09Check draw

<main class="stage">
  <p class="confirm">
    <svg class="confirm__icon" viewBox="0 0 24 24" width="64" height="64" aria-hidden="true">
      <circle cx="12" cy="12" r="10" fill="none" stroke="currentColor" stroke-width="2" opacity=".35"/>
      <polyline class="confirm__trail" points="7 12.5 10.5 16 17 8.5" pathLength="100" fill="none" stroke="currentColor" stroke-width="3.2" stroke-linecap="round" stroke-linejoin="round"/>
      <polyline class="confirm__check" points="7 12.5 10.5 16 17 8.5" pathLength="100" fill="none" stroke="currentColor" stroke-width="3.2" stroke-linecap="round" stroke-linejoin="round"/>
      <circle class="confirm__spark" r="1" cx="7" cy="12.5"/>
      <circle class="confirm__bit" r=".6" cx="7" cy="12.5" style="--dx:-1.8px;--dy:1.4px"/>
      <circle class="confirm__bit" r=".5" cx="7" cy="12.5" style="--dx:-1.2px;--dy:-1.8px"/>
      <circle class="confirm__bit" r=".5" cx="7" cy="12.5" style="--dx:1.4px;--dy:-1.6px"/>
    </svg>
    Saved
  </p>
</main>

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

// ── 변수 3개 ──────────────────────────────
$duration: $dur-base;   // 300ms — 한 바퀴(그리기→멈춤→지우기)
$easing: $ease-out;
$color: $subject-cream;

// ── 데모 무대 ───────────────────────────────
@include stage($stage-ink);

.confirm {
  margin: 0;
  display: inline-flex; align-items: center; gap: clamp($sp-2, 3vw, $sp-3);
  color: $color; font-weight: 600; font-size: clamp(14px, 4vw, 18px); line-height: 1; font-family: inherit;
}
.confirm__icon { color: $color; }
.confirm__check {
  stroke-dasharray: 100;                 // pathLength="100"
  animation: draw $duration $easing infinite;
}

@keyframes draw {
  0%   { stroke-dashoffset: 100; }
  55%  { stroke-dashoffset: 0; }
  80%  { stroke-dashoffset: 0; }
  100% { stroke-dashoffset: -100; }
}

// ── 한 겹: 펜 끝 스파크 + 미광 잔상 ──────────────────────
.confirm__trail {
  fill: none; stroke: currentColor; stroke-width: 3.2;
  stroke-linecap: round; stroke-linejoin: round;
  stroke-dasharray: 100;
  animation: trail-fade $duration $easing infinite;
}
@keyframes trail-fade {
  0%   { stroke-dashoffset: 100; opacity: .45; }
  55%  { stroke-dashoffset: 0;   opacity: .45; }
  85%  { stroke-dashoffset: 0;   opacity: .45; }
  100% { stroke-dashoffset: -100; opacity: 0; }
}

.confirm__spark {
  fill: currentColor;
  opacity: 0;
  transform: scale(1.5); transform-origin: center; transform-box: fill-box;
  filter: drop-shadow(0 0 1px currentColor);
}

.confirm__bit {
  fill: currentColor;
  opacity: 0;
  animation: bit-fly 380ms $ease-out forwards;
}
@keyframes bit-fly {
  0%   { opacity: .9; transform: translate(0, 0) scale(1); }
  100% { opacity: 0;  transform: translate(var(--dx), var(--dy)) scale(.3); }
}

// ── 접근성: 움직임 줄이기 설정이면 완성된 체크만 남긴다 ──────
@media (prefers-reduced-motion: reduce) {
  .confirm__check { animation: none; stroke-dashoffset: 0; }
  .confirm__trail { display: none; }
  .confirm__spark { display: none; }
  .confirm__bit   { display: none; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.confirm {
  margin: 0;
  display: inline-flex;
  align-items: center;
  gap: clamp(8px, 3vw, 12px);
  color: #fff7e6;
  font-weight: 600;
  font-size: clamp(14px, 4vw, 18px);
  line-height: 1;
  font-family: inherit;
}

.confirm__icon {
  color: #fff7e6;
}

.confirm__check {
  stroke-dasharray: 100;
  animation: draw 300ms ease-out infinite;
}

@keyframes draw {
  0% {
    stroke-dashoffset: 100;
  }
  55% {
    stroke-dashoffset: 0;
  }
  80% {
    stroke-dashoffset: 0;
  }
  100% {
    stroke-dashoffset: -100;
  }
}
.confirm__trail {
  fill: none;
  stroke: currentColor;
  stroke-width: 3.2;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-dasharray: 100;
  animation: trail-fade 300ms ease-out infinite;
}

@keyframes trail-fade {
  0% {
    stroke-dashoffset: 100;
    opacity: 0.45;
  }
  55% {
    stroke-dashoffset: 0;
    opacity: 0.45;
  }
  85% {
    stroke-dashoffset: 0;
    opacity: 0.45;
  }
  100% {
    stroke-dashoffset: -100;
    opacity: 0;
  }
}
.confirm__spark {
  fill: currentColor;
  opacity: 0;
  transform: scale(1.5);
  transform-origin: center;
  transform-box: fill-box;
  filter: drop-shadow(0 0 1px currentColor);
}

.confirm__bit {
  fill: currentColor;
  opacity: 0;
  animation: bit-fly 380ms ease-out forwards;
}

@keyframes bit-fly {
  0% {
    opacity: 0.9;
    transform: translate(0, 0) scale(1);
  }
  100% {
    opacity: 0;
    transform: translate(var(--dx), var(--dy)) scale(0.3);
  }
}
@media (prefers-reduced-motion: reduce) {
  .confirm__check {
    animation: none;
    stroke-dashoffset: 0;
  }
  .confirm__trail {
    display: none;
  }
  .confirm__spark {
    display: none;
  }
  .confirm__bit {
    display: none;
  }
}

// 체크 드로잉 한 겹 — 그려지는 동안 펜 끝을 추적해 스파크를 옮기고 찌꺼기를 뿌린다.
// getTotalLength 실측 + getPointAtLength 계산. 지워지는 구간(offset<0)은 시작점 쪽 경계를 따른다.
(function () {
  var svg = document.querySelector('.confirm__icon');
  if (!svg) return;
  var check = svg.querySelector('.confirm__check');
  var spark = svg.querySelector('.confirm__spark');
  var bits = [].slice.call(svg.querySelectorAll('.confirm__bit'));
  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  if (reduce || !spark || !check.getTotalLength) { if (spark) spark.style.display = 'none'; return; }

  var L = check.getTotalLength();
  var prev = null, lastEmit = 0, emitIdx = 0;
  function frame(t) {
    var off = parseFloat(getComputedStyle(check).strokeDashoffset) || 0;
    var at = off >= 0 ? 100 - off : -off;
    var p = check.getPointAtLength(Math.max(0, Math.min(100, at)) / 100 * L);
    if (prev && (Math.abs(p.x - prev.x) + Math.abs(p.y - prev.y)) > .05) {
      spark.setAttribute('cx', p.x);
      spark.setAttribute('cy', p.y);
      spark.style.opacity = 1;
      if (t - lastEmit > 40) {   // 체크는 짧아서 방출 간격도 짧게
        lastEmit = t;
        var ang = Math.atan2(p.y - prev.y, p.x - prev.x) + Math.PI;
        var sp = .4 + Math.random() * .5;
        var b = bits[emitIdx++ % bits.length];
        b.setAttribute('cx', p.x);
        b.setAttribute('cy', p.y);
        b.style.setProperty('--dx', (Math.cos(ang) * sp * 4).toFixed(2) + 'px');
        b.style.setProperty('--dy', (Math.sin(ang) * sp * 4).toFixed(2) + 'px');
        b.style.animation = 'none';
        void b.getBBox;
        b.style.animation = '';
        b.style.animationName = 'bit-fly';
      }
      prev = p;
    } else {
      if (prev) spark.style.opacity = 0;
      if (!prev) prev = p;
    }
    requestAnimationFrame(frame);
  }
  requestAnimationFrame(frame);
})();

import { useEffect, useRef } from "react";
import type { CSSProperties } from "react";
import styles from "./CheckDraw.module.scss";

export type CheckDrawProps = {
  label?: string;
  /** 한 바퀴(그리기→멈춤→지우기) 시간, ms */
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--color"?: string };

const BIT_DIRS: Array<[number, number]> = [
  [-1.8, 1.4],
  [-1.2, -1.8],
  [1.4, -1.6],
];

export default function CheckDraw({
  label = "저장 완료",
  duration = 300,
  easing = "ease-out",
  color = "#fff7e6",
}: CheckDrawProps) {
  const checkRef = useRef<SVGPolylineElement>(null);
  const sparkRef = useRef<SVGCircleElement>(null);
  const bitRefs = useRef<Array<SVGCircleElement | null>>([]) as unknown as { current: Array<SVGCircleElement | null> };

  // 한 겹: 펜 끝 추적 — getTotalLength 실측 + getPointAtLength 로 스파크를 옮기고
  // 진행 반대 방향으로 찌꺼기를 뿌린다. 지워지는 구간(offset<0)은 시작점 쪽 경계를 따른다
  // (vanilla 데모와 동일 계산)
  useEffect(() => {
    const check = checkRef.current, spark = sparkRef.current;
    if (!check || !spark || !check.getTotalLength) return;
    if (window.matchMedia("(prefers-reduced-motion: reduce)").matches) return;
    const L = check.getTotalLength();
    const bits = bitRefs.current.filter(Boolean) as SVGCircleElement[];
    let prev: DOMPoint | null = null, lastEmit = 0, emitIdx = 0, raf = 0;

    const frame = (t: number) => {
      const off = parseFloat(getComputedStyle(check).strokeDashoffset) || 0;
      const at = off >= 0 ? 100 - off : -off;
      const p = check.getPointAtLength(Math.max(0, Math.min(100, at)) / 100 * L);
      if (prev && Math.abs(p.x - prev.x) + Math.abs(p.y - prev.y) > 0.05) {
        spark.setAttribute("cx", String(p.x));
        spark.setAttribute("cy", String(p.y));
        spark.style.opacity = "1";
        if (t - lastEmit > 40 && bits.length) {   // 체크는 짧아서 방출 간격도 짧게
          lastEmit = t;
          const ang = Math.atan2(p.y - prev.y, p.x - prev.x) + Math.PI;
          const sp = 0.4 + Math.random() * 0.5;
          const b = bits[emitIdx++ % bits.length];
          b.setAttribute("cx", String(p.x));
          b.setAttribute("cy", String(p.y));
          b.style.setProperty("--dx", (Math.cos(ang) * sp * 4).toFixed(2) + "px");
          b.style.setProperty("--dy", (Math.sin(ang) * sp * 4).toFixed(2) + "px");
          b.style.animation = "none";
          void b.getBoundingClientRect();
          b.style.animation = "";
        }
        prev = p;
      } else {
        if (prev) spark.style.opacity = "0";
        if (!prev) prev = p;
      }
      raf = requestAnimationFrame(frame);
    };
    raf = requestAnimationFrame(frame);
    return () => cancelAnimationFrame(raf);
  }, []);

  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--color": color };
  return (
    <p className={styles.confirm} style={vars}>
      <svg className={styles.confirm__icon} viewBox="0 0 24 24" width="64" height="64" aria-hidden="true">
        <circle cx="12" cy={12} r={10} fill="none" stroke="currentColor" strokeWidth={2} opacity={0.35} />
        <polyline
          className={styles.confirm__trail}
          points="7 12.5 10.5 16 17 8.5"
          pathLength={100}
          fill="none" stroke="currentColor" strokeWidth={3.2} strokeLinecap="round" strokeLinejoin="round"
        />
        <polyline
          ref={checkRef}
          className={styles.confirm__check}
          points="7 12.5 10.5 16 17 8.5"
          pathLength={100}
          fill="none" stroke="currentColor" strokeWidth={3.2} strokeLinecap="round" strokeLinejoin="round"
        />
        <circle ref={sparkRef} className={styles.confirm__spark} r={1} cx={7} cy={12.5} />
        {BIT_DIRS.map(([dx, dy], i) => (
          <circle
            key={i}
            ref={(el: SVGCircleElement | null) => { bitRefs.current[i] = el; }}
            className={styles.confirm__bit}
            r={i === 0 ? 0.6 : 0.5}
            cx={7}
            cy={12.5}
            style={{ "--dx": `${dx}px`, "--dy": `${dy}px` } as CSSProperties}
          />
        ))}
      </svg>
      {label}
    </p>
  );
}