From 5f3beb68992828cd4a82fc652a4dc740290d1af7 Mon Sep 17 00:00:00 2001
From: Monster Iestyn <iestynjealous@ntlworld.com>
Date: Sat, 2 Apr 2016 20:09:00 +0100
Subject: [PATCH] Fix M_PI not being defined for Visual Studio

---
 src/doomdef.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/doomdef.h b/src/doomdef.h
index 88575ea7..e6327998 100644
--- a/src/doomdef.h
+++ b/src/doomdef.h
@@ -101,6 +101,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#define _USE_MATH_DEFINES // fixes M_PI errors in r_plane.c for Visual Studio
 #include <math.h>
 
 #ifdef GETTEXT