From 915dad2da4854d794be67f7ba2d6a625fcb5c042 Mon Sep 17 00:00:00 2001
From: Randy Mackay <rmackay9@yahoo.com>
Date: Fri, 6 Jun 2014 17:56:35 +0900
Subject: [PATCH] AC_Circle: use fast_atan2 to calc bearing from center

This does not save much time because it's only called at initialisation
---
 libraries/AC_WPNav/AC_Circle.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/AC_WPNav/AC_Circle.cpp b/libraries/AC_WPNav/AC_Circle.cpp
index 9cd4d11614..48bb5ef83e 100644
--- a/libraries/AC_WPNav/AC_Circle.cpp
+++ b/libraries/AC_WPNav/AC_Circle.cpp
@@ -248,7 +248,7 @@ void AC_Circle::init_start_angle(bool use_heading)
             _angle = wrap_PI(_ahrs.yaw-PI);
         } else {
             // get bearing from circle center to vehicle in radians
-            float bearing_rad = ToRad(90) + atan2f(-(curr_pos.x-_center.x), curr_pos.y-_center.y);
+            float bearing_rad = ToRad(90) + fast_atan2(-(curr_pos.x-_center.x), curr_pos.y-_center.y);
             _angle = wrap_PI(bearing_rad);
         }
     }