1 files changed, 4 insertions(+), 4 deletions(-)

M ahrs/tilt/tilt.ha

@@ 9,14 9,14 @@ export fn new(neutral: (f64, f64, f64)) tilt = {
 };
 
 export fn estimate(tilt: tilt, readings: (f64, f64, f64)) quaternion::quaternion = {
-	// r = q neutral q^(-1), find q
+	// neutral = q r q^(-1), find q
 	let r = quaternion::normalize((0.0, readings.0, readings.1, readings.2));
 	const dot = tilt.neutral.1 * r.1  + tilt.neutral.2 * r.2 + tilt.neutral.3 * r.3;
 	const angle = math::acosf64(dot);
 	const axis = (
-		tilt.neutral.2 * r.3 - tilt.neutral.3 * r.2,
-		tilt.neutral.3 * r.1 - tilt.neutral.1 * r.3,
-		tilt.neutral.1 * r.2 - tilt.neutral.2 * r.1,
+		r.2 * tilt.neutral.3 - r.3 * tilt.neutral.2,
+		r.3 * tilt.neutral.1 - r.1 * tilt.neutral.3,
+		r.1 * tilt.neutral.2 - r.2 * tilt.neutral.1,
 	);
 	return quaternion::from_axis_angle(axis, angle);
 };