From 245e91bca168d12cd6d26f5c30da97785486608d Mon Sep 17 00:00:00 2001
From: Luca Toniolo <10792599+grandixximo@users.noreply.github.com>
Date: Sun, 3 May 2026 08:43:01 +0800
Subject: [PATCH] state-tags: replace M_PI_2 with M_PI/2 for RTAI build

M_PI_2 is a glibc extension and is not exposed by RTAI's rtapi_math.h,
so the RTAI build fails with 'M_PI_2 undeclared' at control.c:2283.
M_PI is available in both, so use M_PI/2.0 instead.
---
 src/emc/motion/control.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/emc/motion/control.c b/src/emc/motion/control.c
index 5b0a592b990..bf88b09ef08 100644
--- a/src/emc/motion/control.c
+++ b/src/emc/motion/control.c
@@ -2280,11 +2280,11 @@ static void update_status(void)
 
 			// G3 (CCW): Heading is Radial Angle + 90 degrees
 			if (motion_type == 30) {
-				heading_deg = (angle_rad + M_PI_2) * (180.0 / M_PI);
-			} 
+				heading_deg = (angle_rad + (M_PI / 2.0)) * (180.0 / M_PI);
+			}
 			// G2 (CW): Heading is Radial Angle - 90 degrees
 			else {
-				heading_deg = (angle_rad - M_PI_2) * (180.0 / M_PI);
+				heading_deg = (angle_rad - (M_PI / 2.0)) * (180.0 / M_PI);
 			}
 			// 0-360 Normalization
 			while (heading_deg < 0) heading_deg += 360.0;