        // -1 is because else we endup in next tile
+        Point pp = new Point(pos.x + dir.dx * (GameMap.MAP_TILESIZE/2 - 1), pos.y + dir.dy * (GameMap.MAP_TILESIZE/2 -1) );
 
         return  ! map.isSolid(pp.x, pp.y) ? pos : null;
     }
diff --git a/src/main/java/se/urmo/game/entities/Ghost.java b/src/main/java/se/urmo/game/entities/Ghost.java
index 5deb5e0..06b0acf 100644
--- a/src/main/java/se/urmo/game/entities/Ghost.java
+++ b/src/main/java/se/urmo/game/entities/Ghost.java
@@ -13,6 +13,7 @@ import java.awt.Graphics;
 import java.awt.Point;
 import java.awt.image.BufferedImage;
 import java.util.List;
+import java.util.stream.Collectors;
 
 @Slf4j
 public class Ghost {
@@ -35,6 +36,8 @@ public class Ghost {
     private int aniIndex = 0;
     private BufferedImage[] animation;
     private int movementTick = 0;
+    private Direction direction;
+    private Direction prevDirection;
 
 
     public Ghost(Game game, GhostCollisionChecker collisionChecker, GhostStrategy strategy) {
@@ -79,26 +82,25 @@ public class Ghost {
     }
 
     private void updatePosition(PacMan pacman) {
-        if(movementTick >= GHOST_MOVEMENT_UPDATE_FREQUENCY) {
-            if(!isAlligned(position)){
-                position = align(position);
-                log.debug("Aligned: {}", position);
-                return;
+        if (movementTick >= GHOST_MOVEMENT_UPDATE_FREQUENCY) {
+            if (isAlligned(position)) {
+                log.info("Evaluating possible directions");
+                prevDirection = direction;
+                direction = chooseDirection(
+                        collisionChecker.calculateDirectionAlternatives(position),
+                        strategy.chooseTarget(pacman, null, null),
+                        prevDirection);
+                log.info("selecting direction {}", direction);
             }
 
-            log.info("Evaluating possible directions");
-            Direction intendedDirection = chooseDirection(
-                    collisionChecker.calculateDirectionAlternatives(position),
-                    strategy.chooseTarget(pacman, null, null));
-
-
-            log.info("selecting direction {}", intendedDirection);
             Point newPosition = new Point(
-                   position.x + intendedDirection.dx * GHOST_SPEED,
-                    position.y + intendedDirection.dy * GHOST_SPEED);
+                    position.x + direction.dx * GHOST_SPEED,
+                    position.y + direction.dy * GHOST_SPEED);
+            log.debug("Next position {}", newPosition);
 
-            Point destination = collisionChecker.canMoveTo(intendedDirection, newPosition);
-            if(destination != null) {
+            Point destination = collisionChecker.canMoveTo(direction, newPosition);
+
+            if (destination != null) {
                 position = destination;
             }
             movementTick = 0;
@@ -108,19 +110,18 @@ public class Ghost {
     private boolean isAlligned(Point pos) {
         int row = pos.x % GameMap.MAP_TILESIZE;
         int col = pos.y % GameMap.MAP_TILESIZE;
-        return row == GameMap.MAP_TILESIZE/2 || col == GameMap.MAP_TILESIZE /2;
-    }
-    private Point align(Point point){
-        int row = point.x / GameMap.MAP_TILESIZE;
-        int col = point.y / GameMap.MAP_TILESIZE;
-        return new Point(row * GameMap.MAP_TILESIZE + GameMap.MAP_TILESIZE /2, col * GameMap.MAP_TILESIZE  + GameMap.MAP_TILESIZE /2);
+        return row == GameMap.MAP_TILESIZE / 2 && col == GameMap.MAP_TILESIZE / 2;
     }
 
-    private Direction chooseDirection(List<Direction> options, Point target) {
-        Direction best = options.getFirst();
+    private Direction chooseDirection(List<Direction> options, Point target, Direction prevDirection) {
+        List<Direction> l = options.stream()
+                // remove any option to go back
+                .filter(d -> !(prevDirection != null && d.equals(prevDirection.opposite())))
+                .toList();
+        Direction best = l.getFirst();
         double bestDist = Double.MAX_VALUE;
 
-        for (Direction d : options) {
+        for (Direction d : l) {
             int nx = position.x + d.dx * GameMap.MAP_TILESIZE;
             int ny = position.y + d.dy * GameMap.MAP_TILESIZE;
             double dist = target.distance(nx, ny);