Core/Collision: Ported dynamic line of sight patch by Silverice from MaNGOS and

added lots of improvements
Please re-extract vmaps

src/server/collision/BoundingIntervalHierarchy.h

@@ -81,13 +81,25 @@ struct AABound
 
 class BIH
 {
-    public:
-        BIH() {};
-        template< class T, class BoundsFunc >
-        void build(const std::vector<T> &primitives, BoundsFunc &getBounds, uint32 leafSize = 3, bool printStats=false)
+    private:
+        void init_empty()
         {
-            if (primitives.empty())
+            tree.clear();
+            objects.clear();
+            // create space for the first node
+            tree.push_back(3 << 30); // dummy leaf
+            tree.insert(tree.end(), 2, 0);
+        }
+    public:
+        BIH() { init_empty(); }
+        template< class BoundsFunc, class PrimArray >
+        void build(const PrimArray &primitives, BoundsFunc &getBounds, uint32 leafSize = 3, bool printStats=false)
+        {
+            if (primitives.size() == 0)
+            {
+                init_empty();
                 return;
+            }
 
             buildData dat;
             dat.maxPrims = leafSize;
@@ -397,4 +409,4 @@ class BIH
         void subdivide(int left, int right, std::vector<uint32> &tempTree, buildData &dat, AABound &gridBox, AABound &nodeBox, int nodeIndex, int depth, BuildStats &stats);
 };
 
-#endif // _BIH_H
+#endif // _BIH_H