02QR Code Whose Corner Frame Blinks While Waiting to Be Read

<main class="stage">
<div class="scf is-demo" id="scfRoot">
  <div class="scf__badge" id="scfBadge">Scanning 0%</div>
  <button class="scf__ctrl" id="scfCtrl" type="button">Pause</button>
  <div class="scf__canvas-wrap">
    <canvas class="scf__canvas" id="scfCanvas" width="240" height="200"></canvas>
  </div>
</div>
</main>

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

// 핵심: 스캔선의 y 좌표와 각 코너 사이 거리로 발광 강도(0~1)를 계산해
// 스캔선이 지나가는 순간에만 모서리 프레임이 밝아지도록 한다.

@include stage($stage-ink);

.scf {
  position: relative;
  width: min(100%, 280px);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: $sp-3;
}

.scf__badge {
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 247, 230, .08);
  color: $subject-cream;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.scf__ctrl {
  position: absolute;
  top: 0;
  right: 0;
  border: 0;
  border-radius: $r-xs;
  padding: $sp-1 $sp-2;
  background: rgba(255, 247, 230, .12);
  color: $subject-cream;
  font-weight: 600;
  font-size: 10px;
  line-height: 1.4;
  cursor: pointer;
}
.scf__ctrl:focus-visible { outline: 2px solid $subject-blue-light; outline-offset: 2px; }

.scf__canvas-wrap {
  width: 100%;
  aspect-ratio: 7 / 5;
  border-radius: $r-card;
  background: rgba(255, 255, 255, .04);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.scf__canvas {
  width: 100%;
  height: 100%;
  display: block;
}

@media (max-width: 340px) {
  .scf { gap: $sp-1; }
  .scf__badge { padding: $sp-1 $sp-2; font-size: 10px; }
  .scf__canvas-wrap { max-width: 150px; aspect-ratio: 3 / 2; margin: 0 auto; }
}

@media (prefers-reduced-motion: reduce) {
  .scf__canvas-wrap { background: rgba(255, 255, 255, .04); }
}

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);
}

.scf {
  position: relative;
  width: min(100%, 280px);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.scf__badge {
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.08);
  color: #fff7e6;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
}

.scf__ctrl {
  position: absolute;
  top: 0;
  right: 0;
  border: 0;
  border-radius: 4px;
  padding: 4px 8px;
  background: rgba(255, 247, 230, 0.12);
  color: #fff7e6;
  font-weight: 600;
  font-size: 10px;
  line-height: 1.4;
  cursor: pointer;
}

.scf__ctrl:focus-visible {
  outline: 2px solid #5b8cf8;
  outline-offset: 2px;
}

.scf__canvas-wrap {
  width: 100%;
  aspect-ratio: 7/5;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.04);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.scf__canvas {
  width: 100%;
  height: 100%;
  display: block;
}

@media (max-width: 340px) {
  .scf {
    gap: 4px;
  }
  .scf__badge {
    padding: 4px 8px;
    font-size: 10px;
  }
  .scf__canvas-wrap {
    max-width: 150px;
    aspect-ratio: 3/2;
    margin: 0 auto;
  }
}
@media (prefers-reduced-motion: reduce) {
  .scf__canvas-wrap {
    background: rgba(255, 255, 255, 0.04);
  }
}

(function () {
  // SCF_CORNER_GLOW_RANGE_PX — 변형 1: 26 → 46 으로 늘리면 코너가 더 일찍, 더 오래 밝아진다.
  var SCF_CORNER_GLOW_RANGE_PX = 26;
  var SWEEP_MS = 1400;
  var SIZE = 15;

  var canvas = document.getElementById('scfCanvas');
  var ctx = canvas.getContext('2d');
  var badge = document.getElementById('scfBadge');
  var ctrl = document.getElementById('scfCtrl');
  var root = document.getElementById('scfRoot');

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () {
      s = (s * 1664525 + 1013904223) >>> 0;
      return s / 4294967296;
    };
  }
  var rand = seedRand(407025);
  var dots = [];
  for (var y = 0; y < SIZE; y += 1) {
    for (var x = 0; x < SIZE; x += 1) {
      if (rand() < 0.4) dots.push({ x: x, y: y });
    }
  }

  function cornerGlow(dist) {
    // 계산 한 겹: 스캔선까지 거리 → 코너 발광 강도(0~1), 범위 밖이면 0
    var p = 1 - dist / SCF_CORNER_GLOW_RANGE_PX;
    return p < 0 ? 0 : (p > 1 ? 1 : p);
  }

  function draw(elapsed) {
    var cw = canvas.width, ch = canvas.height;
    ctx.clearRect(0, 0, cw, ch);

    var pad = 28;
    var boxX = pad, boxY = pad, boxW = cw - pad * 2, boxH = ch - pad * 2;
    var cell = boxW / SIZE;

    ctx.fillStyle = 'rgba(255,247,230,.65)';
    dots.forEach(function (d) {
      var s = cell * 0.55;
      ctx.fillRect(boxX + d.x * cell + (cell - s) / 2, boxY + d.y * cell + (cell - s) / 2, s, s);
    });

    var t = (elapsed % SWEEP_MS) / SWEEP_MS;
    var scanY = boxY + t * boxH;

    var grad = ctx.createLinearGradient(0, scanY - 18, 0, scanY + 18);
    grad.addColorStop(0, 'rgba(120,200,255,0)');
    grad.addColorStop(0.5, 'rgba(120,200,255,.55)');
    grad.addColorStop(1, 'rgba(120,200,255,0)');
    ctx.fillStyle = grad;
    ctx.fillRect(boxX, scanY - 18, boxW, 36);
    ctx.strokeStyle = 'rgba(180,225,255,.9)';
    ctx.lineWidth = 2;
    ctx.beginPath();
    ctx.moveTo(boxX, scanY);
    ctx.lineTo(boxX + boxW, scanY);
    ctx.stroke();

    var corners = [
      { x: boxX, y: boxY, dx: 1, dy: 1 },
      { x: boxX + boxW, y: boxY, dx: -1, dy: 1 },
      { x: boxX, y: boxY + boxH, dx: 1, dy: -1 },
      { x: boxX + boxW, y: boxY + boxH, dx: -1, dy: -1 }
    ];
    var len = 18;
    corners.forEach(function (c) {
      var g = cornerGlow(Math.abs(scanY - c.y));
      var lw = 3 + g * 2.5;
      ctx.strokeStyle = 'rgba(' + (180 + g * 75) + ',' + (225) + ',255,' + (0.55 + g * 0.45) + ')';
      ctx.lineWidth = lw;
      ctx.beginPath();
      ctx.moveTo(c.x, c.y + c.dy * len);
      ctx.lineTo(c.x, c.y);
      ctx.lineTo(c.x + c.dx * len, c.y);
      ctx.stroke();
    });

    badge.textContent = 'Scanning ' + Math.round(t * 100) + '%';
  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var playing = true;
  var elapsed = reduce ? SWEEP_MS : 0;
  if (reduce) {
    playing = false;
    root.classList.remove('is-demo');
  }

  var lastTs = null;
  function tick(ts) {
    if (lastTs === null) lastTs = ts;
    var dt = ts - lastTs;
    lastTs = ts;
    if (playing) {
      elapsed += dt;
      if (elapsed >= SWEEP_MS) elapsed -= SWEEP_MS;
    }
    draw(elapsed);
    requestAnimationFrame(tick);
  }
  draw(elapsed);
  requestAnimationFrame(tick);

  ctrl.addEventListener('click', function () {
    playing = !playing;
    ctrl.textContent = playing ? 'Pause' : 'Play';
  });
  ctrl.addEventListener('keydown', function (e) {
    if ((e.key === 'r' || e.key === 'R') && !reduce) {
      elapsed = 0;
      playing = true;
      ctrl.textContent = 'Pause';
    }
  });
})();

import { useEffect, useRef, useState } from "react";
import styles from "./ScanCornerFrame.module.scss";

export default function ScanCornerFrame() {
  const rootRef = useRef<HTMLDivElement>(null);
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const ctrlRef = useRef<HTMLButtonElement>(null);
  const [badge, setBadge] = useState("스캔 중 0%");
  const [ctrlLabel, setCtrlLabel] = useState("일시정지");

  useEffect(() => {
    const root = rootRef.current;
    const canvas = canvasRef.current;
    const ctrl = ctrlRef.current;
    if (!root || !canvas || !ctrl) return;
    const ctx = canvas.getContext("2d");
    if (!ctx) return;

    // SCF_CORNER_GLOW_RANGE_PX — 변형 1: 26 → 46 으로 늘리면 코너가 더 일찍, 더 오래 밝아진다.
    const SCF_CORNER_GLOW_RANGE_PX = 26;
    const SWEEP_MS = 1400;
    const SIZE = 15;

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () {
        s = (s * 1664525 + 1013904223) >>> 0;
        return s / 4294967296;
      };
    }
    const rand = seedRand(407025);
    const dots: { x: number; y: number }[] = [];
    for (let y = 0; y < SIZE; y += 1) {
      for (let x = 0; x < SIZE; x += 1) {
        if (rand() < 0.4) dots.push({ x, y });
      }
    }

    function cornerGlow(dist: number) {
      // 계산 한 겹: 스캔선까지 거리 → 코너 발광 강도(0~1), 범위 밖이면 0
      const p = 1 - dist / SCF_CORNER_GLOW_RANGE_PX;
      return p < 0 ? 0 : p > 1 ? 1 : p;
    }

    function draw(elapsed: number) {
      const cw = canvas!.width, ch = canvas!.height;
      ctx!.clearRect(0, 0, cw, ch);

      const pad = 28;
      const boxX = pad, boxY = pad, boxW = cw - pad * 2, boxH = ch - pad * 2;
      const cell = boxW / SIZE;

      ctx!.fillStyle = "rgba(255,247,230,.65)";
      dots.forEach((d) => {
        const s = cell * 0.55;
        ctx!.fillRect(boxX + d.x * cell + (cell - s) / 2, boxY + d.y * cell + (cell - s) / 2, s, s);
      });

      const t = (elapsed % SWEEP_MS) / SWEEP_MS;
      const scanY = boxY + t * boxH;

      const grad = ctx!.createLinearGradient(0, scanY - 18, 0, scanY + 18);
      grad.addColorStop(0, "rgba(120,200,255,0)");
      grad.addColorStop(0.5, "rgba(120,200,255,.55)");
      grad.addColorStop(1, "rgba(120,200,255,0)");
      ctx!.fillStyle = grad;
      ctx!.fillRect(boxX, scanY - 18, boxW, 36);
      ctx!.strokeStyle = "rgba(180,225,255,.9)";
      ctx!.lineWidth = 2;
      ctx!.beginPath();
      ctx!.moveTo(boxX, scanY);
      ctx!.lineTo(boxX + boxW, scanY);
      ctx!.stroke();

      const corners = [
        { x: boxX, y: boxY, dx: 1, dy: 1 },
        { x: boxX + boxW, y: boxY, dx: -1, dy: 1 },
        { x: boxX, y: boxY + boxH, dx: 1, dy: -1 },
        { x: boxX + boxW, y: boxY + boxH, dx: -1, dy: -1 },
      ];
      const len = 18;
      corners.forEach((c) => {
        const g = cornerGlow(Math.abs(scanY - c.y));
        const lw = 3 + g * 2.5;
        ctx!.strokeStyle = "rgba(" + (180 + g * 75) + "," + 225 + ",255," + (0.55 + g * 0.45) + ")";
        ctx!.lineWidth = lw;
        ctx!.beginPath();
        ctx!.moveTo(c.x, c.y + c.dy * len);
        ctx!.lineTo(c.x, c.y);
        ctx!.lineTo(c.x + c.dx * len, c.y);
        ctx!.stroke();
      });

      setBadge("스캔 중 " + Math.round(t * 100) + "%");
    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let playing = true;
    let elapsed = reduce ? SWEEP_MS : 0;
    if (reduce) {
      playing = false;
      root.classList.remove("is-demo");
    }

    let lastTs: number | null = null;
    let raf = 0;
    function tick(ts: number) {
      if (lastTs === null) lastTs = ts;
      const dt = ts - lastTs;
      lastTs = ts;
      if (playing) {
        elapsed += dt;
        if (elapsed >= SWEEP_MS) elapsed -= SWEEP_MS;
      }
      draw(elapsed);
      raf = requestAnimationFrame(tick);
    }
    draw(elapsed);
    raf = requestAnimationFrame(tick);

    function onClick() {
      playing = !playing;
      setCtrlLabel(playing ? "일시정지" : "재생");
    }
    function onKeydown(e: KeyboardEvent) {
      if ((e.key === "r" || e.key === "R") && !reduce) {
        elapsed = 0;
        playing = true;
        setCtrlLabel("일시정지");
      }
    }
    ctrl.addEventListener("click", onClick);
    ctrl.addEventListener("keydown", onKeydown);

    return () => {
      cancelAnimationFrame(raf);
      ctrl.removeEventListener("click", onClick);
      ctrl.removeEventListener("keydown", onKeydown);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={`${styles.scf} is-demo`} ref={rootRef}>
        <div className={styles.scf__badge}>{badge}</div>
        <button className={styles.scf__ctrl} type="button" ref={ctrlRef}>{ctrlLabel}</button>
        <div className={styles["scf__canvas-wrap"]}>
          <canvas className={styles.scf__canvas} ref={canvasRef} width={240} height={200} />
        </div>
      </div>
    </main>
  );
}