/* TINY STAR VIEWER      */
/* MOTION SENSOR Ver 2.3 */
/* TYPE:DISPELL CURSED   */
/* Author:K-ARAI         */
/* created on 2026.03.10 */
/* revised on 2026.04.03 */
/* Version 2.3.1         */
/* WITH MIT-LICENSE ,    */
/* USE FREE !!!          */
/* I WELCOME YOUR REPORT */

/* PRIVATE TEST          */
/* QUALIFIED :           */
/* SHARP AQUOS wish      */
/* SHARP AQUOS wish 5    */
/* APPLE iPad 6th-Gen    */
/* ( iPad OS 17.7.10 )   */
/* APPLE iPhone SE       */
/* ( iOS 18.5 )          */

/* CONDITION */
var motion_init = false;
var motion_ios = false;

/* ORIENTATION VAR */
var mobile_alpha = 0;
var mobile_beta = 0;
var mobile_gamma = 0;

/* DETECTED DIRECTION */

var center_vh = 0;
var center_vd = 0;

var tilt_b = 0;
var tilt_g = 0;

/* ACTIVATION */

function MotionActivate() {

    if(window.DeviceOrientationEvent != undefined ) {
        // iOS 13
        if(window.DeviceOrientationEvent.requestPermission != undefined ) {
            window.DeviceOrientationEvent.requestPermission().then( (permission) => {
                if(permission === "granted" ) {
                    window.addEventListener("deviceorientation",handle_orientation);
                    motion_init = true;
                    motion_ios = true;
                }
            });
        } else {
            window.addEventListener("deviceorientationabsolute",handle_orientation);
            motion_init = true;
        }
    }

}

/* VECTOR CHECKER */

let initial_skip = 5;

let screen_angle = null;

let alpha_sign = null;
let last_alpha = null;
let alpha_cnt = 0;

let beta_sign = null;
let last_beta = null;
let beta_cnt = 0;

let gamma_sign = null;
let last_gamma = null;
let gamma_cnt = 0;

/* MANUAL RESET */

function reset_sensor() {

    alpha_sign = null;
    last_alpha = null;
    alpha_cnt = 0;

    beta_sign = null;
    last_beta = null;
    beta_cnt = 0;

    gamma_sign = null;
    last_gamma = null;
    gamma_cnt = 0;

}

/* HANDLE MOTION */

function handle_orientation(event) {

    let a = event.alpha;
    let b = event.beta;
    let g = event.gamma;

    // Evil spirits, begone!
    if (a == null || b == null || g == null) return;
    if (isNaN(a) || isNaN(b) || isNaN(g)) return;
    if (a === 0 && b === 0 && g === 0) return;

    // 機種ごとの座標系を学習判定

    // alpha の回転方向を判定
    if (last_alpha !== null && alpha_sign === null) {
        let diff = a - last_alpha;
        // １周跨ぎに気を付けろ！
        if (Math.abs(diff) > 1 && Math.abs(diff) < 17) {
            if(++alpha_cnt > initial_skip) {
                alpha_sign = (diff > 0) ? +1 : -1;
            }
        }
    }
    last_alpha = a;

    // beta の符号を端末ごとに自動判定
    if (last_beta !== null && beta_sign === null) {
        let diff = b - last_beta;
        if (Math.abs(diff) > 1) {
            if(++beta_cnt > initial_skip) {
                beta_sign = (diff > 0) ? +1 : -1;
            }
        }
    }
    last_beta = b;

    // gamma の符号も端末ごとに自動判定 ← NEW!!
    if (last_gamma !== null && gamma_sign === null) {
        let diff = g - last_gamma;
        if (Math.abs(diff) > 1) {
            if(++gamma_cnt > initial_skip) {
                gamma_sign = (diff > 0) ? +1 : -1;
            }
        }
    }
    last_gamma = g;

    // 座標軸を揃える
    mobile_alpha  = (alpha_sign || 1) * a;
    mobile_beta   = (beta_sign  || 1) * b;
    mobile_gamma  = (gamma_sign || 1) * g;

    tilt_b = mobile_beta;
    tilt_g = mobile_gamma;

    //  端末の持ち方：画面の向き
    let screenAngle =
        (screen.orientation && screen.orientation.angle) ||
        window.orientation || 0;

    const ua = navigator.userAgent || "";
    const platform = navigator.platform || "";
    const maxTouch = navigator.maxTouchPoints || 0;

    const isiOS =
        /iPhone|iPod/.test(ua) ||                     // iPhone / iPod
        (/iPad/.test(ua)) ||                          // 古い iPad
        (platform === "MacIntel" && maxTouch > 1);    // iPadOS（Mac と名乗る iPad）


    const isiPad =
        navigator.userAgent.includes("iPad") ||
        (navigator.platform === "MacIntel" && navigator.maxTouchPoints > 1);

    if(isiOS) { // 嘘ついてるぞ！気を付けろ！
        screenAngle = window.orientation;
        if(screenAngle < 0) screenAngle += 360;
    }

    if(screenAngle != screen_angle) {
        screen_angle = screenAngle;
        reset_sensor();
    }

//    show_screenangle();

    let beta  = mobile_beta;
    let gamma = mobile_gamma;

    // 入れ替わるよ！
    switch (screenAngle) {
        case 0:
            beta  = mobile_beta;
            gamma = mobile_gamma;
            break;
        case 90:
            beta  = -mobile_gamma;
            gamma = -mobile_beta;
            break;
        case 180:
            beta  = -mobile_beta;
            gamma = -mobile_gamma;
            break;
        case 270:
            beta  = mobile_gamma;
            gamma = mobile_beta;
            break;
        default:
            beta  = mobile_beta;
            gamma = mobile_gamma;
            break;
    }

    let alpha_fixed = mobile_alpha;
    let compass_dir = undefined;

    if (isiOS && typeof event.webkitCompassHeading === "number") {
        // iOS 専用：方位
        compass_dir = event.webkitCompassHeading;
    }

    // 最終的な上下角
    center_vh = beta;

    // 最終的な方位：東が０度で右回り
    if(compass_dir != undefined) {
        center_vd = compass_dir + screenAngle - 180;
    } else { 
        center_vd = 270 - alpha_fixed + screenAngle - 90;
    }
    // SAFETY
    if(center_vd<-180) center_vd += 360;
    if(center_vd>+180) center_vd -= 360;

    return;

}