09A Desk Hero Where the Sun Sets and a Lamp Turns On
The projection, blur and sun-height calculations meet in one scene: the sun shadow stretches and fades, then a lamp shadow takes over.
Best forA landing hero background
DUSK_FRAMESLAMP_HEIGHTSUN_HEIGHT_DUSK
<main class="stage">
<div class="sc is-demo" id="scRoot">
<canvas class="sc__canvas" id="scCanvas" width="480" height="300" tabindex="0" aria-label="The projection, blur and sun-height calculations meet in one scene: the sun shadow stretches and fades, then a lamp shadow takes over."></canvas>
<p class="sc__status" id="scStatus" aria-live="polite">Demo running</p>
<button class="sc__btn" id="scBtn" type="button">Pause</button>
<p class="sc__caption">The projection, blur and sun-height calculations meet in one scene: the sun shadow stretches and fades, then a lamp shadow takes over.</p>
</div>
</main>@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-ink);
.sc {
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;
}
.sc__canvas {
display: block;
width: 100%;
height: 100%;
touch-action: none;
}
.sc__canvas:focus-visible {
outline: 2px solid rgba(255, 255, 255, .85);
outline-offset: -6px;
}
.sc__status {
position: absolute;
left: $sp-3;
top: $sp-3;
max-width: 62%;
margin: 0;
padding: $sp-1 $sp-3;
border-radius: $r-pill;
background: rgba(255, 255, 255, .85);
color: $subject-ink;
font-weight: 500;
font-size: 11px;
line-height: 1.4;
pointer-events: none;
}
.sc__btn {
position: absolute;
right: $sp-3;
bottom: $sp-3;
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;
}
.sc__btn:focus-visible {
outline: 2px solid #ffffff;
outline-offset: 2px;
}
.sc__caption {
position: absolute;
left: $sp-3;
bottom: $sp-3;
max-width: 68%;
margin: 0;
padding: $sp-1 $sp-3;
border-radius: $r-pill;
background: rgba(255, 255, 255, .85);
color: $subject-ink;
font-weight: 500;
font-size: 12px;
line-height: 1.4;
pointer-events: none;
}
@media (max-width: 340px) {
.sc__caption, .sc__btn { font-size: 10px; padding: $sp-1 $sp-2; }
.sc__status { font-size: 10px; }
}
@media (prefers-reduced-motion: reduce) {
.sc { cursor: default; }
}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);
}
.sc {
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;
}
.sc__canvas {
display: block;
width: 100%;
height: 100%;
touch-action: none;
}
.sc__canvas:focus-visible {
outline: 2px solid rgba(255, 255, 255, 0.85);
outline-offset: -6px;
}
.sc__status {
position: absolute;
left: 12px;
top: 12px;
max-width: 62%;
margin: 0;
padding: 4px 12px;
border-radius: 999px;
background: rgba(255, 255, 255, 0.85);
color: #17141a;
font-weight: 500;
font-size: 11px;
line-height: 1.4;
pointer-events: none;
}
.sc__btn {
position: absolute;
right: 12px;
bottom: 12px;
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;
}
.sc__btn:focus-visible {
outline: 2px solid #ffffff;
outline-offset: 2px;
}
.sc__caption {
position: absolute;
left: 12px;
bottom: 12px;
max-width: 68%;
margin: 0;
padding: 4px 12px;
border-radius: 999px;
background: rgba(255, 255, 255, 0.85);
color: #17141a;
font-weight: 500;
font-size: 12px;
line-height: 1.4;
pointer-events: none;
}
@media (max-width: 340px) {
.sc__caption, .sc__btn {
font-size: 10px;
padding: 4px 8px;
}
.sc__status {
font-size: 10px;
}
}
@media (prefers-reduced-motion: reduce) {
.sc {
cursor: default;
}
}(function () {
const W = 480;
const H = 300;
const PI2 = Math.PI * 2;
const FIXED_DT = 16;
const REDUCE_STEP_MS = 900;
const REDUCE_START_MS = 1000;
const PERIOD_MS = 4000;
const KEY_STEP = 12;
const FONT = '-apple-system, "Segoe UI", "Noto Sans KR", sans-serif';
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]) + ',' + a.toFixed(3) + ')';
}
// 시드 고정 난수 — 같은 시드면 언제나 같은 수열
function mulberry32(seed) {
let s = seed >>> 0;
return function () {
s = (s + 0x6D2B79F5) >>> 0;
let t = s;
t = Math.imul(t ^ (t >>> 15), t | 1);
t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
};
}
function glow(ctx, x, y, r, c, a) {
const g = ctx.createRadialGradient(x, y, 0, x, y, r);
g.addColorStop(0, rgba(c, a));
g.addColorStop(1, rgba(c, 0));
ctx.fillStyle = g;
ctx.fillRect(x - r, y - r, r * 2, r * 2);
}
function polyPath(ctx, poly) {
ctx.beginPath();
for (let i = 0; i < poly.length; i += 1) {
if (i === 0) {
ctx.moveTo(poly[i][0], poly[i][1]);
}
else {
ctx.lineTo(poly[i][0], poly[i][1]);
}
}
ctx.closePath();
}
// 광원 (lx, ly, lh) 에서 점 (x, y, h) 를 바닥 높이 0 으로 내리는 투영 — 닮음비 lh / (lh - h)
function castPoint(lx, ly, lh, x, y, h) {
const k = lh / Math.max(lh - h, 8);
return [lx + (x - lx) * k, ly + (y - ly) * k];
}
// 볼록 껍질 (단조 체인) — 바닥 꼭짓점과 투영된 윗 꼭짓점을 한 덩어리 그림자로 묶는다
function hull(src) {
const p = src.slice().sort(function (a, b) { return a[0] - b[0] || a[1] - b[1]; });
function cross(o, a, b) { return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]); }
const lo = [];
for (let i = 0; i < p.length; i += 1) {
while (lo.length >= 2 && cross(lo[lo.length - 2], lo[lo.length - 1], p[i]) <= 0) {
lo.pop();
}
lo.push(p[i]);
}
const up = [];
for (let i = p.length - 1; i >= 0; i -= 1) {
while (up.length >= 2 && cross(up[up.length - 2], up[up.length - 1], p[i]) <= 0) {
up.pop();
}
up.push(p[i]);
}
lo.pop();
up.pop();
return lo.concat(up);
}
// 직육면체 한 개의 그림자 다각형 — 바닥 네 꼭짓점과 높이 h 위 네 꼭짓점을 광원에서 투영한다
function boxShadow(lx, ly, lh, x0, y0, x1, y1, h) {
const base = [[x0, y0], [x1, y0], [x1, y1], [x0, y1]];
const pts = base.slice();
for (let i = 0; i < base.length; i += 1) {
pts.push(castPoint(lx, ly, lh, base[i][0], base[i][1], h));
}
return hull(pts);
}
function fillShadow(ctx, poly, ink, alpha) {
polyPath(ctx, poly);
ctx.fillStyle = rgba(ink, alpha);
ctx.fill();
ctx.lineJoin = 'round';
ctx.lineWidth = 7;
ctx.strokeStyle = rgba(ink, alpha * 0.32);
ctx.stroke();
}
// 비스듬히 본 직육면체 — 윗면은 높이의 0.6 만큼 위로 밀고 앞면을 아래에 붙인다
function drawBlock(ctx, x0, y0, x1, y1, h, top, front) {
const vis = h * 0.6;
ctx.fillStyle = rgba(front, 1);
ctx.fillRect(x0, y1 - vis, x1 - x0, vis);
ctx.fillStyle = rgba(top, 1);
ctx.fillRect(x0, y0 - vis, x1 - x0, y1 - y0);
ctx.fillStyle = 'rgba(255,255,255,0.35)';
ctx.fillRect(x0, y0 - vis, x1 - x0, 2);
}
const DUSK_FRAMES = 125;
const LAMP_HEIGHT = 150;
const SUN_HEIGHT_NOON = 420;
const SUN_HEIGHT_DUSK = 70;
const LIGHT_LERP = 0.2;
const DUSK_MS = DUSK_FRAMES * FIXED_DT;
const DESK_DAY = [244, 226, 200];
const DESK_NIGHT = [52, 46, 92];
const INK_RGB = [66, 48, 112];
const SUN_RGB = [255, 206, 120];
const LAMP_RGB = [255, 214, 140];
const LAMP_SPOT = [404, 74];
const SUN_SPOT = [-60, 96];
const ITEMS = [[104, 168, 188, 218, 16], [236, 188, 270, 222, 40], [312, 128, 344, 160, 56]];
const ITEM_TOPS = [[255, 214, 204], [190, 226, 255], [180, 240, 216]];
const ITEM_FRONTS = [[226, 150, 140], [120, 176, 230], [110, 200, 160]];
function makeScene(ctx) {
let px = 0;
const scene = {
path: function (t) {
const c = (t / (DUSK_MS * 2)) % 1;
const tri = c < 0.5 ? c * 2 : 2 - c * 2;
return [W * smooth(tri), 150];
},
pos: function () { return [px, 150]; },
update: function (tx) { px = lerp(px, tx, LIGHT_LERP); },
snap: function (tx) { px = tx; },
draw: function () {
const p = clamp(px / W, 0, 1);
const night = smooth(p);
const lampOn = smooth((p - 0.35) / 0.4);
const sunAlpha = 1 - 0.9 * smooth((p - 0.55) / 0.45);
const desk = [lerp(DESK_DAY[0], DESK_NIGHT[0], night), lerp(DESK_DAY[1], DESK_NIGHT[1], night), lerp(DESK_DAY[2], DESK_NIGHT[2], night)];
ctx.fillStyle = rgba(desk, 1);
ctx.fillRect(0, 0, W, H);
glow(ctx, SUN_SPOT[0] + 20, SUN_SPOT[1], 380, SUN_RGB, 0.7 * sunAlpha);
glow(ctx, LAMP_SPOT[0], LAMP_SPOT[1], 280, LAMP_RGB, 0.9 * lampOn);
const sunH = lerp(SUN_HEIGHT_NOON, SUN_HEIGHT_DUSK, smooth(p));
for (let i = 0; i < ITEMS.length; i += 1) {
const r = ITEMS[i];
fillShadow(ctx, boxShadow(SUN_SPOT[0], SUN_SPOT[1], sunH, r[0], r[1], r[2], r[3], r[4]), INK_RGB, 0.4 * sunAlpha);
fillShadow(ctx, boxShadow(LAMP_SPOT[0], LAMP_SPOT[1], LAMP_HEIGHT, r[0], r[1], r[2], r[3], r[4]), INK_RGB, 0.5 * lampOn);
}
for (let i = 0; i < ITEMS.length; i += 1) {
const r = ITEMS[i];
drawBlock(ctx, r[0], r[1], r[2], r[3], r[4], ITEM_TOPS[i], ITEM_FRONTS[i]);
}
// 램프 머리 — 켜지면 빛이 번진다
ctx.beginPath();
ctx.arc(LAMP_SPOT[0], LAMP_SPOT[1], 15, 0, PI2);
ctx.fillStyle = rgba([lerp(236, 255, lampOn), lerp(214, 244, lampOn), lerp(206, 186, lampOn)], 1);
ctx.fill();
ctx.lineWidth = 3;
ctx.strokeStyle = 'rgba(200,170,120,0.95)';
ctx.stroke();
// 해의 높이를 알려 주는 창 표시
glow(ctx, 20, SUN_SPOT[1], 36, SUN_RGB, 0.9 * sunAlpha);
ctx.fillStyle = rgba(SUN_RGB, Math.max(sunAlpha, 0.15));
ctx.fillRect(0, SUN_SPOT[1] - 22, 8, 44);
}
};
return scene;
}
function main(rootEl, canvas, statusEl, btnEl) {
const ctx0 = canvas.getContext('2d');
if (!ctx0) {
return function () { return; };
}
canvas.width = W;
canvas.height = H;
const scene = makeScene(ctx0);
const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
if (reduce) {
rootEl.classList.remove('is-demo');
}
let paused = false;
let autoplay = !reduce;
let elapsed = reduce ? REDUCE_START_MS : 0;
let rafId = 0;
let lastTs = null;
let accMs = 0;
let tgt = scene.path(elapsed);
const cleaners = [];
function listen(target, type, fn) {
target.addEventListener(type, fn);
cleaners.push(function () { target.removeEventListener(type, fn); });
}
function setMode() {
if (reduce) {
statusEl.textContent = 'Stepping one scene at a time';
btnEl.textContent = 'Next scene';
return;
}
statusEl.textContent = !autoplay ? 'Manual control' : (paused ? 'Paused' : 'Demo running');
btnEl.textContent = (autoplay && !paused) ? 'Pause' : 'Play';
}
function toLocal(e) {
const r = canvas.getBoundingClientRect();
return [clamp((e.clientX - r.left) * W / r.width, 0, W), clamp((e.clientY - r.top) * H / r.height, 0, H)];
}
function takeOver() {
if (reduce || !autoplay) {
return;
}
autoplay = false;
paused = false;
rootEl.classList.remove('is-demo');
const p = scene.pos();
tgt = [p[0], p[1]];
setMode();
}
function afterInput() {
if (reduce) {
scene.snap(tgt[0], tgt[1]);
scene.draw(elapsed);
}
}
function onButton() {
if (reduce) {
elapsed += REDUCE_STEP_MS;
tgt = scene.path(elapsed);
scene.snap(tgt[0], tgt[1]);
scene.draw(elapsed);
return;
}
if (autoplay && !paused) {
paused = true;
}
else {
paused = false;
autoplay = true;
rootEl.classList.add('is-demo');
}
setMode();
}
function tick(ts) {
if (lastTs === null) {
lastTs = ts;
}
const frameDt = Math.min(ts - lastTs, 160);
lastTs = ts;
if (!paused) {
accMs += frameDt;
while (accMs >= FIXED_DT) {
elapsed += FIXED_DT;
accMs -= FIXED_DT;
if (autoplay) {
tgt = scene.path(elapsed);
}
scene.update(tgt[0], tgt[1]);
}
scene.draw(elapsed);
}
rafId = requestAnimationFrame(tick);
}
listen(btnEl, 'click', function () { onButton(); });
listen(canvas, 'pointerdown', function (e) {
takeOver();
tgt = toLocal(e);
afterInput();
});
listen(canvas, 'pointermove', function (e) {
if (autoplay && !reduce) {
return;
}
tgt = toLocal(e);
afterInput();
});
listen(canvas, 'keydown', function (e) {
const k = e.key;
if (k === 'Enter' || k === ' ') {
e.preventDefault();
onButton();
return;
}
let dx = 0;
let dy = 0;
if (k === 'ArrowLeft') {
dx = -KEY_STEP;
}
else if (k === 'ArrowRight') {
dx = KEY_STEP;
}
else if (k === 'ArrowUp') {
dy = -KEY_STEP;
}
else if (k === 'ArrowDown') {
dy = KEY_STEP;
}
else {
return;
}
e.preventDefault();
takeOver();
tgt = [clamp(tgt[0] + dx, 0, W), clamp(tgt[1] + dy, 0, H)];
afterInput();
});
if (reduce) {
scene.snap(tgt[0], tgt[1]);
scene.draw(elapsed);
setMode();
}
else {
scene.draw(elapsed);
setMode();
rafId = requestAnimationFrame(tick);
}
function destroy() {
cancelAnimationFrame(rafId);
for (let i = 0; i < cleaners.length; i += 1) {
cleaners[i]();
}
}
return destroy;
}
main(document.getElementById('scRoot'), document.getElementById('scCanvas'), document.getElementById('scStatus'), document.getElementById('scBtn'));
})();import { useEffect, useRef } from "react";
import styles from "./ShcastDeskLampDuskHeroScene.module.scss";
const W = 480;
const H = 300;
const PI2 = Math.PI * 2;
const FIXED_DT = 16;
const REDUCE_STEP_MS = 900;
const REDUCE_START_MS = 1000;
const PERIOD_MS = 4000;
const KEY_STEP = 12;
const FONT = '-apple-system, "Segoe UI", "Noto Sans KR", sans-serif';
type Pt = [number, number];
interface Scene {
path(t: number): Pt;
pos(): Pt;
update(tx: number, ty: number): void;
snap(tx: number, ty: number): void;
draw(t: number): void;
}
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: number[], a: number): string {
return 'rgba(' + Math.round(c[0]) + ',' + Math.round(c[1]) + ',' + Math.round(c[2]) + ',' + a.toFixed(3) + ')';
}
// 시드 고정 난수 — 같은 시드면 언제나 같은 수열
function mulberry32(seed: number): () => number {
let s = seed >>> 0;
return function (): number {
s = (s + 0x6D2B79F5) >>> 0;
let t = s;
t = Math.imul(t ^ (t >>> 15), t | 1);
t ^= t + Math.imul(t ^ (t >>> 7), t | 61);
return ((t ^ (t >>> 14)) >>> 0) / 4294967296;
};
}
function glow(ctx: CanvasRenderingContext2D, x: number, y: number, r: number, c: number[], a: number): void {
const g = ctx.createRadialGradient(x, y, 0, x, y, r);
g.addColorStop(0, rgba(c, a));
g.addColorStop(1, rgba(c, 0));
ctx.fillStyle = g;
ctx.fillRect(x - r, y - r, r * 2, r * 2);
}
function polyPath(ctx: CanvasRenderingContext2D, poly: Pt[]): void {
ctx.beginPath();
for (let i = 0; i < poly.length; i += 1) {
if (i === 0) { ctx.moveTo(poly[i][0], poly[i][1]); } else { ctx.lineTo(poly[i][0], poly[i][1]); }
}
ctx.closePath();
}
// 광원 (lx, ly, lh) 에서 점 (x, y, h) 를 바닥 높이 0 으로 내리는 투영 — 닮음비 lh / (lh - h)
function castPoint(lx: number, ly: number, lh: number, x: number, y: number, h: number): Pt {
const k = lh / Math.max(lh - h, 8);
return [lx + (x - lx) * k, ly + (y - ly) * k];
}
// 볼록 껍질 (단조 체인) — 바닥 꼭짓점과 투영된 윗 꼭짓점을 한 덩어리 그림자로 묶는다
function hull(src: Pt[]): Pt[] {
const p = src.slice().sort(function (a: Pt, b: Pt): number { return a[0] - b[0] || a[1] - b[1]; });
function cross(o: Pt, a: Pt, b: Pt): number { return (a[0] - o[0]) * (b[1] - o[1]) - (a[1] - o[1]) * (b[0] - o[0]); }
const lo: Pt[] = [];
for (let i = 0; i < p.length; i += 1) {
while (lo.length >= 2 && cross(lo[lo.length - 2], lo[lo.length - 1], p[i]) <= 0) { lo.pop(); }
lo.push(p[i]);
}
const up: Pt[] = [];
for (let i = p.length - 1; i >= 0; i -= 1) {
while (up.length >= 2 && cross(up[up.length - 2], up[up.length - 1], p[i]) <= 0) { up.pop(); }
up.push(p[i]);
}
lo.pop();
up.pop();
return lo.concat(up);
}
// 직육면체 한 개의 그림자 다각형 — 바닥 네 꼭짓점과 높이 h 위 네 꼭짓점을 광원에서 투영한다
function boxShadow(lx: number, ly: number, lh: number, x0: number, y0: number, x1: number, y1: number, h: number): Pt[] {
const base: Pt[] = [[x0, y0], [x1, y0], [x1, y1], [x0, y1]];
const pts: Pt[] = base.slice();
for (let i = 0; i < base.length; i += 1) { pts.push(castPoint(lx, ly, lh, base[i][0], base[i][1], h)); }
return hull(pts);
}
function fillShadow(ctx: CanvasRenderingContext2D, poly: Pt[], ink: number[], alpha: number): void {
polyPath(ctx, poly);
ctx.fillStyle = rgba(ink, alpha);
ctx.fill();
ctx.lineJoin = 'round';
ctx.lineWidth = 7;
ctx.strokeStyle = rgba(ink, alpha * 0.32);
ctx.stroke();
}
// 비스듬히 본 직육면체 — 윗면은 높이의 0.6 만큼 위로 밀고 앞면을 아래에 붙인다
function drawBlock(ctx: CanvasRenderingContext2D, x0: number, y0: number, x1: number, y1: number, h: number, top: number[], front: number[]): void {
const vis = h * 0.6;
ctx.fillStyle = rgba(front, 1);
ctx.fillRect(x0, y1 - vis, x1 - x0, vis);
ctx.fillStyle = rgba(top, 1);
ctx.fillRect(x0, y0 - vis, x1 - x0, y1 - y0);
ctx.fillStyle = 'rgba(255,255,255,0.35)';
ctx.fillRect(x0, y0 - vis, x1 - x0, 2);
}
const DUSK_FRAMES = 125;
const LAMP_HEIGHT = 150;
const SUN_HEIGHT_NOON = 420;
const SUN_HEIGHT_DUSK = 70;
const LIGHT_LERP = 0.2;
const DUSK_MS = DUSK_FRAMES * FIXED_DT;
const DESK_DAY = [244, 226, 200];
const DESK_NIGHT = [52, 46, 92];
const INK_RGB = [66, 48, 112];
const SUN_RGB = [255, 206, 120];
const LAMP_RGB = [255, 214, 140];
const LAMP_SPOT = [404, 74];
const SUN_SPOT = [-60, 96];
const ITEMS = [[104, 168, 188, 218, 16], [236, 188, 270, 222, 40], [312, 128, 344, 160, 56]];
const ITEM_TOPS = [[255, 214, 204], [190, 226, 255], [180, 240, 216]];
const ITEM_FRONTS = [[226, 150, 140], [120, 176, 230], [110, 200, 160]];
function makeScene(ctx: CanvasRenderingContext2D): Scene {
let px = 0;
const scene: Scene = {
path: function (t: number): Pt {
const c = (t / (DUSK_MS * 2)) % 1;
const tri = c < 0.5 ? c * 2 : 2 - c * 2;
return [W * smooth(tri), 150];
},
pos: function (): Pt { return [px, 150]; },
update: function (tx: number): void { px = lerp(px, tx, LIGHT_LERP); },
snap: function (tx: number): void { px = tx; },
draw: function (): void {
const p = clamp(px / W, 0, 1);
const night = smooth(p);
const lampOn = smooth((p - 0.35) / 0.4);
const sunAlpha = 1 - 0.9 * smooth((p - 0.55) / 0.45);
const desk = [lerp(DESK_DAY[0], DESK_NIGHT[0], night), lerp(DESK_DAY[1], DESK_NIGHT[1], night), lerp(DESK_DAY[2], DESK_NIGHT[2], night)];
ctx.fillStyle = rgba(desk, 1);
ctx.fillRect(0, 0, W, H);
glow(ctx, SUN_SPOT[0] + 20, SUN_SPOT[1], 380, SUN_RGB, 0.7 * sunAlpha);
glow(ctx, LAMP_SPOT[0], LAMP_SPOT[1], 280, LAMP_RGB, 0.9 * lampOn);
const sunH = lerp(SUN_HEIGHT_NOON, SUN_HEIGHT_DUSK, smooth(p));
for (let i = 0; i < ITEMS.length; i += 1) {
const r = ITEMS[i];
fillShadow(ctx, boxShadow(SUN_SPOT[0], SUN_SPOT[1], sunH, r[0], r[1], r[2], r[3], r[4]), INK_RGB, 0.4 * sunAlpha);
fillShadow(ctx, boxShadow(LAMP_SPOT[0], LAMP_SPOT[1], LAMP_HEIGHT, r[0], r[1], r[2], r[3], r[4]), INK_RGB, 0.5 * lampOn);
}
for (let i = 0; i < ITEMS.length; i += 1) {
const r = ITEMS[i];
drawBlock(ctx, r[0], r[1], r[2], r[3], r[4], ITEM_TOPS[i], ITEM_FRONTS[i]);
}
// 램프 머리 — 켜지면 빛이 번진다
ctx.beginPath();
ctx.arc(LAMP_SPOT[0], LAMP_SPOT[1], 15, 0, PI2);
ctx.fillStyle = rgba([lerp(236, 255, lampOn), lerp(214, 244, lampOn), lerp(206, 186, lampOn)], 1);
ctx.fill();
ctx.lineWidth = 3;
ctx.strokeStyle = 'rgba(200,170,120,0.95)';
ctx.stroke();
// 해의 높이를 알려 주는 창 표시
glow(ctx, 20, SUN_SPOT[1], 36, SUN_RGB, 0.9 * sunAlpha);
ctx.fillStyle = rgba(SUN_RGB, Math.max(sunAlpha, 0.15));
ctx.fillRect(0, SUN_SPOT[1] - 22, 8, 44);
}
};
return scene;
}
function main(rootEl: HTMLElement, canvas: HTMLCanvasElement, statusEl: HTMLElement, btnEl: HTMLButtonElement): () => void {
const ctx0 = canvas.getContext('2d');
if (!ctx0) { return function (): void { return; }; }
canvas.width = W;
canvas.height = H;
const scene: Scene = makeScene(ctx0);
const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
if (reduce) { rootEl.classList.remove('is-demo'); }
let paused = false;
let autoplay = !reduce;
let elapsed = reduce ? REDUCE_START_MS : 0;
let rafId = 0;
let lastTs: number | null = null;
let accMs = 0;
let tgt: Pt = scene.path(elapsed);
const cleaners: Array<() => void> = [];
function listen(target: EventTarget, type: string, fn: (e: Event) => void): void {
target.addEventListener(type, fn);
cleaners.push(function (): void { target.removeEventListener(type, fn); });
}
function setMode(): void {
if (reduce) {
statusEl.textContent = '한 장면씩 넘기는 중';
btnEl.textContent = '다음 장면';
return;
}
statusEl.textContent = !autoplay ? '직접 조작 중' : (paused ? '일시정지됨' : '시연 중');
btnEl.textContent = (autoplay && !paused) ? '멈춤' : '재생';
}
function toLocal(e: PointerEvent): Pt {
const r = canvas.getBoundingClientRect();
return [clamp((e.clientX - r.left) * W / r.width, 0, W), clamp((e.clientY - r.top) * H / r.height, 0, H)];
}
function takeOver(): void {
if (reduce || !autoplay) { return; }
autoplay = false;
paused = false;
rootEl.classList.remove('is-demo');
const p = scene.pos();
tgt = [p[0], p[1]];
setMode();
}
function afterInput(): void {
if (reduce) {
scene.snap(tgt[0], tgt[1]);
scene.draw(elapsed);
}
}
function onButton(): void {
if (reduce) {
elapsed += REDUCE_STEP_MS;
tgt = scene.path(elapsed);
scene.snap(tgt[0], tgt[1]);
scene.draw(elapsed);
return;
}
if (autoplay && !paused) {
paused = true;
} else {
paused = false;
autoplay = true;
rootEl.classList.add('is-demo');
}
setMode();
}
function tick(ts: number): void {
if (lastTs === null) { lastTs = ts; }
const frameDt = Math.min(ts - lastTs, 160);
lastTs = ts;
if (!paused) {
accMs += frameDt;
while (accMs >= FIXED_DT) {
elapsed += FIXED_DT;
accMs -= FIXED_DT;
if (autoplay) { tgt = scene.path(elapsed); }
scene.update(tgt[0], tgt[1]);
}
scene.draw(elapsed);
}
rafId = requestAnimationFrame(tick);
}
listen(btnEl, 'click', function (): void { onButton(); });
listen(canvas, 'pointerdown', function (e: Event): void {
takeOver();
tgt = toLocal(e as PointerEvent);
afterInput();
});
listen(canvas, 'pointermove', function (e: Event): void {
if (autoplay && !reduce) { return; }
tgt = toLocal(e as PointerEvent);
afterInput();
});
listen(canvas, 'keydown', function (e: Event): void {
const k = (e as KeyboardEvent).key;
if (k === 'Enter' || k === ' ') {
e.preventDefault();
onButton();
return;
}
let dx = 0;
let dy = 0;
if (k === 'ArrowLeft') { dx = -KEY_STEP; } else if (k === 'ArrowRight') { dx = KEY_STEP; }
else if (k === 'ArrowUp') { dy = -KEY_STEP; } else if (k === 'ArrowDown') { dy = KEY_STEP; }
else { return; }
e.preventDefault();
takeOver();
tgt = [clamp(tgt[0] + dx, 0, W), clamp(tgt[1] + dy, 0, H)];
afterInput();
});
if (reduce) {
scene.snap(tgt[0], tgt[1]);
scene.draw(elapsed);
setMode();
} else {
scene.draw(elapsed);
setMode();
rafId = requestAnimationFrame(tick);
}
function destroy(): void {
cancelAnimationFrame(rafId);
for (let i = 0; i < cleaners.length; i += 1) { cleaners[i](); }
}
return destroy;
}
export default function ShcastDeskLampDuskHeroScene() {
const rootRef = useRef<HTMLDivElement | null>(null);
const canvasRef = useRef<HTMLCanvasElement | null>(null);
const statusRef = useRef<HTMLParagraphElement | null>(null);
const btnRef = useRef<HTMLButtonElement | null>(null);
useEffect(() => {
const root = rootRef.current;
const canvas = canvasRef.current;
const statusEl = statusRef.current;
const btnEl = btnRef.current;
if (!root || !canvas || !statusEl || !btnEl) return;
return main(root, canvas, statusEl, btnEl);
}, []);
return (
<main className={styles.stage}>
<div className={`${styles.sc} is-demo`} ref={rootRef}>
<canvas className={styles.sc__canvas} ref={canvasRef} width={480} height={300} tabIndex={0} aria-label="앞의 투영·흐림·해 높이 계산을 한 장면에 모아, 해 그림자가 길어지다 사라지면 램프 그림자가 이어받는다." />
<p className={styles.sc__status} ref={statusRef} aria-live="polite">시연 중</p>
<button className={styles.sc__btn} ref={btnRef} type="button">멈춤</button>
<p className={styles.sc__caption}>앞의 투영·흐림·해 높이 계산을 한 장면에 모아, 해 그림자가 길어지다 사라지면 램프 그림자가 이어받는다.</p>
</div>
</main>
);
}09 A Desk Hero Where the Sun Sets and a Lamp Turns On — Measured area 70.11% · moving frames 18/23Original by GODRICH · SCSS and React ship in the zip · CSS Shadow Effects: 9 Demos That Compute the Cast
The post this demo lives in
CSS Shadow Effects: 9 Demos That Compute the CastWith css shadow effects from one box-shadow line, the shadow stays put as the light circles, light leaks behind walls an See all demos in this post
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