compass-qibla-direction-code.js

qibla(coordinates) {
    const makkah = {
        latitude: 21.42252,
        longitude: 39.82621
    };

    const term1 = Math.sin(this.degreesToRadians(makkah.longitude) - this.degreesToRadians(coordinates.longitude));
    const term2 = Math.cos(this.degreesToRadians(coordinates.latitude)) * Math.tan(this.degreesToRadians(makkah.latitude));
    const term3 = Math.sin(this.degreesToRadians(coordinates.latitude)) * Math.cos(this.degreesToRadians(makkah.longitude) - this.degreesToRadians(coordinates.longitude));
    const angle = Math.atan2(term1, term2 - term3);
    return this.unwindAngle(this.radiansToDegrees(angle));
},
degreesToRadians(degrees) {
    return degrees * Math.PI / 180.0;
},
radiansToDegrees(radians) {
    return radians * 180.0 / Math.PI;
},
normalizeToScale(number, max) {
    return number - max * Math.floor(number / max);
},
unwindAngle(angle) {
    return this.normalizeToScale(angle, 360.0);
},