From 7825035984194b2e723f3c40a2251d23853464e3 Mon Sep 17 00:00:00 2001
From: xdavidwu <xdavidwuph@gmail.com>
Date: Fri, 20 May 2022 00:27:33 +0800
Subject: [PATCH] math::quaternion: add from_euler

---
 math/quaternion/conversion.ha | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/math/quaternion/conversion.ha b/math/quaternion/conversion.ha
index dc493d8..61292d2 100644
--- a/math/quaternion/conversion.ha
+++ b/math/quaternion/conversion.ha
@@ -15,3 +15,18 @@ export fn to_euler(q: quaternion) (f64, f64, f64) = {
 		math::atanf64(2.0 * (q.0 * q.3 + q.1 * q.2) / (1.0 - 2.0 * (q.2 * q.2 + q.3 * q.3))),
 	);
 };
+
+export fn from_euler(v: (f64, f64, f64)) quaternion = {
+	const s0 = math::sinf64(v.0 / 2.0);
+	const c0 = math::cosf64(v.0 / 2.0);
+	const s1 = math::sinf64(v.1 / 2.0);
+	const c1 = math::cosf64(v.1 / 2.0);
+	const s2 = math::sinf64(v.2 / 2.0);
+	const c2 = math::cosf64(v.2 / 2.0);
+	return (
+		c0 * c1 * c2 + s0 * s1 * s2,
+		s0 * c1 * c2 - c0 * s1 * s2,
+		c0 * s1 * c2 + s0 * c1 * s2,
+		c0 * c1 * s2 - s0 * s1 * c2,
+	);
+};
-- 
2.45.2