improve static tree construction

include/bounce/collision/trees/static_tree.h

@@ -77,6 +77,9 @@ private :
 		}
 	};
 
+	// 
+	void Build(const b3AABB3* set, b3Node* node, u32* indices, u32 numObjects, u32 minObjectsPerLeaf, u32 nodeCapacity, u32& leafCount, u32& internalCount);
+
 	// The nodes of this tree stored in an array.
 	u32 m_nodeCount;
 	b3Node* m_nodes;