From 1eaf2da087ab028b1b859551605bdf8a32f683e5 Mon Sep 17 00:00:00 2001
From: aozhiwei <aozhiwe@kingsome.cn>
Date: Mon, 18 Mar 2019 17:40:08 +0800
Subject: [PATCH] add LengthSqr

---
 a8/sysutils.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/a8/sysutils.h b/a8/sysutils.h
index 23f98d0..55fe1f6 100644
--- a/a8/sysutils.h
+++ b/a8/sysutils.h
@@ -48,6 +48,12 @@ namespace a8
         return v < hi ? (v > lo ? v : lo) : hi;
     }
 
+    template <typename T>
+    const T& LengthSqr(const T& v)
+    {
+        return v.x * v.x + v.y * v.y;
+    }
+
     template <typename T>
     void SetToVector(std::set<T>& set_v, std::vector<T>& vector_v)
     {