02Regen-tick glow toggle — each time a value ticks upward at a fixed interval, a flash lights the bar's leading edge

<main class="stage">
<div class="gb is-demo" id="gb">
  <div class="gb__head">
    <span class="gb__label">MP</span>
    <span class="gb__value" id="gbValue">30 / 100</span>
  </div>
  <div class="gb__track" role="progressbar" aria-label="MP" aria-valuemin="0" aria-valuemax="100" aria-valuenow="30" id="gbTrack">
    <div class="gb__fill" id="gbFill"></div>
    <div class="gb__edge" id="gbEdge"></div>
  </div>
  <button type="button" class="gb__hit" id="gbTick">Add Regen Tick</button>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;

// 계산 겹: index.html tick() 이 고정 간격마다 값을 올리고, loop() 은 매 프레임
// 글로우 값을 exp(-dt/GLOW_TAU) 감쇠 공식으로 다시 계산해 밝기·번짐 두 속성에 동시에 먹인다.
@include stage($stage-yellow);

.gb { width: 100%; max-width: 260px; background: $subject-cream; border-radius: $r-card; padding: $sp-5; box-shadow: $shadow-raised; box-sizing: border-box; }
.gb__head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: $sp-3; }
.gb__label { font-size: 12px; font-weight: 700; letter-spacing: .04em; color: rgba($subject-ink, .72); text-transform: uppercase; }
.gb__value { font-size: 15px; font-weight: 700; color: $subject-ink; }

.gb__track { position: relative; height: 18px; border-radius: $r-pill; background: rgba($subject-ink, .1); overflow: visible; }
.gb__fill { position: absolute; left: 0; top: 0; height: 100%; width: 30%; border-radius: $r-pill; background: $subject-mint; will-change: width; }
.gb__edge {
  position: absolute; top: 50%; left: 30%;
  width: 14px; height: 14px; border-radius: 50%;
  background: $subject-mint; transform: translate(-50%, -50%) scale(1);
  box-shadow: 0 0 10px 4px rgba($subject-mint, .8);
  opacity: .35; will-change: opacity, transform;
}

.gb__hit {
  margin-top: $sp-4; width: 100%; border: none; border-radius: $r-control;
  background: $subject-blue; color: $subject-cream;
  font-weight: 700; font-size: 13px; line-height: 1;
  padding: $sp-3 0; cursor: pointer;
}
.gb__hit:active { box-shadow: $shadow-press; }

@media (max-width: 340px) {
  .gb { max-width: 220px; padding: $sp-4; }
  .gb__track { height: 15px; }
  .gb__value { font-size: 13px; }
}

@media (prefers-reduced-motion: reduce) {
  .gb__edge { display: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.gb {
  width: 100%;
  max-width: 260px;
  background: #fff7e6;
  border-radius: 16px;
  padding: 20px;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  box-sizing: border-box;
}

.gb__head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 12px;
}

.gb__label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: rgba(23, 20, 26, 0.72);
  text-transform: uppercase;
}

.gb__value {
  font-size: 15px;
  font-weight: 700;
  color: #17141a;
}

.gb__track {
  position: relative;
  height: 18px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.1);
  overflow: visible;
}

.gb__fill {
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 30%;
  border-radius: 999px;
  background: #4cd4a6;
  will-change: width;
}

.gb__edge {
  position: absolute;
  top: 50%;
  left: 30%;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #4cd4a6;
  transform: translate(-50%, -50%) scale(1);
  box-shadow: 0 0 10px 4px rgba(76, 212, 166, 0.8);
  opacity: 0.35;
  will-change: opacity, transform;
}

.gb__hit {
  margin-top: 16px;
  width: 100%;
  border: none;
  border-radius: 12px;
  background: #2f6df6;
  color: #fff7e6;
  font-weight: 700;
  font-size: 13px;
  line-height: 1;
  padding: 12px 0;
  cursor: pointer;
}

.gb__hit:active {
  box-shadow: 0 6px 12px rgba(23, 20, 26, 0.32);
}

@media (max-width: 340px) {
  .gb {
    max-width: 220px;
    padding: 16px;
  }
  .gb__track {
    height: 15px;
  }
  .gb__value {
    font-size: 13px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .gb__edge {
    display: none;
  }
}

(function () {
  var RES_MAX = 100;
  var START = 30; // 계산 겹 상수: 회복 시작값
  var TICK_INTERVAL = 340; // ms, 자동 루프의 틱 간격
  var TICK_AMOUNT = 7; // 틱마다 오르는 값
  var GLOW_TAU = 150; // ms, 글로우 감쇠 시간상수
  var PAUSE = 500; // ms, 가득 찬 뒤 다음 루프 전 대기
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;

  var gb = document.getElementById('gb');
  var track = document.getElementById('gbTrack');
  var fill = document.getElementById('gbFill');
  var edge = document.getElementById('gbEdge');
  var valueEl = document.getElementById('gbValue');
  var tickBtn = document.getElementById('gbTick');

  var TICK_COUNT = Math.ceil((RES_MAX - START) / TICK_AMOUNT); // 계산 겹: 간격에서 파생
  var CYCLE = TICK_COUNT * TICK_INTERVAL + PAUSE;

  var isDemo = true;
  var value = START;
  var glowStart = -9999;
  var cycleStart = 0;
  var lastTickIdx = -1;

  function render(glow) {
    var v = Math.max(0, Math.min(RES_MAX, value));
    fill.style.width = v.toFixed(2) + '%';
    edge.style.left = v.toFixed(2) + '%';
    var g = glow < 0.02 ? 0 : glow;
    // 계산 겹: 글로우 값이 밝기·번짐 두 CSS 값을 동시에 구동한다
    edge.style.opacity = (0.35 + g * 0.65).toFixed(3);
    edge.style.transform = 'translate(-50%, -50%) scale(' + (1 + g * 0.9).toFixed(3) + ')';
    track.setAttribute('aria-valuenow', String(Math.round(v)));
    valueEl.textContent = Math.round(v) + ' / ' + RES_MAX;
  }

  function tick(ts) {
    value = Math.min(RES_MAX, value + TICK_AMOUNT);
    glowStart = ts;
  }

  function human() {
    if (isDemo) { gb.classList.remove('is-demo'); isDemo = false; }
  }

  tickBtn.addEventListener('click', function () {
    human();
    var now = performance.now();
    if (value >= RES_MAX) { value = START; }
    else { tick(now); }
    render(1);
  });
  tickBtn.addEventListener('keydown', function (ev) {
    if (ev.key !== 'Enter' && ev.key !== ' ') return;
    ev.preventDefault();
    tickBtn.click();
  });

  function loop(ts) {
    if (!cycleStart) cycleStart = ts;
    var elapsed = ts - cycleStart;

    if (isDemo) {
      if (elapsed >= CYCLE) {
        cycleStart = ts; elapsed = 0; value = START; lastTickIdx = -1;
      }
      var idx = Math.floor(elapsed / TICK_INTERVAL);
      if (idx > lastTickIdx && idx < TICK_COUNT) {
        lastTickIdx = idx;
        tick(ts);
      }
    }

    var glow = Math.max(0, Math.exp(-(ts - glowStart) / GLOW_TAU));
    render(glow);
    requestAnimationFrame(loop);
  }

  if (!reduce) {
    requestAnimationFrame(loop);
  } else {
    render(0);
  }
})();

import { useEffect, useRef, useState } from 'react';
import styles from './GaugeBarRegenTickGlow.module.scss';

type Box<T> = { current: T };

const RES_MAX = 100;
const START = 30; // 계산 겹 상수: 회복 시작값
const TICK_INTERVAL = 340; // ms, 자동 루프의 틱 간격
const TICK_AMOUNT = 7; // 틱마다 오르는 값
const GLOW_TAU = 150; // ms, 글로우 감쇠 시간상수
const PAUSE = 500; // ms, 가득 찬 뒤 다음 루프 전 대기
const TICK_COUNT = Math.ceil((RES_MAX - START) / TICK_AMOUNT); // 계산 겹: 간격에서 파생
const CYCLE = TICK_COUNT * TICK_INTERVAL + PAUSE;

export default function GaugeBarRegenTickGlow() {
  const fillRef = useRef(null) as unknown as Box<HTMLDivElement>;
  const edgeRef = useRef(null) as unknown as Box<HTMLDivElement>;
  const trackRef = useRef(null) as unknown as Box<HTMLDivElement>;
  const isDemoRef = useRef(true) as unknown as Box<boolean>;
  const [isDemo, setIsDemo] = useState(true);
  const [value, setValue] = useState(START);

  const valueRef = useRef(START) as unknown as Box<number>;
  const glowStartRef = useRef(-9999) as unknown as Box<number>;

  function human() {
    isDemoRef.current = false;
    setIsDemo(false);
  }

  function tick(ts: number) {
    valueRef.current = Math.min(RES_MAX, valueRef.current + TICK_AMOUNT);
    glowStartRef.current = ts;
  }

  function render(glow: number) {
    const v = Math.max(0, Math.min(RES_MAX, valueRef.current));
    const fill = fillRef.current;
    const edge = edgeRef.current;
    const track = trackRef.current;
    const g = glow < 0.02 ? 0 : glow;
    if (fill) fill.style.width = v.toFixed(2) + '%';
    if (edge) {
      edge.style.left = v.toFixed(2) + '%';
      // 계산 겹: 글로우 값이 밝기·번짐 두 CSS 값을 동시에 구동한다
      edge.style.opacity = (0.35 + g * 0.65).toFixed(3);
      edge.style.transform = 'translate(-50%, -50%) scale(' + (1 + g * 0.9).toFixed(3) + ')';
    }
    if (track) track.setAttribute('aria-valuenow', String(Math.round(v)));
    setValue(Math.round(v));
  }

  useEffect(() => {
    const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
    let cycleStart = 0;
    let lastTickIdx = -1;
    let rafId = 0;

    function loop(ts: number) {
      if (!cycleStart) cycleStart = ts;
      let elapsed = ts - cycleStart;

      if (isDemoRef.current) {
        if (elapsed >= CYCLE) {
          cycleStart = ts; elapsed = 0; valueRef.current = START; lastTickIdx = -1;
        }
        const idx = Math.floor(elapsed / TICK_INTERVAL);
        if (idx > lastTickIdx && idx < TICK_COUNT) {
          lastTickIdx = idx;
          tick(ts);
        }
      }

      const glow = Math.max(0, Math.exp(-(ts - glowStartRef.current) / GLOW_TAU));
      render(glow);
      rafId = requestAnimationFrame(loop);
    }

    if (!reduce) {
      rafId = requestAnimationFrame(loop);
    } else {
      render(0);
    }
    return () => cancelAnimationFrame(rafId);
  }, []);

  function onTick() {
    human();
    if (valueRef.current >= RES_MAX) { valueRef.current = START; }
    else { tick(performance.now()); }
    render(1);
  }

  function onKeyDown(e: { key: string; preventDefault: () => void }) {
    if (e.key !== 'Enter' && e.key !== ' ') return;
    e.preventDefault();
    onTick();
  }

  return (
    <div className={`${styles.gb} ${isDemo ? styles.isDemo : ''}`}>
      <div className={styles.gbHead}>
        <span className={styles.gbLabel}>MP</span>
        <span className={styles.gbValue}>{value} / {RES_MAX}</span>
      </div>
      <div
        className={styles.gbTrack}
        role="progressbar"
        aria-label="MP"
        aria-valuemin={0}
        aria-valuemax={100}
        aria-valuenow={value}
        ref={trackRef}
      >
        <div className={styles.gbFill} ref={fillRef} />
        <div className={styles.gbEdge} ref={edgeRef} />
      </div>
      <button type="button" className={styles.gbHit} onClick={onTick} onKeyDown={onKeyDown}>
        회복 틱 넣기
      </button>
    </div>
  );
}