01A Card Track Where Vertical Wheel Input Becomes Sideways Motion and Friction Slows It After Input Stops
Vertical wheel values are added to a velocity, and each frame that velocity is multiplied by a friction factor. At both ends of the track the position resists like a rubber band and returns.
Best forHorizontal product lists and recommendation card rows
FRICTIONWHEEL_GAINEDGE_KRUBBER_PX
<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="A card track pushed sideways by wheel or drag that slows to a stop through friction and springs back at both ends like a rubber band"></canvas>
<p class="hs__status" data-role="status" aria-live="off">Gliding on wheel inertia</p>
<div class="hs__tools">
<button class="hs__btn" data-role="btn" type="button">Back to start</button>
</div>
</div>
</main>@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-ink);
.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: grab;
}
.hs__canvas:active {
cursor: grabbing;
}
.hs__canvas:focus-visible {
outline: 2px solid rgba(255, 255, 255, .85);
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, 255, 255, .85);
color: $subject-ink;
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, 255, 255, .85);
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(255, 255, 255, .95);
outline-offset: 2px;
}
// 손가락 가로 끌기는 이 캔버스가 받고, 세로 쓸기는 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: #17141a;
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: grab;
}
.hs__canvas:active {
cursor: grabbing;
}
.hs__canvas:focus-visible {
outline: 2px solid rgba(255, 255, 255, 0.85);
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, 255, 255, 0.85);
color: #17141a;
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, 255, 255, 0.85);
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(255, 255, 255, 0.95);
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;
// 파스텔 팔레트 — 어두운 무대 위에 밝은 카드를 얹어 명도 차로 읽힌다
const BG = [29, 26, 44];
const PAPER = [255, 248, 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;
}
}
// 휠 한 번의 이동량을 px 로 — 줄 단위(deltaMode 1)·쪽 단위(deltaMode 2) 장치도 같은 눈금으로 맞춘다.
// 가로·세로 중 큰 쪽을 쓴다: 트랙패드의 가로 쓸기와 마우스 휠의 세로 굴림이 같은 방향으로 들어온다
function wheelPx(ev) {
const unit = ev.deltaMode === 1 ? 16 : (ev.deltaMode === 2 ? W : 1);
const d = Math.abs(ev.deltaX) > Math.abs(ev.deltaY) ? ev.deltaX : ev.deltaY;
return d * unit;
}
// 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() {
const dpr = window.devicePixelRatio || 1;
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];
}
function roundRectPath(c, x, y, w, h, r) {
const rr = Math.min(r, w / 2, h / 2);
c.beginPath();
c.moveTo(x + rr, y);
c.lineTo(x + w - rr, y);
c.quadraticCurveTo(x + w, y, x + w, y + rr);
c.lineTo(x + w, y + h - rr);
c.quadraticCurveTo(x + w, y + h, x + w - rr, y + h);
c.lineTo(x + rr, y + h);
c.quadraticCurveTo(x, y + h, x, y + h - rr);
c.lineTo(x, y + rr);
c.quadraticCurveTo(x, y, x + rr, y);
c.closePath();
}
// 카드 한 장 — 사진 대신 계산한 그림 칸(그라디언트 하늘·해·언덕) + 글줄 막대 두 개 + 번호
function drawCard(c, x, y, w, h, i, light) {
const t1 = TINTS[i % TINTS.length];
const t2 = TINTS[(i + 2) % TINTS.length];
const k = clamp(light, 0, 1);
roundRectPath(c, x, y, w, h, 10);
c.fillStyle = rgba(mix(BG, PAPER, k), 1);
c.fill();
const ih = h * 0.58;
const g = c.createLinearGradient(x, y, x + w, y + ih);
g.addColorStop(0, rgba(mix(BG, t1, k), 1));
g.addColorStop(1, rgba(mix(BG, t2, k * 0.92), 1));
c.save();
roundRectPath(c, x + 6, y + 6, w - 12, ih - 6, 7);
c.fillStyle = g;
c.fill();
c.clip();
c.fillStyle = rgba(mix(BG, PAPER, k * 0.9), 0.9);
c.beginPath();
c.arc(x + w * 0.7, y + ih * 0.36, Math.min(w, ih) * 0.13, 0, Math.PI * 2);
c.fill();
c.fillStyle = rgba(mix(BG, INK, k), 0.55);
c.beginPath();
c.moveTo(x, y + ih);
c.lineTo(x + w * 0.32, y + ih * 0.55);
c.lineTo(x + w * 0.55, y + ih * 0.8);
c.lineTo(x + w * 0.78, y + ih * 0.62);
c.lineTo(x + w, y + ih);
c.closePath();
c.fill();
c.restore();
c.fillStyle = rgba(mix(BG, INK, k), 0.75);
c.fillRect(x + 10, y + ih + 12, w * 0.62, 6);
c.fillStyle = rgba(mix(BG, INK, k), 0.4);
c.fillRect(x + 10, y + ih + 24, w * 0.44, 5);
c.fillStyle = rgba(mix(BG, INK, k), 0.9);
c.font = '700 13px sans-serif';
c.textAlign = 'right';
c.textBaseline = 'alphabetic';
c.fillText(String(i + 1).padStart(2, '0'), x + w - 9, y + h - 10);
}
const CARD_N = 12;
const CARD_W = 118;
const CARD_H = 156;
const GAP = 14;
const PITCH = CARD_W + GAP;
const PAD = 24;
const TRACK_TOP = 58;
const MAX_X = PAD * 2 + CARD_N * PITCH - GAP - W;
const WHEEL_GAIN = 0.12;
const FRICTION = 0.92;
const EDGE_K = 0.16;
const EDGE_DAMP = 0.6;
const RUBBER_PX = 90;
const STOP_V = 0.05;
const DEMO_LOOP = 4200;
const TXT_GLIDE = 'Gliding on wheel inertia';
const TXT_EDGE = 'Springing back from the end like a rubber band';
const TXT_STOP = 'Stopped';
const backBtn = root.querySelector('[data-role="btn"]');
let x = 0;
let v = 0;
let moving = false;
let edgeSaid = false;
let dragId = -1;
let dragX = 0;
let dragT = 0;
let dragV = 0;
// 트랙 끝 밖으로 나간 거리(안쪽이면 0)
function overshoot(p) { return p < 0 ? p : (p > MAX_X ? p - MAX_X : 0); }
// 끝 밖으로 미는 입력은 나간 거리만큼 줄인다 — 고무줄처럼 버틴다
function rubber(d) {
const out = (x <= 0 && d < 0) || (x >= MAX_X && d > 0);
return out ? d / (1 + Math.abs(overshoot(x)) / RUBBER_PX) : d;
}
function push(d) {
v += rubber(d) * WHEEL_GAIN;
moving = true;
say(TXT_GLIDE);
}
// 지금 속도로 놓아두면 얼마나 더 가나 — 스텝마다 FRICTION 을 곱하므로 등비급수 v·f/(1−f)
function glideDistance(v0, f) { return v0 * f / (1 - f); }
// 거꾸로, distance 만큼 가서 멈추려면 처음 속도가 얼마여야 하나
function speedFor(distance, f) { return distance * (1 - f) / f; }
function canMove(d) { return d > 0 ? x < MAX_X - 0.5 : x > 0.5; }
function step() {
if (dragId >= 0) {
return;
}
x += v;
const o = overshoot(x);
if (o !== 0) {
v = (v - o * EDGE_K) * EDGE_DAMP;
if (!edgeSaid) {
edgeSaid = true;
say(TXT_EDGE);
}
}
else {
v *= FRICTION;
edgeSaid = false;
}
if (moving && Math.abs(v) < STOP_V && Math.abs(o) < 0.5) {
x = clamp(x, 0, MAX_X);
v = 0;
moving = false;
say(TXT_STOP);
}
}
function settle() {
x = 0;
v = 0;
say(TXT_STOP);
}
function demoTick(t) {
for (let k = 0; k < 3; k += 1) {
if (crossed(t, 200 + k * 40, DEMO_LOOP)) {
push(100);
}
}
for (let k = 0; k < 5; k += 1) {
if (crossed(t, 1250 + k * 40, DEMO_LOOP)) {
push(-100);
}
}
}
function draw() {
ctx.fillStyle = rgba(BG, 1);
ctx.fillRect(0, 0, W, H);
// 바닥 레일
ctx.fillStyle = rgba(mix(BG, LILAC, 0.16), 1);
ctx.fillRect(0, TRACK_TOP + CARD_H + 14, W, 3);
for (let i = 0; i < CARD_N; i += 1) {
const cx = PAD + i * PITCH - x;
if (cx > W || cx + CARD_W < 0) {
continue;
}
drawCard(ctx, cx, TRACK_TOP, CARD_W, CARD_H, i, 1);
}
// 위쪽 진행 막대 — 끝 밖으로 나가면 막대가 그만큼 짧아진다
const trackW = W - 48;
const thumbW = trackW * (W / (MAX_X + W));
const o = overshoot(x);
const squash = Math.abs(o) * 0.6;
const left = 24 + (clamp(x, 0, MAX_X) / MAX_X) * (trackW - thumbW) + (o > 0 ? squash : 0);
ctx.fillStyle = rgba(mix(BG, PAPER, 0.14), 1);
ctx.fillRect(24, 26, trackW, 6);
ctx.fillStyle = rgba(SKY, 1);
ctx.fillRect(left, 26, Math.max(10, thumbW - squash), 6);
// 속도 눈금 — 마찰로 줄어드는 모습이 그대로 보인다
const speedW = clamp(Math.abs(v) * 2.4, 0, trackW);
ctx.fillStyle = rgba(PINK, 0.9);
ctx.fillRect(W / 2 - speedW / 2, 38, speedW, 3);
}
function onWheel(ev) {
const d = wheelPx(ev);
// 끝에 닿았으면 가로채지 않는다 — 페이지가 계속 스크롤된다
if (d === 0 || !canMove(d)) {
return;
}
ev.preventDefault();
wake();
if (still) {
x = clamp(x + d, 0, MAX_X);
say(TXT_STOP);
draw();
return;
}
push(d);
}
cv.addEventListener('wheel', onWheel, { passive: false });
cv.addEventListener('pointerdown', function (ev) {
wake();
dragId = ev.pointerId;
cv.setPointerCapture(ev.pointerId);
dragX = toScene(ev)[0];
dragT = ev.timeStamp;
dragV = 0;
v = 0;
});
cv.addEventListener('pointermove', function (ev) {
if (ev.pointerId !== dragId) {
return;
}
const sx = toScene(ev)[0];
const dx = sx - dragX;
const steps = Math.max(1, (ev.timeStamp - dragT) / FIXED_DT);
dragX = sx;
dragT = ev.timeStamp;
const d = rubber(-dx);
x = still ? clamp(x + d, 0, MAX_X) : x + d;
dragV = lerp(dragV, d / steps, 0.5);
if (still) {
draw();
}
});
function endDrag(ev) {
if (ev.pointerId !== dragId) {
return;
}
dragId = -1;
if (still) {
return;
}
v = clamp(dragV, -60, 60);
moving = true;
say(TXT_GLIDE);
}
cv.addEventListener('pointerup', endDrag);
cv.addEventListener('pointercancel', endDrag);
cv.addEventListener('keydown', function (ev) {
let goal = NaN;
if (ev.key === 'ArrowRight') {
goal = x + PITCH;
}
else if (ev.key === 'ArrowLeft') {
goal = x - PITCH;
}
else if (ev.key === 'Home') {
goal = 0;
}
else if (ev.key === 'End') {
goal = MAX_X;
}
if (Number.isNaN(goal) || !canMove(goal - x)) {
return;
}
ev.preventDefault();
wake();
goal = clamp(goal, 0, MAX_X);
if (still) {
x = goal;
say(TXT_STOP);
draw();
return;
}
// 키도 관성으로 — 목표에서 정확히 멈추는 처음 속도를 등비급수로 거꾸로 푼다
v = speedFor(goal - x, FRICTION);
moving = true;
say(TXT_GLIDE);
});
if (backBtn) {
backBtn.addEventListener('click', function () {
wake();
if (still) {
x = 0;
say(TXT_STOP);
draw();
return;
}
v = speedFor(-x, FRICTION);
moving = true;
say(TXT_GLIDE);
});
}
say(TXT_GLIDE);
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);
};
})();// HscWheelDeltaInertiaGlideTrack - vanilla 판(01-hsc-wheel-delta-inertia-glide-track) 의 React 포트. 같은 계산을 useEffect 안에서 돌린다.
import { useEffect, useRef } from "react";
import styles from "./HscWheelDeltaInertiaGlideTrack.module.scss";
const cx = (s: string): string => s.split(" ").map((n) => styles[n] ?? n).join(" ");
export default function HscWheelDeltaInertiaGlideTrack() {
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;
// 파스텔 팔레트 — 어두운 무대 위에 밝은 카드를 얹어 명도 차로 읽힌다
const BG: RGB = [29, 26, 44];
const PAPER: RGB = [255, 248, 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; }
}
// 휠 한 번의 이동량을 px 로 — 줄 단위(deltaMode 1)·쪽 단위(deltaMode 2) 장치도 같은 눈금으로 맞춘다.
// 가로·세로 중 큰 쪽을 쓴다: 트랙패드의 가로 쓸기와 마우스 휠의 세로 굴림이 같은 방향으로 들어온다
function wheelPx(ev: WheelEvent): number {
const unit = ev.deltaMode === 1 ? 16 : (ev.deltaMode === 2 ? W : 1);
const d = Math.abs(ev.deltaX) > Math.abs(ev.deltaY) ? ev.deltaX : ev.deltaY;
return d * unit;
}
// 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 {
const dpr = window.devicePixelRatio || 1;
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];
}
function roundRectPath(c: CanvasRenderingContext2D, x: number, y: number, w: number, h: number, r: number): void {
const rr = Math.min(r, w / 2, h / 2);
c.beginPath();
c.moveTo(x + rr, y);
c.lineTo(x + w - rr, y);
c.quadraticCurveTo(x + w, y, x + w, y + rr);
c.lineTo(x + w, y + h - rr);
c.quadraticCurveTo(x + w, y + h, x + w - rr, y + h);
c.lineTo(x + rr, y + h);
c.quadraticCurveTo(x, y + h, x, y + h - rr);
c.lineTo(x, y + rr);
c.quadraticCurveTo(x, y, x + rr, y);
c.closePath();
}
// 카드 한 장 — 사진 대신 계산한 그림 칸(그라디언트 하늘·해·언덕) + 글줄 막대 두 개 + 번호
function drawCard(c: CanvasRenderingContext2D, x: number, y: number, w: number, h: number, i: number, light: number): void {
const t1 = TINTS[i % TINTS.length];
const t2 = TINTS[(i + 2) % TINTS.length];
const k = clamp(light, 0, 1);
roundRectPath(c, x, y, w, h, 10);
c.fillStyle = rgba(mix(BG, PAPER, k), 1);
c.fill();
const ih = h * 0.58;
const g = c.createLinearGradient(x, y, x + w, y + ih);
g.addColorStop(0, rgba(mix(BG, t1, k), 1));
g.addColorStop(1, rgba(mix(BG, t2, k * 0.92), 1));
c.save();
roundRectPath(c, x + 6, y + 6, w - 12, ih - 6, 7);
c.fillStyle = g;
c.fill();
c.clip();
c.fillStyle = rgba(mix(BG, PAPER, k * 0.9), 0.9);
c.beginPath();
c.arc(x + w * 0.7, y + ih * 0.36, Math.min(w, ih) * 0.13, 0, Math.PI * 2);
c.fill();
c.fillStyle = rgba(mix(BG, INK, k), 0.55);
c.beginPath();
c.moveTo(x, y + ih);
c.lineTo(x + w * 0.32, y + ih * 0.55);
c.lineTo(x + w * 0.55, y + ih * 0.8);
c.lineTo(x + w * 0.78, y + ih * 0.62);
c.lineTo(x + w, y + ih);
c.closePath();
c.fill();
c.restore();
c.fillStyle = rgba(mix(BG, INK, k), 0.75);
c.fillRect(x + 10, y + ih + 12, w * 0.62, 6);
c.fillStyle = rgba(mix(BG, INK, k), 0.4);
c.fillRect(x + 10, y + ih + 24, w * 0.44, 5);
c.fillStyle = rgba(mix(BG, INK, k), 0.9);
c.font = '700 13px sans-serif';
c.textAlign = 'right';
c.textBaseline = 'alphabetic';
c.fillText(String(i + 1).padStart(2, '0'), x + w - 9, y + h - 10);
}
const CARD_N = 12;
const CARD_W = 118;
const CARD_H = 156;
const GAP = 14;
const PITCH = CARD_W + GAP;
const PAD = 24;
const TRACK_TOP = 58;
const MAX_X = PAD * 2 + CARD_N * PITCH - GAP - W;
const WHEEL_GAIN = 0.12;
const FRICTION = 0.92;
const EDGE_K = 0.16;
const EDGE_DAMP = 0.6;
const RUBBER_PX = 90;
const STOP_V = 0.05;
const DEMO_LOOP = 4200;
const TXT_GLIDE = '휠 관성으로 미끄러지는 중';
const TXT_EDGE = '끝에서 고무줄처럼 되돌아온다';
const TXT_STOP = '멈춤';
const backBtn = root.querySelector('[data-role="btn"]') as HTMLButtonElement | null;
let x = 0;
let v = 0;
let moving = false;
let edgeSaid = false;
let dragId = -1;
let dragX = 0;
let dragT = 0;
let dragV = 0;
// 트랙 끝 밖으로 나간 거리(안쪽이면 0)
function overshoot(p: number): number { return p < 0 ? p : (p > MAX_X ? p - MAX_X : 0); }
// 끝 밖으로 미는 입력은 나간 거리만큼 줄인다 — 고무줄처럼 버틴다
function rubber(d: number): number {
const out = (x <= 0 && d < 0) || (x >= MAX_X && d > 0);
return out ? d / (1 + Math.abs(overshoot(x)) / RUBBER_PX) : d;
}
function push(d: number): void {
v += rubber(d) * WHEEL_GAIN;
moving = true;
say(TXT_GLIDE);
}
// 지금 속도로 놓아두면 얼마나 더 가나 — 스텝마다 FRICTION 을 곱하므로 등비급수 v·f/(1−f)
function glideDistance(v0: number, f: number): number { return v0 * f / (1 - f); }
// 거꾸로, distance 만큼 가서 멈추려면 처음 속도가 얼마여야 하나
function speedFor(distance: number, f: number): number { return distance * (1 - f) / f; }
function canMove(d: number): boolean { return d > 0 ? x < MAX_X - 0.5 : x > 0.5; }
function step(): void {
if (dragId >= 0) { return; }
x += v;
const o = overshoot(x);
if (o !== 0) {
v = (v - o * EDGE_K) * EDGE_DAMP;
if (!edgeSaid) { edgeSaid = true; say(TXT_EDGE); }
} else {
v *= FRICTION;
edgeSaid = false;
}
if (moving && Math.abs(v) < STOP_V && Math.abs(o) < 0.5) {
x = clamp(x, 0, MAX_X);
v = 0;
moving = false;
say(TXT_STOP);
}
}
function settle(): void {
x = 0;
v = 0;
say(TXT_STOP);
}
function demoTick(t: number): void {
for (let k = 0; k < 3; k += 1) { if (crossed(t, 200 + k * 40, DEMO_LOOP)) { push(100); } }
for (let k = 0; k < 5; k += 1) { if (crossed(t, 1250 + k * 40, DEMO_LOOP)) { push(-100); } }
}
function draw(): void {
ctx.fillStyle = rgba(BG, 1);
ctx.fillRect(0, 0, W, H);
// 바닥 레일
ctx.fillStyle = rgba(mix(BG, LILAC, 0.16), 1);
ctx.fillRect(0, TRACK_TOP + CARD_H + 14, W, 3);
for (let i = 0; i < CARD_N; i += 1) {
const cx = PAD + i * PITCH - x;
if (cx > W || cx + CARD_W < 0) { continue; }
drawCard(ctx, cx, TRACK_TOP, CARD_W, CARD_H, i, 1);
}
// 위쪽 진행 막대 — 끝 밖으로 나가면 막대가 그만큼 짧아진다
const trackW = W - 48;
const thumbW = trackW * (W / (MAX_X + W));
const o = overshoot(x);
const squash = Math.abs(o) * 0.6;
const left = 24 + (clamp(x, 0, MAX_X) / MAX_X) * (trackW - thumbW) + (o > 0 ? squash : 0);
ctx.fillStyle = rgba(mix(BG, PAPER, 0.14), 1);
ctx.fillRect(24, 26, trackW, 6);
ctx.fillStyle = rgba(SKY, 1);
ctx.fillRect(left, 26, Math.max(10, thumbW - squash), 6);
// 속도 눈금 — 마찰로 줄어드는 모습이 그대로 보인다
const speedW = clamp(Math.abs(v) * 2.4, 0, trackW);
ctx.fillStyle = rgba(PINK, 0.9);
ctx.fillRect(W / 2 - speedW / 2, 38, speedW, 3);
}
function onWheel(ev: WheelEvent): void {
const d = wheelPx(ev);
// 끝에 닿았으면 가로채지 않는다 — 페이지가 계속 스크롤된다
if (d === 0 || !canMove(d)) { return; }
ev.preventDefault();
wake();
if (still) {
x = clamp(x + d, 0, MAX_X);
say(TXT_STOP);
draw();
return;
}
push(d);
}
cv.addEventListener('wheel', onWheel, { passive: false });
cv.addEventListener('pointerdown', function (ev: PointerEvent): void {
wake();
dragId = ev.pointerId;
cv.setPointerCapture(ev.pointerId);
dragX = toScene(ev)[0];
dragT = ev.timeStamp;
dragV = 0;
v = 0;
});
cv.addEventListener('pointermove', function (ev: PointerEvent): void {
if (ev.pointerId !== dragId) { return; }
const sx = toScene(ev)[0];
const dx = sx - dragX;
const steps = Math.max(1, (ev.timeStamp - dragT) / FIXED_DT);
dragX = sx;
dragT = ev.timeStamp;
const d = rubber(-dx);
x = still ? clamp(x + d, 0, MAX_X) : x + d;
dragV = lerp(dragV, d / steps, 0.5);
if (still) { draw(); }
});
function endDrag(ev: PointerEvent): void {
if (ev.pointerId !== dragId) { return; }
dragId = -1;
if (still) { return; }
v = clamp(dragV, -60, 60);
moving = true;
say(TXT_GLIDE);
}
cv.addEventListener('pointerup', endDrag);
cv.addEventListener('pointercancel', endDrag);
cv.addEventListener('keydown', function (ev: KeyboardEvent): void {
let goal = NaN;
if (ev.key === 'ArrowRight') { goal = x + PITCH; }
else if (ev.key === 'ArrowLeft') { goal = x - PITCH; }
else if (ev.key === 'Home') { goal = 0; }
else if (ev.key === 'End') { goal = MAX_X; }
if (Number.isNaN(goal) || !canMove(goal - x)) { return; }
ev.preventDefault();
wake();
goal = clamp(goal, 0, MAX_X);
if (still) { x = goal; say(TXT_STOP); draw(); return; }
// 키도 관성으로 — 목표에서 정확히 멈추는 처음 속도를 등비급수로 거꾸로 푼다
v = speedFor(goal - x, FRICTION);
moving = true;
say(TXT_GLIDE);
});
if (backBtn) {
backBtn.addEventListener('click', function (): void {
wake();
if (still) { x = 0; say(TXT_STOP); draw(); return; }
v = speedFor(-x, FRICTION);
moving = true;
say(TXT_GLIDE);
});
}
say(TXT_GLIDE);
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="휠이나 끌기로 카드 트랙을 옆으로 밀면 마찰로 서서히 멈추고 양 끝에서 고무줄처럼 되돌아오는 장면"></canvas>
<p className={cx("hs__status")} data-role="status" aria-live="off">휠 관성으로 미끄러지는 중</p>
<div className={cx("hs__tools")}>
<button className={cx("hs__btn")} data-role="btn" type="button">처음으로</button>
</div>
</div>
);
}01 A Card Track Where Vertical Wheel Input Becomes Sideways Motion and Friction Slows It After Input Stops — Measured area 41.419% · moving frames 16/23Original by GODRICH · SCSS and React ship in the zip · Horizontal Scroll Animation CSS: 9 Inertia Scenes
The post this demo lives in
Horizontal Scroll Animation CSS: 9 Inertia ScenesHorizontal scroll animation css is more than turning wheel input sideways — scene 01 glides it on inertia, 06 projects c See all demos in this post
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