07Coxcomb Chart Fanning Out Petals With a Radius per Value

<main class="stage">
<div class="cxc is-demo" id="cxcRoot">
  <canvas class="cxc__canvas" id="cxcCanvas" width="480" height="300"></canvas>
  <p class="cxc__caption">Divide the angle by the number of items and draw a fan shape, converting each value's size into a radius, so even with the same width, a larger value makes the petal reach further outward.</p>
</div>
</main>

@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-orange);

.cxc {
  position: relative;
  width: min(92vw, calc(160vh - 12.8vw));
  aspect-ratio: 480 / 300;
  margin: 0 auto;
  border-radius: $r-card;
  overflow: hidden;
  box-shadow: $shadow-raised;
  background: $stage-paper;
}

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

.cxc__caption {
  position: absolute;
  left: $sp-3;
  bottom: $sp-3;
  max-width: 78%;
  margin: 0;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(23, 20, 26, .82);
  color: $subject-cream;
  font-weight: 500;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
}

@media (max-width: 340px) {
  .cxc__caption { font-size: 10px; padding: $sp-1 $sp-2; }
}

@media (prefers-reduced-motion: reduce) {
  .cxc { cursor: default; }
}

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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cxc {
  position: relative;
  width: min(92vw, 160vh - 12.8vw);
  aspect-ratio: 480/300;
  margin: 0 auto;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  background: #ffffff;
}

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

.cxc__caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  max-width: 78%;
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(23, 20, 26, 0.82);
  color: #fff7e6;
  font-weight: 500;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
}

@media (max-width: 340px) {
  .cxc__caption {
    font-size: 10px;
    padding: 4px 8px;
  }
}
@media (prefers-reduced-motion: reduce) {
  .cxc {
    cursor: default;
  }
}

(function () {
  // 기법: 항목 수만큼 중심각을 똑같이 나눠 부채꼴(꽃잎) 자리를 만들고, 값의 크기를
  // 반지름 목표치로 환산한다. 매 프레임 꽃잎마다 다른 시작 지연을 둔 완화 곡선으로
  // 반지름을 0에서 목표까지 실제로 다시 계산해 그려 순차로 자라나는 과정을 보여준다.
  var root = document.getElementById('cxcRoot');
  var canvas = document.getElementById('cxcCanvas');
  var ctx = canvas.getContext('2d');
  var wrap = canvas.parentElement;

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
  }

  var CALC_W = 480, CALC_H = 300;
  var LOOP_MS = 2000;

  var rand = seedRand(425071);
  var COUNT = 6;
  var VALUES = [];
  for (var vi = 0; vi < COUNT; vi += 1) VALUES.push(20 + rand() * 80);

  var COXCOMB_PETAL_GAP_DEG = 2;
  var anglePerPetal = (360 - COXCOMB_PETAL_GAP_DEG * COUNT) / COUNT;

  var MIN_R = 18, MAX_R = 130;
  var maxValue = Math.max.apply(null, VALUES);
  var targetRadii = VALUES.map(function (v) { return MIN_R + (v / maxValue) * (MAX_R - MIN_R); });

  function easeOutCubic(x) { return 1 - Math.pow(1 - x, 3); }
  function easeInCubic(x) { return x * x * x; }
  function clamp01(x) { return Math.max(0, Math.min(1, x)); }

  var CENTER_X = CALC_W * 0.5, CENTER_Y = CALC_H * 0.5;
  var FILL_COLORS = ['47,109,246', '194,54,26', '43,157,116', '138,92,214'];
  var INK_STROKE = '23,20,26';

  function radiusAt(i, t) {
    var target = targetRadii[i];
    if (t < 1400) {
      var growProgress = clamp01((t - i * 90) / 500);
      return target * easeOutCubic(growProgress);
    }
    if (t < 1750) return target;
    var shrinkProgress = clamp01((t - 1750) / 200);
    return target * (1 - easeInCubic(shrinkProgress));
  }

  var cw = 480, ch = 300;
  function draw(t) {
    var sx = cw / CALC_W, sy = ch / CALC_H;
    var scale = (sx + sy) / 2;
    ctx.clearRect(0, 0, cw, ch);
    var cx = CENTER_X * sx, cy = CENTER_Y * sy;
    var startDeg = -90;
    for (var i = 0; i < COUNT; i += 1) {
      var r = radiusAt(i, t) * scale;
      var a0 = startDeg * Math.PI / 180;
      var a1 = (startDeg + anglePerPetal) * Math.PI / 180;
      ctx.beginPath();
      ctx.moveTo(cx, cy);
      ctx.arc(cx, cy, r, a0, a1);
      ctx.closePath();
      ctx.fillStyle = 'rgba(' + FILL_COLORS[i % 4] + ',.75)';
      ctx.fill();
      ctx.strokeStyle = 'rgba(' + INK_STROKE + ',.9)';
      ctx.lineWidth = 1;
      ctx.stroke();
      startDeg += anglePerPetal + COXCOMB_PETAL_GAP_DEG;
    }
  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var elapsed = 0;
  if (reduce) root.classList.remove('is-demo');

  function phaseOf(ms) { return reduce ? LOOP_MS * 0.72 : (ms % LOOP_MS); }

  function fit() {
    var r = wrap.getBoundingClientRect();
    cw = Math.max(1, Math.round(r.width));
    ch = Math.max(1, Math.round(r.height));
    canvas.width = cw; canvas.height = ch;
    draw(phaseOf(elapsed));
  }

  var lastTs = null;
  function tick(ts) {
    if (lastTs === null) lastTs = ts;
    var dt = Math.min(ts - lastTs, 48);
    lastTs = ts;
    if (!reduce) elapsed += dt;
    draw(phaseOf(elapsed));
    requestAnimationFrame(tick);
  }
  fit();
  window.addEventListener('resize', fit);
  draw(phaseOf(elapsed));
  requestAnimationFrame(tick);
})();

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

export default function ChartAdvancedCoxcombRadialPetal() {
  const rootRef = useRef<HTMLDivElement>(null);
  const canvasRef = useRef<HTMLCanvasElement>(null);

  useEffect(() => {
    const root = rootRef.current;
    const canvas = canvasRef.current;
    if (!root || !canvas) return;
    const ctx = canvas.getContext("2d");
    if (!ctx) return;
    const wrap = canvas.parentElement as HTMLElement;

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
    }

    const CALC_W = 480, CALC_H = 300;
    const LOOP_MS = 2000;

    const rand = seedRand(425071);
    const COUNT = 6;
    const VALUES: number[] = [];
    for (let vi = 0; vi < COUNT; vi += 1) VALUES.push(20 + rand() * 80);

    const COXCOMB_PETAL_GAP_DEG = 2;
    const anglePerPetal = (360 - COXCOMB_PETAL_GAP_DEG * COUNT) / COUNT;

    const MIN_R = 18, MAX_R = 130;
    const maxValue = Math.max.apply(null, VALUES);
    const targetRadii = VALUES.map(function (v) { return MIN_R + (v / maxValue) * (MAX_R - MIN_R); });

    function easeOutCubic(x: number) { return 1 - Math.pow(1 - x, 3); }
    function easeInCubic(x: number) { return x * x * x; }
    function clamp01(x: number) { return Math.max(0, Math.min(1, x)); }

    const CENTER_X = CALC_W * 0.5, CENTER_Y = CALC_H * 0.5;
    const FILL_COLORS = ["47,109,246", "194,54,26", "43,157,116", "138,92,214"];
    const INK_STROKE = "23,20,26";

    function radiusAt(i: number, t: number) {
      const target = targetRadii[i];
      if (t < 1400) {
        const growProgress = clamp01((t - i * 90) / 500);
        return target * easeOutCubic(growProgress);
      }
      if (t < 1750) return target;
      const shrinkProgress = clamp01((t - 1750) / 200);
      return target * (1 - easeInCubic(shrinkProgress));
    }

    let cw = 480, ch = 300;
    function draw(t: number) {
      const sx = cw / CALC_W, sy = ch / CALC_H;
      const scale = (sx + sy) / 2;
      ctx!.clearRect(0, 0, cw, ch);
      const cx = CENTER_X * sx, cy = CENTER_Y * sy;
      let startDeg = -90;
      for (let i = 0; i < COUNT; i += 1) {
        const r = radiusAt(i, t) * scale;
        const a0 = startDeg * Math.PI / 180;
        const a1 = (startDeg + anglePerPetal) * Math.PI / 180;
        ctx!.beginPath();
        ctx!.moveTo(cx, cy);
        ctx!.arc(cx, cy, r, a0, a1);
        ctx!.closePath();
        ctx!.fillStyle = "rgba(" + FILL_COLORS[i % 4] + ",.75)";
        ctx!.fill();
        ctx!.strokeStyle = "rgba(" + INK_STROKE + ",.9)";
        ctx!.lineWidth = 1;
        ctx!.stroke();
        startDeg += anglePerPetal + COXCOMB_PETAL_GAP_DEG;
      }
    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let elapsed = 0;
    if (reduce) root.classList.remove("is-demo");

    function phaseOf(ms: number) { return reduce ? LOOP_MS * 0.72 : (ms % LOOP_MS); }

    function fit() {
      const r = wrap.getBoundingClientRect();
      cw = Math.max(1, Math.round(r.width));
      ch = Math.max(1, Math.round(r.height));
      canvas!.width = cw; canvas!.height = ch;
      draw(phaseOf(elapsed));
    }

    let lastTs: number | null = null;
    let raf = 0;
    function tick(ts: number) {
      if (lastTs === null) lastTs = ts;
      const dt = Math.min(ts - lastTs, 48);
      lastTs = ts;
      if (!reduce) elapsed += dt;
      draw(phaseOf(elapsed));
      raf = requestAnimationFrame(tick);
    }
    fit();
    window.addEventListener("resize", fit);
    draw(phaseOf(elapsed));
    raf = requestAnimationFrame(tick);

    return () => {
      cancelAnimationFrame(raf);
      window.removeEventListener("resize", fit);
    };
  }, []);

  return (
    <main className={styles.stage}>
      <div className={`${styles.cxc} is-demo`} ref={rootRef}>
        <canvas className={styles.cxc__canvas} ref={canvasRef} width={480} height={300} />
        <p className={styles.cxc__caption}>항목 수만큼 각도를 나눠 부채꼴을 그리고 값의 크기를 반지름으로 환산해, 같은 폭이라도 값이 클수록 꽃잎이 바깥까지 뻗는다.</p>
      </div>
    </main>
  );
}