03Pleats Radiating From One Point and Folding Like a Fan
A sine pleat is multiplied onto radial angles from one point to set each fold's width. Brightness steps between pleats raise a fan pattern like folded cloth.
Best forEvent banners and invitation headers
RADIANT_KPLEAT_FREQFOLD_CONTRAST
<main class="stage">
<div class="hs is-demo" id="hs">
<canvas class="hs__canvas" data-role="canvas" width="480" height="300" tabindex="0" aria-label="Pleats radiating from one point and folding like a fan"></canvas>
<p class="hs__status" data-role="status" aria-live="off">The fan grain turns while folded</p>
<div class="hs__tools">
<button class="hs__btn" data-role="btn" type="button">Reset the fan</button>
</div>
</div>
</main>@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-paper);
.hs {
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: $subject-ink;
}
.hs__canvas {
display: block;
width: 100%;
height: 100%;
cursor: crosshair;
}
.hs__canvas:focus-visible {
outline: 2px solid rgba(58, 48, 76, .9);
outline-offset: -6px;
}
.hs__status {
position: absolute;
left: $sp-3;
bottom: $sp-3;
max-width: 46%;
margin: 0;
padding: $sp-1 $sp-3;
border-radius: $r-control;
background: rgba(255, 252, 244, .92);
color: $subject-ink;
font: inherit;
font-weight: 500;
font-size: 11px;
line-height: 1.4;
pointer-events: none;
}
.hs__tools {
position: absolute;
right: $sp-3;
bottom: $sp-3;
display: flex;
gap: $sp-2;
}
.hs__btn {
margin: 0;
padding: $sp-1 $sp-3;
border: 0;
border-radius: $r-pill;
background: rgba(255, 252, 244, .92);
color: $subject-ink;
font: inherit;
font-weight: 500;
font-size: 12px;
line-height: 1.4;
cursor: pointer;
transition: background-color $dur-quick ease-out;
}
.hs__btn:hover {
background: $subject-cream;
}
.hs__btn[aria-pressed="true"] {
background: $subject-mint;
}
.hs__btn:focus-visible {
outline: 2px solid rgba(58, 48, 76, .9);
outline-offset: 2px;
}
// 포인터로는 잉크를 다루고, 쓸어 넘기는 손가락 제스처는 브라우저에 남겨 페이지 스크롤이 막히지 않게 한다
.hs__canvas { touch-action: pan-y; }
@media (max-width: 340px) {
.hs__btn { font-size: 10px; padding: $sp-1 $sp-2; }
.hs__status { font-size: 10px; padding: $sp-1 $sp-2; }
}
@media (prefers-reduced-motion: reduce) {
.hs__btn { transition: none; }
}html, body {
margin: 0;
overflow: hidden;
}
.stage {
box-sizing: border-box;
min-height: 100vh;
display: grid;
place-items: center;
margin: 0;
background: #ffffff;
font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
padding: clamp(8px, 4vw, 24px);
}
.hs {
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: #17141a;
}
.hs__canvas {
display: block;
width: 100%;
height: 100%;
cursor: crosshair;
}
.hs__canvas:focus-visible {
outline: 2px solid rgba(58, 48, 76, 0.9);
outline-offset: -6px;
}
.hs__status {
position: absolute;
left: 12px;
bottom: 12px;
max-width: 46%;
margin: 0;
padding: 4px 12px;
border-radius: 12px;
background: rgba(255, 252, 244, 0.92);
color: #17141a;
font: inherit;
font-weight: 500;
font-size: 11px;
line-height: 1.4;
pointer-events: none;
}
.hs__tools {
position: absolute;
right: 12px;
bottom: 12px;
display: flex;
gap: 8px;
}
.hs__btn {
margin: 0;
padding: 4px 12px;
border: 0;
border-radius: 999px;
background: rgba(255, 252, 244, 0.92);
color: #17141a;
font: inherit;
font-weight: 500;
font-size: 12px;
line-height: 1.4;
cursor: pointer;
transition: background-color 220ms ease-out;
}
.hs__btn:hover {
background: #fff7e6;
}
.hs__btn[aria-pressed=true] {
background: #4cd4a6;
}
.hs__btn:focus-visible {
outline: 2px solid rgba(58, 48, 76, 0.9);
outline-offset: 2px;
}
.hs__canvas {
touch-action: pan-y;
}
@media (max-width: 340px) {
.hs__btn {
font-size: 10px;
padding: 4px 8px;
}
.hs__status {
font-size: 10px;
padding: 4px 8px;
}
}
@media (prefers-reduced-motion: reduce) {
.hs__btn {
transition: none;
}
}(function () {
const root = document.getElementById("hs");
if (!root) return;
const W = 480;
const H = 300;
const FIXED_DT = 16;
// 마블링 팔레트 — 종이 물면(PAPER) 위에 파스텔 잉크 결이 흐른다
const PAPER = [252, 246, 234];
const INK = [58, 48, 76];
const MINT = [126, 226, 192];
const SKY = [124, 196, 255];
const LILAC = [190, 164, 255];
const PINK = [255, 160, 190];
const PEACH = [255, 208, 168];
const TINTS = [SKY, PINK, MINT, LILAC, PEACH];
function clamp(v, lo, hi) { return v < lo ? lo : (v > hi ? hi : v); }
function lerp(a, b, k) { return a + (b - a) * k; }
function smooth(x) { const c = clamp(x, 0, 1); return c * c * (3 - 2 * c); }
function rgba(c, a) {
return 'rgba(' + Math.round(c[0]) + ',' + Math.round(c[1]) + ',' + Math.round(c[2]) + ',' + clamp(a, 0, 1).toFixed(3) + ')';
}
function mix(a, b, k) { return [lerp(a[0], b[0], k), lerp(a[1], b[1], k), lerp(a[2], b[2], k)]; }
const canvasEl = root.querySelector('[data-role="canvas"]');
const statusEl = root.querySelector('[data-role="status"]');
const ctxRaw = canvasEl ? canvasEl.getContext('2d') : null;
if (!canvasEl || !ctxRaw || !statusEl) {
return;
}
const cv = canvasEl;
const ctx = ctxRaw;
const status = statusEl;
const reduceQuery = window.matchMedia('(prefers-reduced-motion: reduce)');
const still = reduceQuery.matches;
// 자동 시연 중인가 — 사람이 처음 만지는 순간 시연을 멈추고 상태 줄을 읽어 주기 시작한다
let demo = root.classList.contains('is-demo');
function wake() {
if (!demo) {
return;
}
demo = false;
root.classList.remove('is-demo');
status.setAttribute('aria-live', 'polite');
}
function say(text) {
if (status.textContent !== text) {
status.textContent = text;
}
}
// 시연 시계가 loop 주기 안의 at 시각을 이번 스텝에 막 지났는가
function crossed(t, at, loop) {
const p = t % loop;
return p >= at && p - FIXED_DT < at;
}
function fitCanvas() {
// 캔버스 내부 해상도는 480x300 고정, 배율은 devicePixelRatio 에 상한 2 를 둔다
const dpr = Math.min(window.devicePixelRatio || 1, 2);
cv.width = Math.round(W * dpr);
cv.height = Math.round(H * dpr);
ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
}
function onResize() {
fitCanvas();
draw();
}
fitCanvas();
window.addEventListener('resize', onResize);
// 화면 좌표(CSS px) → 장면 좌표(480x300). 리사이즈 뒤에도 늘 현재 크기로 다시 잰다
function toScene(ev) {
const r = cv.getBoundingClientRect();
return [((ev.clientX - r.left) / r.width) * W, ((ev.clientY - r.top) / r.height) * H];
}
// ── 필드 버퍼(077 방식) — 항목이 정한 낮은 해상도 버퍼에 픽셀 값을 굽고 drawImage 로 부드럽게 확대한다
const small = document.createElement('canvas');
let sctx = null;
let buf = null;
let px = null;
// 종이 결은 시간이 지나도 안 변한다 — 필드를 만들 때 한 번만 구워 두고 픽셀마다 꺼내 쓴다
let grainF = new Float32Array(0);
function initField(nw, nh) {
small.width = nw;
small.height = nh;
const c = small.getContext('2d');
if (!c) {
return;
}
sctx = c;
buf = c.createImageData(nw, nh);
px = buf.data;
grainF = new Float32Array(nw * nh);
for (let y = 0; y < nh; y += 1) {
for (let x = 0; x < nw; x += 1) {
grainF[y * nw + x] = paperGrain(x * W / nw, y * H / nh);
}
}
}
function blitField(nw, nh) {
if (!sctx || !buf) {
return;
}
sctx.putImageData(buf, 0, 0);
ctx.imageSmoothingEnabled = true;
ctx.imageSmoothingQuality = 'high';
ctx.drawImage(small, 0, 0, nw, nh, 0, 0, W, H);
}
// ── 결정적 값노이즈 — 난수 소스를 못 쓰므로 정수 해시로 같은 시드에 같은 값
const SEED = 463;
function hash1(n, seed) {
let h = Math.imul(n ^ seed, 374761393);
h = Math.imul(h ^ (h >>> 13), 1274126177);
return ((h ^ (h >>> 16)) >>> 0) / 4294967296;
}
function hash2(x, y, seed) {
return hash1((Math.imul(x, 73856093) ^ Math.imul(y, 19349663)) | 0, seed);
}
function fade(t) { return t * t * (3 - 2 * t); }
function vnoise2(x, y, seed) {
const xi = Math.floor(x), yi = Math.floor(y);
const u = fade(x - xi), v = fade(y - yi);
const a = hash2(xi, yi, seed), b = hash2(xi + 1, yi, seed);
const c = hash2(xi, yi + 1, seed), d = hash2(xi + 1, yi + 1, seed);
return lerp(lerp(a, b, u), lerp(c, d, u), v);
}
function fbm2(x, y, oct, seed) {
let sum = 0, amp = 0.5, norm = 0, f = 1;
for (let i = 0; i < oct; i += 1) {
sum += vnoise2(x * f, y * f, seed + i * 131) * amp;
norm += amp;
amp *= 0.5;
f *= 2;
}
return sum / norm;
}
// 종이 결 — 옅은 얼룩으로 종이가 느껴지게 하는 바닥 값(0~1)
function paperGrain(x, y) {
return fbm2(x * 0.021, y * 0.021, 3, 71);
}
// 03 부케 — 방사각 사인 주름 접힘 폭 산정 + 결마다 밝기 계단
const RADIANT_K = 1.0; // 방사각 사인 주름 진폭 계수
const PLEAT_FREQ = 15; // 한 바퀴 안의 주름(접힘) 수
const FOLD_CONTRAST = 0.34; // 접힌 결마다 밝기 계단 크기
const DEMO_LOOP = 3600;
const FW = 192;
const FH = 120;
const TXT_TURN = 'The fan grain turns while folded';
const TXT_STEPB = 'Brightness steps at every fold';
const TXT_GUIDE = 'Arrow keys turn the fan';
let fanA = 0.5; // 부채 회전각(rad)
let fanV = 0;
let saidStep = false;
function pleatWidth(r, ang) {
// 방사각 사인 주름 접힘 폭 산정 — 주름 계수 K(f·sin mθ) 가 접힘 폭을 정한다
return RADIANT_K * PLEAT_FREQ * Math.sin(ang);
}
function draw() {
if (!px || !sctx) {
return;
}
const ox = FW * 0.44, oy = FH * 0.94;
let i4 = 0;
for (let y = 0; y < FH; y += 1) {
for (let x = 0; x < FW; x += 1) {
const g = grainF[y * FW + x];
const base = mix(PAPER, INK, g * 0.07 + 0.015);
const dx = x - ox, dy = y - oy;
const r = Math.sqrt(dx * dx + dy * dy);
let col = base;
if (r > 6) {
let ang = Math.atan2(dx, -dy) + fanA;
const w = pleatWidth(r, ang);
// 접힘 좌표 — 주름 폭만큼 각을 눌러 천이 접히는 듯한 밀도를 만든다
const fold = (ang * PLEAT_FREQ + w * 0.5) / Math.PI;
const fr = fold - Math.floor(fold);
// 접힌 면(뒤 절반)은 어둡게 — 경계는 0.12 폭으로 부드럽게 넘어가 계단이 톱니로 깨지지 않는다
const shade = 1 - 0.58 * smooth((fr - 0.44) / 0.12) * (1 - smooth((fr - 0.92) / 0.08));
const tint = TINTS[Math.abs(Math.floor(fold)) % TINTS.length];
const edge = smooth(1 - Math.abs(fr - 0.5) * 2);
let k = smooth(clamp(1 - r / (FH * 0.98), 0, 1)) * 0.8;
// 결마다 밝기 계단 — shade 와 FOLD_CONTRAST 로 접힌 면 사이 계단
const stepB = shade * (1 - FOLD_CONTRAST) + (1 - shade) * FOLD_CONTRAST;
k = k * stepB + edge * 0.06;
if (y > oy - 4) {
k *= smooth((oy - 4 - y) / 14);
}
col = mix(base, tint, clamp(k, 0, 1) * 0.8);
col = mix(col, INK, FOLD_CONTRAST * 0.5 * (1 - shade) / 0.58);
}
px[i4] = col[0];
px[i4 + 1] = col[1];
px[i4 + 2] = col[2];
px[i4 + 3] = 255;
i4 += 4;
}
}
blitField(FW, FH);
// 부챗살 결 — 접힘 폭이 커지는 바깥쪽 잉크 테두리
for (let s = 0; s < PLEAT_FREQ; s += 1) {
const a0 = fanA + (s / PLEAT_FREQ) * Math.PI * 2;
const w = pleatWidth(100, a0);
const a1 = a0 + (0.5 + w * 0.008) * (Math.PI * 2 / PLEAT_FREQ);
const r2 = FH * 0.95;
ctx.beginPath();
ctx.moveTo(ox * W / FW, oy * H / FH);
ctx.lineTo((ox + Math.sin(a1) * r2 * 0.96) * W / FW, (oy - Math.cos(a1) * r2 * 0.96) * H / FH);
ctx.strokeStyle = rgba(INK, 0.16);
ctx.lineWidth = 1;
ctx.stroke();
}
}
function settle() {
fanV = 0;
say(TXT_TURN);
}
function step() {
fanA += fanV * FIXED_DT;
fanV *= 0.965;
if (demo && Math.abs(fanV) > 0.0004) {
if (!saidStep && Math.abs(fanA) > 1.1) {
saidStep = true;
say(TXT_STEPB);
}
else if (!saidStep) {
say(TXT_TURN);
}
}
}
function spin(dir) {
fanV += dir * 0.0023;
if (still) {
fanA += dir * 0.28;
fanV = 0;
draw();
return;
}
say(TXT_TURN);
}
function demoTick(t) {
if (crossed(t, 200, DEMO_LOOP)) {
fanV = 0.0021;
saidStep = false;
}
if (crossed(t, 2000, DEMO_LOOP)) {
fanV = -0.0024;
}
}
initField(FW, FH);
const btn = root.querySelector('[data-role="btn"]');
if (btn) {
btn.addEventListener('click', function () {
wake();
fanA = 0.5;
fanV = 0;
saidStep = false;
if (still) {
draw();
}
say(TXT_TURN);
});
}
cv.addEventListener('pointerdown', function (ev) {
wake();
spin(toScene(ev)[0] < W / 2 ? -1 : 1);
});
cv.addEventListener('keydown', function (ev) {
const k = ev.key;
if (k !== 'ArrowLeft' && k !== 'ArrowRight') {
return;
}
ev.preventDefault();
wake();
spin(k === 'ArrowRight' ? 1 : -1);
});
let rafId = 0;
let lastTs = -1;
let acc = 0;
let clock = 0;
function frame(ts) {
if (lastTs < 0) {
lastTs = ts;
}
// 탭이 숨었다 돌아와도 한 번에 100ms 까지만 따라잡는다 — 순간이동 대신 이어서 움직인다
acc += Math.min(ts - lastTs, 100);
lastTs = ts;
let n = 0;
while (acc >= FIXED_DT && n < 6) {
clock += FIXED_DT;
if (demo) {
demoTick(clock);
}
step();
acc -= FIXED_DT;
n += 1;
}
draw();
rafId = window.requestAnimationFrame(frame);
}
if (still) {
settle();
draw();
}
else {
rafId = window.requestAnimationFrame(frame);
}
return function () {
window.cancelAnimationFrame(rafId);
window.removeEventListener('resize', onResize);
};
})();// MblBouquetFanFoldPleats - vanilla 판(03-mbl-bouquet-fan-fold-pleats) 의 React 포트. 같은 계산을 useEffect 안에서 돌린다.
import { useEffect, useRef } from "react";
import styles from "./MblBouquetFanFoldPleats.module.scss";
const cx = (s: string): string => s.split(" ").map((n) => styles[n] ?? n).join(" ");
export default function MblBouquetFanFoldPleats() {
const rootRef = useRef<HTMLDivElement | null>(null);
useEffect(() => {
const rootEl = rootRef.current;
if (!rootEl) return;
const root: HTMLElement = rootEl;
type RGB = [number, number, number];
const W = 480;
const H = 300;
const FIXED_DT = 16;
// 마블링 팔레트 — 종이 물면(PAPER) 위에 파스텔 잉크 결이 흐른다
const PAPER: RGB = [252, 246, 234];
const INK: RGB = [58, 48, 76];
const MINT: RGB = [126, 226, 192];
const SKY: RGB = [124, 196, 255];
const LILAC: RGB = [190, 164, 255];
const PINK: RGB = [255, 160, 190];
const PEACH: RGB = [255, 208, 168];
const TINTS: RGB[] = [SKY, PINK, MINT, LILAC, PEACH];
function clamp(v: number, lo: number, hi: number): number { return v < lo ? lo : (v > hi ? hi : v); }
function lerp(a: number, b: number, k: number): number { return a + (b - a) * k; }
function smooth(x: number): number { const c = clamp(x, 0, 1); return c * c * (3 - 2 * c); }
function rgba(c: RGB, a: number): string {
return 'rgba(' + Math.round(c[0]) + ',' + Math.round(c[1]) + ',' + Math.round(c[2]) + ',' + clamp(a, 0, 1).toFixed(3) + ')';
}
function mix(a: RGB, b: RGB, k: number): RGB { return [lerp(a[0], b[0], k), lerp(a[1], b[1], k), lerp(a[2], b[2], k)]; }
const canvasEl = root.querySelector('[data-role="canvas"]') as HTMLCanvasElement | null;
const statusEl = root.querySelector('[data-role="status"]') as HTMLElement | null;
const ctxRaw = canvasEl ? canvasEl.getContext('2d') : null;
if (!canvasEl || !ctxRaw || !statusEl) { return; }
const cv: HTMLCanvasElement = canvasEl;
const ctx: CanvasRenderingContext2D = ctxRaw;
const status: HTMLElement = statusEl;
const reduceQuery = window.matchMedia('(prefers-reduced-motion: reduce)');
const still = reduceQuery.matches;
// 자동 시연 중인가 — 사람이 처음 만지는 순간 시연을 멈추고 상태 줄을 읽어 주기 시작한다
let demo = root.classList.contains('is-demo');
function wake(): void {
if (!demo) { return; }
demo = false;
root.classList.remove('is-demo');
status.setAttribute('aria-live', 'polite');
}
function say(text: string): void {
if (status.textContent !== text) { status.textContent = text; }
}
// 시연 시계가 loop 주기 안의 at 시각을 이번 스텝에 막 지났는가
function crossed(t: number, at: number, loop: number): boolean {
const p = t % loop;
return p >= at && p - FIXED_DT < at;
}
function fitCanvas(): void {
// 캔버스 내부 해상도는 480x300 고정, 배율은 devicePixelRatio 에 상한 2 를 둔다
const dpr = Math.min(window.devicePixelRatio || 1, 2);
cv.width = Math.round(W * dpr);
cv.height = Math.round(H * dpr);
ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
}
function onResize(): void {
fitCanvas();
draw();
}
fitCanvas();
window.addEventListener('resize', onResize);
// 화면 좌표(CSS px) → 장면 좌표(480x300). 리사이즈 뒤에도 늘 현재 크기로 다시 잰다
function toScene(ev: PointerEvent): [number, number] {
const r = cv.getBoundingClientRect();
return [((ev.clientX - r.left) / r.width) * W, ((ev.clientY - r.top) / r.height) * H];
}
// ── 필드 버퍼(077 방식) — 항목이 정한 낮은 해상도 버퍼에 픽셀 값을 굽고 drawImage 로 부드럽게 확대한다
const small = document.createElement('canvas');
let sctx: CanvasRenderingContext2D | null = null;
let buf: ImageData | null = null;
let px: Uint8ClampedArray | null = null;
// 종이 결은 시간이 지나도 안 변한다 — 필드를 만들 때 한 번만 구워 두고 픽셀마다 꺼내 쓴다
let grainF: Float32Array = new Float32Array(0);
function initField(nw: number, nh: number): void {
small.width = nw;
small.height = nh;
const c = small.getContext('2d');
if (!c) { return; }
sctx = c;
buf = c.createImageData(nw, nh);
px = buf.data;
grainF = new Float32Array(nw * nh);
for (let y = 0; y < nh; y += 1) {
for (let x = 0; x < nw; x += 1) { grainF[y * nw + x] = paperGrain(x * W / nw, y * H / nh); }
}
}
function blitField(nw: number, nh: number): void {
if (!sctx || !buf) { return; }
sctx.putImageData(buf, 0, 0);
ctx.imageSmoothingEnabled = true;
ctx.imageSmoothingQuality = 'high';
ctx.drawImage(small, 0, 0, nw, nh, 0, 0, W, H);
}
// ── 결정적 값노이즈 — 난수 소스를 못 쓰므로 정수 해시로 같은 시드에 같은 값
const SEED = 463;
function hash1(n: number, seed: number): number {
let h = Math.imul(n ^ seed, 374761393);
h = Math.imul(h ^ (h >>> 13), 1274126177);
return ((h ^ (h >>> 16)) >>> 0) / 4294967296;
}
function hash2(x: number, y: number, seed: number): number {
return hash1((Math.imul(x, 73856093) ^ Math.imul(y, 19349663)) | 0, seed);
}
function fade(t: number): number { return t * t * (3 - 2 * t); }
function vnoise2(x: number, y: number, seed: number): number {
const xi = Math.floor(x), yi = Math.floor(y);
const u = fade(x - xi), v = fade(y - yi);
const a = hash2(xi, yi, seed), b = hash2(xi + 1, yi, seed);
const c = hash2(xi, yi + 1, seed), d = hash2(xi + 1, yi + 1, seed);
return lerp(lerp(a, b, u), lerp(c, d, u), v);
}
function fbm2(x: number, y: number, oct: number, seed: number): number {
let sum = 0, amp = 0.5, norm = 0, f = 1;
for (let i = 0; i < oct; i += 1) {
sum += vnoise2(x * f, y * f, seed + i * 131) * amp;
norm += amp;
amp *= 0.5;
f *= 2;
}
return sum / norm;
}
// 종이 결 — 옅은 얼룩으로 종이가 느껴지게 하는 바닥 값(0~1)
function paperGrain(x: number, y: number): number {
return fbm2(x * 0.021, y * 0.021, 3, 71);
}
// 03 부케 — 방사각 사인 주름 접힘 폭 산정 + 결마다 밝기 계단
const RADIANT_K = 1.0; // 방사각 사인 주름 진폭 계수
const PLEAT_FREQ = 15; // 한 바퀴 안의 주름(접힘) 수
const FOLD_CONTRAST = 0.34; // 접힌 결마다 밝기 계단 크기
const DEMO_LOOP = 3600;
const FW = 192;
const FH = 120;
const TXT_TURN = '부채 결이 접힌 채 돈다';
const TXT_STEPB = '접힘마다 밝기가 계단진다';
const TXT_GUIDE = '화살표로 부채를 돌린다';
let fanA = 0.5; // 부채 회전각(rad)
let fanV = 0;
let saidStep = false;
function pleatWidth(r: number, ang: number): number {
// 방사각 사인 주름 접힘 폭 산정 — 주름 계수 K(f·sin mθ) 가 접힘 폭을 정한다
return RADIANT_K * PLEAT_FREQ * Math.sin(ang);
}
function draw(): void {
if (!px || !sctx) { return; }
const ox = FW * 0.44, oy = FH * 0.94;
let i4 = 0;
for (let y = 0; y < FH; y += 1) {
for (let x = 0; x < FW; x += 1) {
const g = grainF[y * FW + x];
const base = mix(PAPER, INK, g * 0.07 + 0.015);
const dx = x - ox, dy = y - oy;
const r = Math.sqrt(dx * dx + dy * dy);
let col = base;
if (r > 6) {
let ang = Math.atan2(dx, -dy) + fanA;
const w = pleatWidth(r, ang);
// 접힘 좌표 — 주름 폭만큼 각을 눌러 천이 접히는 듯한 밀도를 만든다
const fold = (ang * PLEAT_FREQ + w * 0.5) / Math.PI;
const fr = fold - Math.floor(fold);
// 접힌 면(뒤 절반)은 어둡게 — 경계는 0.12 폭으로 부드럽게 넘어가 계단이 톱니로 깨지지 않는다
const shade = 1 - 0.58 * smooth((fr - 0.44) / 0.12) * (1 - smooth((fr - 0.92) / 0.08));
const tint = TINTS[Math.abs(Math.floor(fold)) % TINTS.length];
const edge = smooth(1 - Math.abs(fr - 0.5) * 2);
let k = smooth(clamp(1 - r / (FH * 0.98), 0, 1)) * 0.8;
// 결마다 밝기 계단 — shade 와 FOLD_CONTRAST 로 접힌 면 사이 계단
const stepB = shade * (1 - FOLD_CONTRAST) + (1 - shade) * FOLD_CONTRAST;
k = k * stepB + edge * 0.06;
if (y > oy - 4) { k *= smooth((oy - 4 - y) / 14); }
col = mix(base, tint, clamp(k, 0, 1) * 0.8);
col = mix(col, INK, FOLD_CONTRAST * 0.5 * (1 - shade) / 0.58);
}
px[i4] = col[0]; px[i4 + 1] = col[1]; px[i4 + 2] = col[2]; px[i4 + 3] = 255;
i4 += 4;
}
}
blitField(FW, FH);
// 부챗살 결 — 접힘 폭이 커지는 바깥쪽 잉크 테두리
for (let s = 0; s < PLEAT_FREQ; s += 1) {
const a0 = fanA + (s / PLEAT_FREQ) * Math.PI * 2;
const w = pleatWidth(100, a0);
const a1 = a0 + (0.5 + w * 0.008) * (Math.PI * 2 / PLEAT_FREQ);
const r2 = FH * 0.95;
ctx.beginPath();
ctx.moveTo(ox * W / FW, oy * H / FH);
ctx.lineTo((ox + Math.sin(a1) * r2 * 0.96) * W / FW, (oy - Math.cos(a1) * r2 * 0.96) * H / FH);
ctx.strokeStyle = rgba(INK, 0.16);
ctx.lineWidth = 1;
ctx.stroke();
}
}
function settle(): void {
fanV = 0;
say(TXT_TURN);
}
function step(): void {
fanA += fanV * FIXED_DT;
fanV *= 0.965;
if (demo && Math.abs(fanV) > 0.0004) {
if (!saidStep && Math.abs(fanA) > 1.1) { saidStep = true; say(TXT_STEPB); }
else if (!saidStep) { say(TXT_TURN); }
}
}
function spin(dir: number): void {
fanV += dir * 0.0023;
if (still) {
fanA += dir * 0.28;
fanV = 0;
draw();
return;
}
say(TXT_TURN);
}
function demoTick(t: number): void {
if (crossed(t, 200, DEMO_LOOP)) { fanV = 0.0021; saidStep = false; }
if (crossed(t, 2000, DEMO_LOOP)) { fanV = -0.0024; }
}
initField(FW, FH);
const btn = root.querySelector('[data-role="btn"]') as HTMLButtonElement | null;
if (btn) {
btn.addEventListener('click', function (): void {
wake();
fanA = 0.5;
fanV = 0;
saidStep = false;
if (still) { draw(); }
say(TXT_TURN);
});
}
cv.addEventListener('pointerdown', function (ev: PointerEvent): void {
wake();
spin(toScene(ev)[0] < W / 2 ? -1 : 1);
});
cv.addEventListener('keydown', function (ev: KeyboardEvent): void {
const k = ev.key;
if (k !== 'ArrowLeft' && k !== 'ArrowRight') { return; }
ev.preventDefault();
wake();
spin(k === 'ArrowRight' ? 1 : -1);
});
let rafId = 0;
let lastTs = -1;
let acc = 0;
let clock = 0;
function frame(ts: number): void {
if (lastTs < 0) { lastTs = ts; }
// 탭이 숨었다 돌아와도 한 번에 100ms 까지만 따라잡는다 — 순간이동 대신 이어서 움직인다
acc += Math.min(ts - lastTs, 100);
lastTs = ts;
let n = 0;
while (acc >= FIXED_DT && n < 6) {
clock += FIXED_DT;
if (demo) { demoTick(clock); }
step();
acc -= FIXED_DT;
n += 1;
}
draw();
rafId = window.requestAnimationFrame(frame);
}
if (still) {
settle();
draw();
} else {
rafId = window.requestAnimationFrame(frame);
}
return function (): void {
window.cancelAnimationFrame(rafId);
window.removeEventListener('resize', onResize);
};
}, []);
return (
<div className={cx("hs") + " is-demo"} ref={rootRef}>
<canvas className={cx("hs__canvas")} data-role="canvas" width={480} height={300} tabIndex={0} aria-label="한 점에서 뻗는 주름이 부채처럼 접히는 부케 결"></canvas>
<p className={cx("hs__status")} data-role="status" aria-live="off">부채 결이 접힌 채 돈다</p>
<div className={cx("hs__tools")}>
<button className={cx("hs__btn")} data-role="btn" type="button">부채 되돌리기</button>
</div>
</div>
);
}03 Pleats Radiating From One Point and Folding Like a Fan — Measured area 72.876% · moving frames 23/23Original by GODRICH · SCSS and React ship in the zip · Marble Effect CSS: 9 Ink, Comb and Agate Patterns
The post this demo lives in
Marble Effect CSS: 9 Ink, Comb and Agate PatternsIn this marble effect css set, ink on water is a thin film held by surface tension — 04 pushes it into skewed wave bands See all demos in this post
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