From 1bfd5ed0cdf09f88b24cd4160b46983757bbecc7 Mon Sep 17 00:00:00 2001
From: Jan Schmidt <jan@centricular.com>
Date: Mon, 7 Aug 2023 02:31:50 +1000
Subject: [PATCH] a/math: Add m_vec3_inverse()

Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2188>
---
 src/xrt/auxiliary/math/m_vec3.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/xrt/auxiliary/math/m_vec3.h b/src/xrt/auxiliary/math/m_vec3.h
index df4620dbd..cb3df47f7 100644
--- a/src/xrt/auxiliary/math/m_vec3.h
+++ b/src/xrt/auxiliary/math/m_vec3.h
@@ -67,6 +67,13 @@ m_vec3_div_scalar(struct xrt_vec3 l, float r)
 	return ret;
 }
 
+static inline struct xrt_vec3
+m_vec3_inverse(struct xrt_vec3 v)
+{
+	struct xrt_vec3 ret = {-v.x, -v.y, -v.z};
+	return ret;
+}
+
 static inline float
 m_vec3_dot(struct xrt_vec3 l, struct xrt_vec3 r)
 {