From 0bc844d6c53f2baf49988020843f6768d2351208 Mon Sep 17 00:00:00 2001
From: Rune Harlyk <rune@harlyk.dk>
Date: Tue, 25 Jun 2024 21:18:23 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=AA=B0=20Adds=20orientation=20store?=
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---
 app/src/lib/stores/orientation.ts | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 app/src/lib/stores/orientation.ts

diff --git a/app/src/lib/stores/orientation.ts b/app/src/lib/stores/orientation.ts
new file mode 100644
index 0000000..d3814eb
--- /dev/null
+++ b/app/src/lib/stores/orientation.ts
@@ -0,0 +1,27 @@
+import { readable } from 'svelte/store';
+
+export const heading = readable(0, (set) => {
+	const updateHeading = (e: any) => {
+		let alpha;
+		if (e.webkitCompassHeading) alpha = e.webkitCompassHeading;
+		else if (e.alpha) alpha = e.alpha;
+		else {
+			let q = e.target.quaternion;
+			alpha =
+				Math.atan2(2 * q[0] * q[1] + 2 * q[2] * q[3], 1 - 2 * q[1] * q[1] - 2 * q[2] * q[2]) *
+				(180 / Math.PI);
+			if (alpha < 0) alpha += 360;
+		}
+		set(alpha);
+	};
+	if ('AbsoluteOrientationSensor' in window) {
+		var sensor = new window.AbsoluteOrientationSensor({ frequency: 60 }) as any;
+		sensor.addEventListener('reading', updateHeading);
+		sensor.start();
+	} else if (window.DeviceMotionEvent) window.addEventListener('deviceorientation', updateHeading);
+
+	return () => {
+		if ('AbsoluteOrientationSensor' in window) sensor.removeEventListener('reading', updateHeading);
+		window.addEventListener('deviceorientation', updateHeading);
+	};
+});