.

src/arenas/tron/Direction.php

@@ -6,4 +6,37 @@ class Direction
   private static $left = 2;
   private static $right = 3;
   
+  private $value;
+  
+  public function __construct(){
+    $this->value = 0;
+  }
+  public function __toString(){
+    switch ($this->value){
+      case Direction::$top:
+	return "y+";
+	break;
+      case Direction::$bottom:
+	return "y-";
+	break;
+      case Direction::$left:
+	return "x-";
+	break;
+      case Direction::$right:
+	return "x+";
+	break; 
+    }
+  }
+  public function opposite(){
+     $opposites = array(
+	Direction::$top => Direction::$bottom,
+	Direction::$bottom => Direction::$top,
+	Direction::$left => Direction::$right,
+	Direction::$right => Direction::$left
+     );
+     
+    $opposite = new Direction();
+    $opposite->value = $opposites[$this->value];
+  
+  }
 }