07Cells That Even Out as the Iteration-count Value Grows

<main class="stage">
<div class="vd is-demo" id="vdRoot">
  <canvas class="vd__canvas" id="vdCanvas" width="480" height="300"></canvas>
  <p class="vd__caption">Cells That Even Out as the Iteration-count Value Grows</p> <span class="vd__step" id="vdStep">Refining 0/6</span>
</div>
</main>

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

.vd {
  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;
}

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

.vd__caption {
  position: absolute;
  left: $sp-3;
  bottom: $sp-3;
  max-width: 72%;
  margin: 0;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 247, 230, .85);
  color: $subject-ink;
  font-weight: 500;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
}

.vd__step {
  position: absolute;
  right: $sp-3;
  top: $sp-3;
  margin: 0;
  padding: $sp-1 $sp-3;
  border-radius: $r-pill;
  background: rgba(255, 247, 230, .85);
  color: $subject-ink;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  pointer-events: none;
}

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

@media (prefers-reduced-motion: reduce) {
  .vd { 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);
}

.vd {
  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);
}

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

.vd__caption {
  position: absolute;
  left: 12px;
  bottom: 12px;
  max-width: 72%;
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.85);
  color: #17141a;
  font-weight: 500;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
}

.vd__step {
  position: absolute;
  right: 12px;
  top: 12px;
  margin: 0;
  padding: 4px 12px;
  border-radius: 999px;
  background: rgba(255, 247, 230, 0.85);
  color: #17141a;
  font-weight: 700;
  font-size: 11px;
  font-variant-numeric: tabular-nums;
  pointer-events: none;
}

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

(function () {
  var root = document.getElementById('vdRoot');
  var canvas = document.getElementById('vdCanvas');
  var ctx = canvas.getContext('2d');
  var wrap = canvas.parentElement;

  var CALC_W = 160, CALC_H = 100;
  var LOOP_MS = 2000;
  var LLOYD_RELAXATION_STEPS = 6;

  function seedRand(seed) {
    var s = seed >>> 0;
    return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
  }
  var rand = seedRand(409071);

  var off = document.createElement('canvas');
  off.width = CALC_W; off.height = CALC_H;
  var octx = off.getContext('2d');
  var offImg = octx.createImageData(CALC_W, CALC_H);
  var offBuf = offImg.data;

  function hexToRgb(hex) {
    var v = parseInt(hex.slice(1), 16);
    return [(v >> 16) & 255, (v >> 8) & 255, v & 255];
  }

  var NEI = -1, ND = 0, ND2 = 0;
  function nearestTwo(px, py, arr) {
    var bd = Infinity, bd2 = Infinity, bi = -1;
    for (var i = 0; i < arr.length; i += 1) {
      var dx = px - arr[i].x, dy = py - arr[i].y, d = dx * dx + dy * dy;
      if (d < bd) { bd2 = bd; bd = d; bi = i; } else if (d < bd2) { bd2 = d; }
    }
    NEI = bi; ND = Math.sqrt(bd); ND2 = Math.sqrt(bd2);
  }

  var relaxPalette = ['#2f6df6', '#ff9ebb', '#4cd4a6', '#b9a0ff', '#6ec8ff', '#fff7e6'];
  var paletteRgb = {};
  relaxPalette.forEach(function (h) { paletteRgb[h] = hexToRgb(h); });
  var SEED_COUNT07 = 22;
  var baseSeeds = [];
  for (var i7 = 0; i7 < SEED_COUNT07; i7 += 1) {
    baseSeeds.push({ x: rand() * CALC_W, y: rand() * CALC_H, c: relaxPalette[i7 % relaxPalette.length] });
  }

  function computeCentroids(positions) {
    var sumX = new Array(positions.length).fill(0);
    var sumY = new Array(positions.length).fill(0);
    var cnt = new Array(positions.length).fill(0);
    for (var y = 0; y < CALC_H; y += 1) {
      for (var x = 0; x < CALC_W; x += 1) {
        nearestTwo(x + 0.5, y + 0.5, positions);
        sumX[NEI] += x + 0.5; sumY[NEI] += y + 0.5; cnt[NEI] += 1;
      }
    }
    return positions.map(function (p, i) {
      if (!cnt[i]) return { x: p.x, y: p.y, c: p.c };
      return { x: sumX[i] / cnt[i], y: sumY[i] / cnt[i], c: p.c };
    });
  }

  var relaxationStates = [baseSeeds];
  (function buildStates() {
    var cur = baseSeeds;
    for (var k = 0; k < LLOYD_RELAXATION_STEPS; k += 1) {
      cur = computeCentroids(cur);
      relaxationStates.push(cur);
    }
  })();

  var stepLabels = ['Refining 0/6', 'Refining 1/6', 'Refining 2/6', 'Refining 3/6', 'Refining 4/6', 'Refining 5/6', 'Refining 6/6'];
  var stepEl = document.getElementById('vdStep');

  function renderField(t) {
    var frac = (t % LOOP_MS) / LOOP_MS;
    var segFloat = frac * LLOYD_RELAXATION_STEPS;
    var seg = Math.min(LLOYD_RELAXATION_STEPS - 1, Math.floor(segFloat));
    var local = segFloat - seg;
    var a = relaxationStates[seg], b = relaxationStates[seg + 1];
    var cur = a.map(function (p, i) {
      return { x: p.x + (b[i].x - p.x) * local, y: p.y + (b[i].y - p.y) * local, c: p.c };
    });
    var idx = 0;
    for (var y = 0; y < CALC_H; y += 1) {
      for (var x = 0; x < CALC_W; x += 1) {
        nearestTwo(x + 0.5, y + 0.5, cur);
        var rgb = paletteRgb[cur[NEI].c];
        var edge = ND2 - ND;
        var dark = edge < 1.5 ? 0.5 + edge / 3 : 1;
        offBuf[idx] = rgb[0] * dark; offBuf[idx + 1] = rgb[1] * dark; offBuf[idx + 2] = rgb[2] * dark; offBuf[idx + 3] = 255;
        idx += 4;
      }
    }
    if (stepEl) stepEl.textContent = stepLabels[Math.min(LLOYD_RELAXATION_STEPS, seg + (local > 0.5 ? 1 : 0))];
  }

  var cw = 480, ch = 300;
  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(lastElapsed);
  }

  var lastElapsed = 0;
  function draw(elapsed) {
    lastElapsed = elapsed;
    renderField(elapsed);
    octx.putImageData(offImg, 0, 0);
    ctx.imageSmoothingEnabled = false;
    ctx.clearRect(0, 0, cw, ch);
    ctx.drawImage(off, 0, 0, CALC_W, CALC_H, 0, 0, cw, ch);

  }

  var reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  var playing = !reduce;
  var elapsed = reduce ? LOOP_MS * 0.97 : 0;
  if (reduce) { 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 >= LOOP_MS) elapsed -= LOOP_MS;
    }
    draw(elapsed);
    requestAnimationFrame(tick);
  }
  fit();
  window.addEventListener('resize', fit);
  draw(elapsed);
  requestAnimationFrame(tick);
})();

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

export default function VoronoiLloydRelaxationConverge() {
  const rootRef = useRef<HTMLDivElement>(null);
  const canvasRef = useRef<HTMLCanvasElement>(null);
  const [stepLabel, setStepLabel] = useState("정리 진행 0/6");

  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;

    const CALC_W = 160, CALC_H = 100;
    const LOOP_MS = 2000;
    const LLOYD_RELAXATION_STEPS = 6;

    function seedRand(seed: number) {
      let s = seed >>> 0;
      return function () { s = (s * 1664525 + 1013904223) >>> 0; return s / 4294967296; };
    }
    const rand = seedRand(409071);

    const off = document.createElement("canvas");
    off.width = CALC_W; off.height = CALC_H;
    const octx = off.getContext("2d") as CanvasRenderingContext2D;
    const offImg = octx.createImageData(CALC_W, CALC_H);
    const offBuf = offImg.data;

    function hexToRgb(hex: string): [number, number, number] {
      const v = parseInt(hex.slice(1), 16);
      return [(v >> 16) & 255, (v >> 8) & 255, v & 255];
    }

    type Vec = { x: number; y: number };
    let NEI = -1, ND = 0, ND2 = 0;
    function nearestTwo<T extends Vec>(px: number, py: number, arr: T[]): void {
      let bd = Infinity, bd2 = Infinity, bi = -1;
      for (let i = 0; i < arr.length; i += 1) {
        const dx = px - arr[i].x, dy = py - arr[i].y, d = dx * dx + dy * dy;
        if (d < bd) { bd2 = bd; bd = d; bi = i; } else if (d < bd2) { bd2 = d; }
      }
      NEI = bi; ND = Math.sqrt(bd); ND2 = Math.sqrt(bd2);
    }

    type Seed = { x: number; y: number; c: string };
    const relaxPalette = ["#2f6df6", "#ff9ebb", "#4cd4a6", "#b9a0ff", "#6ec8ff", "#fff7e6"];
    const paletteRgb: Record<string, [number, number, number]> = {};
    relaxPalette.forEach((h) => { paletteRgb[h] = hexToRgb(h); });
    const SEED_COUNT07 = 22;
    const baseSeeds: Seed[] = [];
    for (let i7 = 0; i7 < SEED_COUNT07; i7 += 1) {
      baseSeeds.push({ x: rand() * CALC_W, y: rand() * CALC_H, c: relaxPalette[i7 % relaxPalette.length] });
    }

    function computeCentroids(positions: Seed[]): Seed[] {
      const sumX = new Array(positions.length).fill(0);
      const sumY = new Array(positions.length).fill(0);
      const cnt = new Array(positions.length).fill(0);
      for (let y = 0; y < CALC_H; y += 1) {
        for (let x = 0; x < CALC_W; x += 1) {
          nearestTwo(x + 0.5, y + 0.5, positions);
          sumX[NEI] += x + 0.5; sumY[NEI] += y + 0.5; cnt[NEI] += 1;
        }
      }
      return positions.map((p, i) => {
        if (!cnt[i]) return { x: p.x, y: p.y, c: p.c };
        return { x: sumX[i] / cnt[i], y: sumY[i] / cnt[i], c: p.c };
      });
    }

    const relaxationStates: Seed[][] = [baseSeeds];
    (function buildStates() {
      let cur = baseSeeds;
      for (let k = 0; k < LLOYD_RELAXATION_STEPS; k += 1) {
        cur = computeCentroids(cur);
        relaxationStates.push(cur);
      }
    })();

    const stepLabels = ["정리 진행 0/6", "정리 진행 1/6", "정리 진행 2/6", "정리 진행 3/6", "정리 진행 4/6", "정리 진행 5/6", "정리 진행 6/6"];

    function renderField(t: number) {
      const frac = (t % LOOP_MS) / LOOP_MS;
      const segFloat = frac * LLOYD_RELAXATION_STEPS;
      const seg = Math.min(LLOYD_RELAXATION_STEPS - 1, Math.floor(segFloat));
      const local = segFloat - seg;
      const a = relaxationStates[seg], b = relaxationStates[seg + 1];
      const cur: Seed[] = a.map((p, i) => ({
        x: p.x + (b[i].x - p.x) * local, y: p.y + (b[i].y - p.y) * local, c: p.c
      }));
      let idx = 0;
      for (let y = 0; y < CALC_H; y += 1) {
        for (let x = 0; x < CALC_W; x += 1) {
          nearestTwo(x + 0.5, y + 0.5, cur);
          const rgb = paletteRgb[cur[NEI].c];
          const edge = ND2 - ND;
          const dark = edge < 1.5 ? 0.5 + edge / 3 : 1;
          offBuf[idx] = rgb[0] * dark; offBuf[idx + 1] = rgb[1] * dark; offBuf[idx + 2] = rgb[2] * dark; offBuf[idx + 3] = 255;
          idx += 4;
        }
      }
      setStepLabel(stepLabels[Math.min(LLOYD_RELAXATION_STEPS, seg + (local > 0.5 ? 1 : 0))]);
    }

    let cw = 480, ch = 300;
    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(lastElapsed);
    }

    let lastElapsed = 0;
    function draw(elapsed: number) {
      lastElapsed = elapsed;
      renderField(elapsed);
      octx.putImageData(offImg, 0, 0);
      ctx!.imageSmoothingEnabled = false;
      ctx!.clearRect(0, 0, cw, ch);
      ctx!.drawImage(off, 0, 0, CALC_W, CALC_H, 0, 0, cw, ch);

    }

    const reduce = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
    let playing = !reduce;
    let elapsed = reduce ? LOOP_MS * 0.97 : 0;
    if (reduce) { 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 >= LOOP_MS) elapsed -= LOOP_MS;
      }
      draw(elapsed);
      raf = requestAnimationFrame(tick);
    }
    fit();
    window.addEventListener("resize", fit);
    draw(elapsed);
    raf = requestAnimationFrame(tick);

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

    };

  }, []);

  return (
    <main className={styles.stage}>
      <div className={`${styles.vd} is-demo`} ref={rootRef}>
        <canvas className={styles.vd__canvas} ref={canvasRef} width={480} height={300} />
        <p className={styles.vd__caption}>반복 횟수 값이 늘수록 고르게 정돈되는 셀</p>
        <p className={styles.vd__step}>{stepLabel}</p>
      </div>
    </main>
  );
}