From 028466e823b5f78b28d348cd6d992f5b836ffe83 Mon Sep 17 00:00:00 2001
From: Roman <romsa9@gmail.com>
Date: Wed, 8 Apr 2015 22:47:14 -0400
Subject: [PATCH] New diagonal movement option: only when obstacles present.

---
 src/core/DiagonalMovement.js | 3 ++-
 src/core/Grid.js             | 5 +++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/core/DiagonalMovement.js b/src/core/DiagonalMovement.js
index 3cb3734c..5e9878cd 100644
--- a/src/core/DiagonalMovement.js
+++ b/src/core/DiagonalMovement.js
@@ -2,7 +2,8 @@ var DiagonalMovement = {
     Always: 1,
     Never: 2,
     IfAtMostOneObstacle: 3,
-    OnlyWhenNoObstacles: 4
+    OnlyWhenNoObstacles: 4,
+    OnlyWhenObstacles: 5,
 };
 
 module.exports = DiagonalMovement;
\ No newline at end of file
diff --git a/src/core/Grid.js b/src/core/Grid.js
index 31ae6ee3..5d1d08f1 100644
--- a/src/core/Grid.js
+++ b/src/core/Grid.js
@@ -192,6 +192,11 @@ Grid.prototype.getNeighbors = function(node, diagonalMovement) {
         d1 = true;
         d2 = true;
         d3 = true;
+    } else if (diagonalMovement === DiagonalMovement.OnlyWhenObstacles) {
+        d0 = !(s3 || s0);
+        d1 = !(s0 || s1);
+        d2 = !(s1 || s2);
+        d3 = !(s2 || s3);
     } else {
         throw new Error('Incorrect value of diagonalMovement');
     }