From f6fbad0e6da336cf5e4108df58634329cfa8e77c Mon Sep 17 00:00:00 2001
From: Matt Low <mattjlow94@gmail.com>
Date: Sat, 28 Dec 2019 12:48:20 +0400
Subject: [PATCH] Shorter turning code using vector math

---
 core/src/com/me/pacman/entity/Entity.java     |  4 ++
 .../com/me/pacman/entity/MovableEntity.java   | 58 +++++--------------
 2 files changed, 19 insertions(+), 43 deletions(-)

diff --git a/core/src/com/me/pacman/entity/Entity.java b/core/src/com/me/pacman/entity/Entity.java
index dc5e774..b5b5525 100644
--- a/core/src/com/me/pacman/entity/Entity.java
+++ b/core/src/com/me/pacman/entity/Entity.java
@@ -30,6 +30,10 @@ public abstract class Entity {
         return (int) pos.x == (int) other.pos.x && (int) pos.y == (int) other.pos.y;
     }
 
+    public Vector2 getTileVector(float offset) {
+        return new Vector2((int) pos.x + offset, (int) pos.y + offset);
+    }
+
     public Vector2 getTileVector() {
         return new Vector2((int) pos.x, (int) pos.y);
     }
diff --git a/core/src/com/me/pacman/entity/MovableEntity.java b/core/src/com/me/pacman/entity/MovableEntity.java
index b7e5c56..0b05472 100644
--- a/core/src/com/me/pacman/entity/MovableEntity.java
+++ b/core/src/com/me/pacman/entity/MovableEntity.java
@@ -43,51 +43,23 @@ public abstract class MovableEntity extends Entity {
 
         if (nextDirection != null) {
             boolean turned = false;
-            switch (nextDirection) {
-                case UP:
-                    nextTile = state.level.getTile(pos.x, pos.y + 1f);
-                    if (nextTile == null) {
-                        if (currDirection == Direction.DOWN) {
-                            turned = true;
-                        }
-                    } else if (nextTile.isPassable() && Math.abs(pos.x - ((int) pos.x + 0.5f)) <= tolerance) {
-                        pos.x = ((int) pos.x) + 0.5f;
+            nextTile = state.level.getTile(nextDirection.getVector().add(pos));
+            if (nextTile == null) {
+                // turned around immediately after existing tunnel (or trying to turn 90 degrees after entering tunnel)
+                if (nextDirection.isOpposite(currDirection)) {
+                    // only allow if turning 180 degrees
+                    turned = true;
+                }
+            } else {
+                if (nextTile.isPassable()) {
+                    // it's possible to turn - are we close enough to our tile's center to make the turn?
+                    Vector2 tileCenter = getTileVector(0.5f);
+                    if (pos.dst2(tileCenter) <= tolerance * tolerance) {
+                        // yes, move us to the center of our tile
+                        pos = tileCenter;
                         turned = true;
                     }
-                    break;
-                case RIGHT:
-                    nextTile = state.level.getTile(pos.x + 1f, pos.y);
-                    if (nextTile == null) {
-                        if (currDirection == Direction.LEFT) {
-                            turned = true;
-                        }
-                    } else if (nextTile.isPassable() && Math.abs(pos.y - ((int) pos.y + 0.5f)) <= tolerance) {
-                        pos.y = ((int) pos.y) + 0.5f;
-                        turned = true;
-                    }
-                    break;
-                case DOWN:
-                    nextTile = state.level.getTile(pos.x, pos.y - 1f);
-                    if (nextTile == null) {
-                        if (currDirection == Direction.UP) {
-                            turned = true;
-                        }
-                    } else if (nextTile.isPassable() && Math.abs(pos.x - ((int) pos.x + 0.5f)) <= tolerance) {
-                        pos.x = ((int) pos.x) + 0.5f;
-                        turned = true;
-                    }
-                    break;
-                case LEFT:
-                    nextTile = state.level.getTile(pos.x - 1f, pos.y);
-                    if (nextTile == null) {
-                        if (currDirection == Direction.RIGHT) {
-                            turned = true;
-                        }
-                    } else if (nextTile.isPassable() && Math.abs(pos.y - ((int) pos.y + 0.5f)) <= tolerance) {
-                        pos.y = ((int) pos.y) + 0.5f;
-                        turned = true;
-                    }
-                    break;
+                }
             }
             if (turned) {
                 currDirection = nextDirection;