09A Waveform Where Live Recording Appends on the Right and Auto Gain Lifts Quiet Sounds
Each time a new slice arrives one column is appended on the right and the rest shift left, and the gain follows a slowly decaying peak tracker so a whisper and a shout read at similar heights.
Best forVoice-memo recording screens and meeting-recording tools
GAIN_TARGETGAIN_RISEGAIN_FALLSCROLL_PX
<main class="stage">
<div class="wf is-demo" id="wfRoot">
<canvas class="wf__canvas" data-role="canvas" width="480" height="300" tabindex="0" aria-label="A Waveform Where Live Recording Appends on the Right and Auto Gain Lifts Quiet Sounds"></canvas>
<p class="wf__status" data-role="status" aria-live="polite">Auto gain</p>
<button class="wf__btn" data-role="btn" type="button">Pause</button>
<p class="wf__caption">A Waveform Where Live Recording Appends on the Right and Auto Gain Lifts Quiet Sounds</p>
</div>
</main>@use "../../../../site/static/demo-tokens" as *;
@include stage($stage-ink);
.wf {
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;
}
.wf__canvas {
display: block;
width: 100%;
height: 100%;
touch-action: manipulation;
}
.wf__canvas:focus-visible {
outline: 2px solid rgba(255, 255, 255, .85);
outline-offset: -6px;
}
.wf__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;
}
.wf__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;
}
.wf__btn:focus-visible {
outline: 2px solid #ffffff;
outline-offset: 2px;
}
.wf__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) {
.wf__caption, .wf__btn { font-size: 10px; padding: $sp-1 $sp-2; }
.wf__status { font-size: 10px; }
}
@media (prefers-reduced-motion: reduce) {
.wf { 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);
}
.wf {
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;
}
.wf__canvas {
display: block;
width: 100%;
height: 100%;
touch-action: manipulation;
}
.wf__canvas:focus-visible {
outline: 2px solid rgba(255, 255, 255, 0.85);
outline-offset: -6px;
}
.wf__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;
}
.wf__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;
}
.wf__btn:focus-visible {
outline: 2px solid #ffffff;
outline-offset: 2px;
}
.wf__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) {
.wf__caption, .wf__btn {
font-size: 10px;
padding: 4px 8px;
}
.wf__status {
font-size: 10px;
}
}
@media (prefers-reduced-motion: reduce) {
.wf {
cursor: default;
}
}(function () {
const W = 480;
const H = 300;
const PI2 = Math.PI * 2;
const FIXED_DT = 16;
const IDLE_STEPS = 220;
const REDUCE_STEP_MS = 900;
const REDUCE_WARM_STEPS = 40;
const BTN_PAUSE = 'Pause';
const BTN_PLAY = 'Play';
const BTN_NEXT = 'Next moment';
// 파스텔 팔레트와 어두운 바탕 두 끝 색
const PINK = [255, 170, 196];
const MINT = [150, 226, 196];
const LILAC = [196, 176, 255];
const SKY_BLUE = [150, 214, 255];
const BUTTER = [255, 230, 150];
const CREAM = [255, 247, 230];
const INK = [23, 20, 26];
const BG_TOP = [24, 21, 40];
const BG_BOT = [48, 42, 78];
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 mix(a, b, k) { return [lerp(a[0], b[0], k), lerp(a[1], b[1], k), lerp(a[2], b[2], k)]; }
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 (선형 합동 방식)
function lcg(seed) {
let s = seed >>> 0;
return function () {
s = (Math.imul(s, 1664525) + 1013904223) >>> 0;
return s / 4294967296;
};
}
// 정수 하나와 시드로 0 이상 1 미만의 값을 만드는 해시 (같은 입력은 늘 같은 값)
function hash1(i, seed) {
let h = (Math.imul(i | 0, 374761393) + Math.imul(seed | 0, 668265263)) | 0;
h = Math.imul(h ^ (h >>> 13), 1274126177);
h ^= h >>> 16;
return (h >>> 0) / 4294967296;
}
// 사인 두 개를 음절마다 갈아 끼우고 엔벨로프를 씌운 합성 신호 (소리는 재생하지 않고 수치만 만든다)
function synth(n, seed) {
const rnd = lcg(seed);
const out = new Float32Array(n);
let i = 0;
let p1 = 0;
let p2 = 0;
let peak = 0.0001;
while (i < n) {
const len = 1800 + Math.floor(rnd() * 4200);
const amp = 0.18 + rnd() * 0.82;
const rest = rnd() < 0.18;
const f1 = 0.02 + rnd() * 0.09;
const f2 = f1 * (1.5 + rnd());
const stop = Math.min(n, i + len);
for (let k = i; k < stop; k += 1) {
const x = (k - i) / len;
const env = Math.min(1, x / 0.06) * Math.pow(1 - x, 0.8);
p1 += PI2 * f1;
p2 += PI2 * f2;
const tone = Math.sin(p1) * 0.7 + Math.sin(p2) * 0.3;
const gain = rest ? 0.03 : amp * env;
const v = gain * tone + (rnd() - 0.5) * 0.08 * (rest ? 0.4 : amp);
out[k] = v;
const a = Math.abs(v);
if (a > peak) {
peak = a;
}
}
i = stop;
}
const norm = 0.92 / peak;
for (let k = 0; k < n; k += 1) {
out[k] *= norm;
}
return out;
}
// 표본 구간 [a, b) 의 최솟값과 최댓값 — 결과는 rangeLo, rangeHi 에 둔다
let rangeLo = 0;
let rangeHi = 0;
function scanRange(sig, a, b) {
const from = Math.max(0, Math.floor(a));
const to = Math.min(sig.length, Math.max(from + 1, Math.ceil(b)));
let lo = 1e9;
let hi = -1e9;
for (let i = from; i < to; i += 1) {
const v = sig[i];
if (v < lo) {
lo = v;
}
if (v > hi) {
hi = v;
}
}
if (lo > hi) {
lo = 0;
hi = 0;
}
rangeLo = lo;
rangeHi = hi;
}
function paintBg(ctx, top, bot) {
const g = ctx.createLinearGradient(0, 0, 0, H);
g.addColorStop(0, rgba(top, 1));
g.addColorStop(1, rgba(bot, 1));
ctx.fillStyle = g;
ctx.fillRect(0, 0, W, H);
}
// 가짜 포인터 — 시연 동안 손이 움직이는 것처럼 보이게 그린다
function drawCursor(ctx, x, y, down) {
ctx.save();
ctx.translate(x, y);
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(0, 15);
ctx.lineTo(4, 11.5);
ctx.lineTo(7.5, 18);
ctx.lineTo(10, 16.8);
ctx.lineTo(6.6, 10.4);
ctx.lineTo(11.5, 10.2);
ctx.closePath();
ctx.fillStyle = rgba(CREAM, 1);
ctx.strokeStyle = rgba(INK, 1);
ctx.lineWidth = 1.4;
ctx.fill();
ctx.stroke();
if (down) {
ctx.beginPath();
ctx.arc(0, 0, 9, 0, PI2);
ctx.strokeStyle = rgba(PINK, 0.9);
ctx.lineWidth = 2;
ctx.stroke();
}
ctx.restore();
}
function boot(root, make) {
const canvasEl = root.querySelector('[data-role="canvas"]');
const statusEl = root.querySelector('[data-role="status"]');
const btnEl = root.querySelector('[data-role="btn"]');
if (!(canvasEl instanceof HTMLCanvasElement) || !statusEl || !(btnEl instanceof HTMLButtonElement)) {
return function () { };
}
const ctxOrNull = canvasEl.getContext('2d');
if (!ctxOrNull) {
return function () { };
}
const canvas = canvasEl;
const ctx = ctxOrNull;
const status = statusEl;
const btn = btnEl;
const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
const cleaners = [];
let paused = false;
let idle = IDLE_STEPS + 1;
let clock = 0;
let lastSayAt = -1e9;
let lastText = status.textContent || '';
let scene = null;
let rafId = 0;
let acc = 0;
let lastTs = -1;
function isAuto() { return !reduce && !paused && idle > IDLE_STEPS; }
function sync() {
const on = isAuto();
if (root.classList.contains('is-demo') !== on) {
root.classList.toggle('is-demo', on);
}
}
function fit() {
const r = canvas.getBoundingClientRect();
const dpr = window.devicePixelRatio || 1;
const cw = Math.max(1, Math.round(r.width * dpr));
const ch = Math.max(1, Math.round(r.height * dpr));
canvas.width = cw;
canvas.height = ch;
ctx.setTransform(cw / W, 0, 0, ch / H, 0, 0);
}
const host = {
ctx,
canvas,
root,
reduce,
touch() {
idle = 0;
sync();
},
auto: isAuto,
refresh() {
if (scene) {
scene.draw();
}
},
say(text) {
if (text === lastText) {
return;
}
if (!reduce && clock - lastSayAt < 250) {
return;
}
lastText = text;
lastSayAt = clock;
// 시연이 혼자 돌 때는 읽어 주지 않고, 사람이 만졌을 때만 알린다
status.setAttribute('aria-live', isAuto() ? 'off' : 'polite');
status.textContent = text;
},
local(e) {
const r = canvas.getBoundingClientRect();
return [clamp((e.clientX - r.left) * W / Math.max(1, r.width), 0, W), clamp((e.clientY - r.top) * H / Math.max(1, r.height), 0, H)];
},
listen(target, type, fn, opts) {
target.addEventListener(type, fn, opts);
cleaners.push(function () { target.removeEventListener(type, fn, opts); });
}
};
function advance(ms) {
if (!scene) {
return;
}
const n = Math.max(1, Math.round(ms / FIXED_DT));
for (let i = 0; i < n; i += 1) {
idle += 1;
clock += FIXED_DT;
scene.step();
}
}
function frame(ts) {
if (lastTs < 0) {
lastTs = ts;
}
const dt = Math.min(ts - lastTs, 160);
lastTs = ts;
if (!paused && scene) {
acc += dt;
while (acc >= FIXED_DT) {
idle += 1;
clock += FIXED_DT;
scene.step();
acc -= FIXED_DT;
}
sync();
scene.draw();
}
rafId = requestAnimationFrame(frame);
}
scene = make(host);
btn.textContent = reduce ? BTN_NEXT : BTN_PAUSE;
fit();
if (reduce) {
root.classList.remove('is-demo');
advance(REDUCE_WARM_STEPS * FIXED_DT);
}
scene.draw();
host.listen(btn, 'click', function () {
if (reduce) {
advance(REDUCE_STEP_MS);
host.refresh();
return;
}
paused = !paused;
btn.textContent = paused ? BTN_PLAY : BTN_PAUSE;
sync();
});
host.listen(window, 'resize', function () {
fit();
host.refresh();
});
if (!reduce) {
rafId = requestAnimationFrame(frame);
}
return function () {
cancelAnimationFrame(rafId);
for (let i = 0; i < cleaners.length; i += 1) {
cleaners[i]();
}
};
}
const GAIN_TARGET = 0.8;
const GAIN_RISE = 0.012;
const GAIN_FALL = 0.35;
const SCROLL_PX = 2;
const PER_STEP = 80;
const MAX_GAIN = 8;
const MID_Y = 140;
const HALF_Y = 82;
const PEAK_DECAY = 0.996;
const BURST_EVERY = 150;
const REDUCE_APPEND = 30;
const TXT_GAIN = 'Auto gain';
const TXT_CLIP = 'Clipping';
// Auto gain 한 걸음 — 최근 최댓값을 따라 목표 크기가 되도록 이득을 조절한다 (올릴 땐 천천히, 내릴 땐 빠르게)
function stepGain(gain, peakHold, target, rise, fall) {
const want = clamp(target / Math.max(peakHold, 0.0001), 0.5, MAX_GAIN);
return gain + (want - gain) * (want < gain ? fall : rise);
}
function makeRecordScene(h) {
const nCols = Math.floor(W / SCROLL_PX);
const rawLo = [];
const rawHi = [];
const gains = [];
for (let i = 0; i < nCols; i += 1) {
rawLo.push(0);
rawHi.push(0);
gains.push(1);
}
let gain = 1;
let peakHold = 0.1;
let n = 0;
let k = 0;
let burst = 0;
function level() {
const quiet = 0.1 + 0.05 * Math.sin(k * 0.05);
return quiet + burst * 0.85;
}
function append() {
const lv = level();
let lo = 1e9;
let hi = -1e9;
for (let i = 0; i < PER_STEP; i += 1) {
const ph = (n + i) * 0.19;
const v = lv * (Math.sin(ph) * 0.8 + Math.sin(ph * 2.3 + 0.5) * 0.25) + (hash1(n + i, 21) - 0.5) * 0.04;
if (v < lo) {
lo = v;
}
if (v > hi) {
hi = v;
}
}
n += PER_STEP;
const stepPeak = Math.max(Math.abs(lo), Math.abs(hi));
peakHold = Math.max(stepPeak, peakHold * PEAK_DECAY);
gain = stepGain(gain, peakHold, GAIN_TARGET, GAIN_RISE, GAIN_FALL);
rawLo.shift();
rawHi.shift();
gains.shift();
rawLo.push(lo);
rawHi.push(hi);
gains.push(gain);
}
function clap() {
burst = 1;
if (h.reduce) {
// 움직임 줄이기에서는 흐름 없이 박수 뒤 서른 칸을 한꺼번에 이어 붙여 보여 준다
for (let i = 0; i < REDUCE_APPEND; i += 1) {
k += 1;
append();
burst *= 0.93;
}
}
h.touch();
h.refresh();
}
h.listen(h.canvas, 'pointerdown', function () { clap(); });
h.listen(h.canvas, 'keydown', function (e) {
const key = e.key;
if (key === 'Enter' || key === ' ') {
e.preventDefault();
clap();
}
});
for (let i = 0; i < nCols + 20; i += 1) {
k += 1;
append();
}
return {
step() {
k += 1;
if (h.auto() && k % BURST_EVERY === 0) {
burst = 1;
}
append();
burst *= 0.93;
if (h.reduce) {
burst = burst < 0.02 ? 0 : burst;
}
},
draw() {
const ctx = h.ctx;
paintBg(ctx, BG_TOP, BG_BOT);
ctx.fillStyle = rgba(CREAM, 0.14);
ctx.fillRect(0, MID_Y, W - 24, 1);
let clipped = false;
for (let c = 0; c < nCols; c += 1) {
const x = c * SCROLL_PX;
const g = gains[c];
// 이득을 곱하기 전 모습은 옅게
ctx.fillStyle = rgba(LILAC, 0.3);
ctx.fillRect(x, MID_Y - rawHi[c] * HALF_Y, SCROLL_PX, Math.max(1, (rawHi[c] - rawLo[c]) * HALF_Y));
const hi = rawHi[c] * g;
const lo = rawLo[c] * g;
const over = hi > 1 || lo < -1;
if (over && c > nCols - 12) {
clipped = true;
}
const y1 = MID_Y - clamp(hi, -1, 1) * HALF_Y;
const y2 = MID_Y - clamp(lo, -1, 1) * HALF_Y;
ctx.fillStyle = over ? rgba(PINK, 1) : rgba(MINT, 1);
ctx.fillRect(x, y1, SCROLL_PX, Math.max(1, y2 - y1));
}
// 이득 눈금 — 1배 위치에 가로선
const mx = W - 16;
ctx.fillStyle = rgba(CREAM, 0.14);
ctx.fillRect(mx, 40, 8, 196);
const gy = 236 - clamp(gain / MAX_GAIN, 0, 1) * 196;
ctx.fillStyle = rgba(BUTTER, 1);
ctx.fillRect(mx, gy, 8, 236 - gy);
ctx.fillStyle = rgba(CREAM, 0.8);
ctx.fillRect(mx - 3, 236 - 196 / MAX_GAIN, 14, 1);
// 녹음 표시
ctx.beginPath();
ctx.arc(W - 40, 22, 5, 0, PI2);
ctx.fillStyle = (Math.floor(k / 20) % 2 === 0 || h.reduce) ? rgba(PINK, 1) : rgba(PINK, 0.25);
ctx.fill();
h.say(clipped ? TXT_CLIP + ': ' + gain.toFixed(1) + ' x' : TXT_GAIN + ': ' + gain.toFixed(1) + ' x');
}
};
}
boot(document.getElementById('wfRoot'), makeRecordScene);
})();import { useEffect, useRef } from "react";
import styles from "./WfLiveRecordAppendAutoGain.module.scss";
const W = 480;
const H = 300;
const PI2 = Math.PI * 2;
const FIXED_DT = 16;
const IDLE_STEPS = 220;
const REDUCE_STEP_MS = 900;
const REDUCE_WARM_STEPS = 40;
const BTN_PAUSE = '멈춤';
const BTN_PLAY = '재생';
const BTN_NEXT = '다음 순간';
type RGB = [number, number, number];
// 파스텔 팔레트와 어두운 바탕 두 끝 색
const PINK: RGB = [255, 170, 196];
const MINT: RGB = [150, 226, 196];
const LILAC: RGB = [196, 176, 255];
const SKY_BLUE: RGB = [150, 214, 255];
const BUTTER: RGB = [255, 230, 150];
const CREAM: RGB = [255, 247, 230];
const INK: RGB = [23, 20, 26];
const BG_TOP: RGB = [24, 21, 40];
const BG_BOT: RGB = [48, 42, 78];
interface Host {
ctx: CanvasRenderingContext2D;
canvas: HTMLCanvasElement;
root: HTMLElement;
reduce: boolean;
touch(): void;
auto(): boolean;
refresh(): void;
say(text: string): void;
local(e: MouseEvent): [number, number];
listen(target: EventTarget, type: string, fn: (e: Event) => void, opts?: AddEventListenerOptions): void;
}
interface Scene {
step(): void;
draw(): 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 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)]; }
function rgba(c: RGB, 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 (선형 합동 방식)
function lcg(seed: number): () => number {
let s = seed >>> 0;
return function (): number {
s = (Math.imul(s, 1664525) + 1013904223) >>> 0;
return s / 4294967296;
};
}
// 정수 하나와 시드로 0 이상 1 미만의 값을 만드는 해시 (같은 입력은 늘 같은 값)
function hash1(i: number, seed: number): number {
let h = (Math.imul(i | 0, 374761393) + Math.imul(seed | 0, 668265263)) | 0;
h = Math.imul(h ^ (h >>> 13), 1274126177);
h ^= h >>> 16;
return (h >>> 0) / 4294967296;
}
// 사인 두 개를 음절마다 갈아 끼우고 엔벨로프를 씌운 합성 신호 (소리는 재생하지 않고 수치만 만든다)
function synth(n: number, seed: number): Float32Array {
const rnd = lcg(seed);
const out = new Float32Array(n);
let i = 0;
let p1 = 0;
let p2 = 0;
let peak = 0.0001;
while (i < n) {
const len = 1800 + Math.floor(rnd() * 4200);
const amp = 0.18 + rnd() * 0.82;
const rest = rnd() < 0.18;
const f1 = 0.02 + rnd() * 0.09;
const f2 = f1 * (1.5 + rnd());
const stop = Math.min(n, i + len);
for (let k = i; k < stop; k += 1) {
const x = (k - i) / len;
const env = Math.min(1, x / 0.06) * Math.pow(1 - x, 0.8);
p1 += PI2 * f1;
p2 += PI2 * f2;
const tone = Math.sin(p1) * 0.7 + Math.sin(p2) * 0.3;
const gain = rest ? 0.03 : amp * env;
const v = gain * tone + (rnd() - 0.5) * 0.08 * (rest ? 0.4 : amp);
out[k] = v;
const a = Math.abs(v);
if (a > peak) { peak = a; }
}
i = stop;
}
const norm = 0.92 / peak;
for (let k = 0; k < n; k += 1) { out[k] *= norm; }
return out;
}
// 표본 구간 [a, b) 의 최솟값과 최댓값 — 결과는 rangeLo, rangeHi 에 둔다
let rangeLo = 0;
let rangeHi = 0;
function scanRange(sig: Float32Array, a: number, b: number): void {
const from = Math.max(0, Math.floor(a));
const to = Math.min(sig.length, Math.max(from + 1, Math.ceil(b)));
let lo = 1e9;
let hi = -1e9;
for (let i = from; i < to; i += 1) {
const v = sig[i];
if (v < lo) { lo = v; }
if (v > hi) { hi = v; }
}
if (lo > hi) { lo = 0; hi = 0; }
rangeLo = lo;
rangeHi = hi;
}
function paintBg(ctx: CanvasRenderingContext2D, top: RGB, bot: RGB): void {
const g = ctx.createLinearGradient(0, 0, 0, H);
g.addColorStop(0, rgba(top, 1));
g.addColorStop(1, rgba(bot, 1));
ctx.fillStyle = g;
ctx.fillRect(0, 0, W, H);
}
// 가짜 포인터 — 시연 동안 손이 움직이는 것처럼 보이게 그린다
function drawCursor(ctx: CanvasRenderingContext2D, x: number, y: number, down: boolean): void {
ctx.save();
ctx.translate(x, y);
ctx.beginPath();
ctx.moveTo(0, 0);
ctx.lineTo(0, 15);
ctx.lineTo(4, 11.5);
ctx.lineTo(7.5, 18);
ctx.lineTo(10, 16.8);
ctx.lineTo(6.6, 10.4);
ctx.lineTo(11.5, 10.2);
ctx.closePath();
ctx.fillStyle = rgba(CREAM, 1);
ctx.strokeStyle = rgba(INK, 1);
ctx.lineWidth = 1.4;
ctx.fill();
ctx.stroke();
if (down) {
ctx.beginPath();
ctx.arc(0, 0, 9, 0, PI2);
ctx.strokeStyle = rgba(PINK, 0.9);
ctx.lineWidth = 2;
ctx.stroke();
}
ctx.restore();
}
function boot(root: HTMLElement, make: (h: Host) => Scene): () => void {
const canvasEl = root.querySelector('[data-role="canvas"]');
const statusEl = root.querySelector('[data-role="status"]');
const btnEl = root.querySelector('[data-role="btn"]');
if (!(canvasEl instanceof HTMLCanvasElement) || !statusEl || !(btnEl instanceof HTMLButtonElement)) {
return function (): void { /* 필요한 요소가 없으면 아무것도 하지 않는다 */ };
}
const ctxOrNull = canvasEl.getContext('2d');
if (!ctxOrNull) {
return function (): void { /* 2d 문맥이 없으면 아무것도 하지 않는다 */ };
}
const canvas: HTMLCanvasElement = canvasEl;
const ctx: CanvasRenderingContext2D = ctxOrNull;
const status: Element = statusEl;
const btn: HTMLButtonElement = btnEl;
const reduce = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
const cleaners: Array<() => void> = [];
let paused = false;
let idle = IDLE_STEPS + 1;
let clock = 0;
let lastSayAt = -1e9;
let lastText = status.textContent || '';
let scene: Scene | null = null;
let rafId = 0;
let acc = 0;
let lastTs = -1;
function isAuto(): boolean { return !reduce && !paused && idle > IDLE_STEPS; }
function sync(): void {
const on = isAuto();
if (root.classList.contains('is-demo') !== on) {
root.classList.toggle('is-demo', on);
}
}
function fit(): void {
const r = canvas.getBoundingClientRect();
const dpr = window.devicePixelRatio || 1;
const cw = Math.max(1, Math.round(r.width * dpr));
const ch = Math.max(1, Math.round(r.height * dpr));
canvas.width = cw;
canvas.height = ch;
ctx.setTransform(cw / W, 0, 0, ch / H, 0, 0);
}
const host: Host = {
ctx,
canvas,
root,
reduce,
touch(): void {
idle = 0;
sync();
},
auto: isAuto,
refresh(): void {
if (scene) { scene.draw(); }
},
say(text: string): void {
if (text === lastText) { return; }
if (!reduce && clock - lastSayAt < 250) { return; }
lastText = text;
lastSayAt = clock;
// 시연이 혼자 돌 때는 읽어 주지 않고, 사람이 만졌을 때만 알린다
status.setAttribute('aria-live', isAuto() ? 'off' : 'polite');
status.textContent = text;
},
local(e: MouseEvent): [number, number] {
const r = canvas.getBoundingClientRect();
return [clamp((e.clientX - r.left) * W / Math.max(1, r.width), 0, W), clamp((e.clientY - r.top) * H / Math.max(1, r.height), 0, H)];
},
listen(target: EventTarget, type: string, fn: (e: Event) => void, opts?: AddEventListenerOptions): void {
target.addEventListener(type, fn, opts);
cleaners.push(function (): void { target.removeEventListener(type, fn, opts); });
}
};
function advance(ms: number): void {
if (!scene) { return; }
const n = Math.max(1, Math.round(ms / FIXED_DT));
for (let i = 0; i < n; i += 1) {
idle += 1;
clock += FIXED_DT;
scene.step();
}
}
function frame(ts: number): void {
if (lastTs < 0) { lastTs = ts; }
const dt = Math.min(ts - lastTs, 160);
lastTs = ts;
if (!paused && scene) {
acc += dt;
while (acc >= FIXED_DT) {
idle += 1;
clock += FIXED_DT;
scene.step();
acc -= FIXED_DT;
}
sync();
scene.draw();
}
rafId = requestAnimationFrame(frame);
}
scene = make(host);
btn.textContent = reduce ? BTN_NEXT : BTN_PAUSE;
fit();
if (reduce) {
root.classList.remove('is-demo');
advance(REDUCE_WARM_STEPS * FIXED_DT);
}
scene.draw();
host.listen(btn, 'click', function (): void {
if (reduce) {
advance(REDUCE_STEP_MS);
host.refresh();
return;
}
paused = !paused;
btn.textContent = paused ? BTN_PLAY : BTN_PAUSE;
sync();
});
host.listen(window, 'resize', function (): void {
fit();
host.refresh();
});
if (!reduce) {
rafId = requestAnimationFrame(frame);
}
return function (): void {
cancelAnimationFrame(rafId);
for (let i = 0; i < cleaners.length; i += 1) { cleaners[i](); }
};
}
const GAIN_TARGET = 0.8;
const GAIN_RISE = 0.012;
const GAIN_FALL = 0.35;
const SCROLL_PX = 2;
const PER_STEP = 80;
const MAX_GAIN = 8;
const MID_Y = 140;
const HALF_Y = 82;
const PEAK_DECAY = 0.996;
const BURST_EVERY = 150;
const REDUCE_APPEND = 30;
const TXT_GAIN = '자동 이득';
const TXT_CLIP = '넘침';
// 자동 이득 한 걸음 — 최근 최댓값을 따라 목표 크기가 되도록 이득을 조절한다 (올릴 땐 천천히, 내릴 땐 빠르게)
function stepGain(gain: number, peakHold: number, target: number, rise: number, fall: number): number {
const want = clamp(target / Math.max(peakHold, 0.0001), 0.5, MAX_GAIN);
return gain + (want - gain) * (want < gain ? fall : rise);
}
function makeRecordScene(h: Host): Scene {
const nCols = Math.floor(W / SCROLL_PX);
const rawLo: number[] = [];
const rawHi: number[] = [];
const gains: number[] = [];
for (let i = 0; i < nCols; i += 1) { rawLo.push(0); rawHi.push(0); gains.push(1); }
let gain = 1;
let peakHold = 0.1;
let n = 0;
let k = 0;
let burst = 0;
function level(): number {
const quiet = 0.1 + 0.05 * Math.sin(k * 0.05);
return quiet + burst * 0.85;
}
function append(): void {
const lv = level();
let lo = 1e9;
let hi = -1e9;
for (let i = 0; i < PER_STEP; i += 1) {
const ph = (n + i) * 0.19;
const v = lv * (Math.sin(ph) * 0.8 + Math.sin(ph * 2.3 + 0.5) * 0.25) + (hash1(n + i, 21) - 0.5) * 0.04;
if (v < lo) { lo = v; }
if (v > hi) { hi = v; }
}
n += PER_STEP;
const stepPeak = Math.max(Math.abs(lo), Math.abs(hi));
peakHold = Math.max(stepPeak, peakHold * PEAK_DECAY);
gain = stepGain(gain, peakHold, GAIN_TARGET, GAIN_RISE, GAIN_FALL);
rawLo.shift();
rawHi.shift();
gains.shift();
rawLo.push(lo);
rawHi.push(hi);
gains.push(gain);
}
function clap(): void {
burst = 1;
if (h.reduce) {
// 움직임 줄이기에서는 흐름 없이 박수 뒤 서른 칸을 한꺼번에 이어 붙여 보여 준다
for (let i = 0; i < REDUCE_APPEND; i += 1) {
k += 1;
append();
burst *= 0.93;
}
}
h.touch();
h.refresh();
}
h.listen(h.canvas, 'pointerdown', function (): void { clap(); });
h.listen(h.canvas, 'keydown', function (e: Event): void {
const key = (e as KeyboardEvent).key;
if (key === 'Enter' || key === ' ') {
e.preventDefault();
clap();
}
});
for (let i = 0; i < nCols + 20; i += 1) {
k += 1;
append();
}
return {
step(): void {
k += 1;
if (h.auto() && k % BURST_EVERY === 0) { burst = 1; }
append();
burst *= 0.93;
if (h.reduce) { burst = burst < 0.02 ? 0 : burst; }
},
draw(): void {
const ctx = h.ctx;
paintBg(ctx, BG_TOP, BG_BOT);
ctx.fillStyle = rgba(CREAM, 0.14);
ctx.fillRect(0, MID_Y, W - 24, 1);
let clipped = false;
for (let c = 0; c < nCols; c += 1) {
const x = c * SCROLL_PX;
const g = gains[c];
// 이득을 곱하기 전 모습은 옅게
ctx.fillStyle = rgba(LILAC, 0.3);
ctx.fillRect(x, MID_Y - rawHi[c] * HALF_Y, SCROLL_PX, Math.max(1, (rawHi[c] - rawLo[c]) * HALF_Y));
const hi = rawHi[c] * g;
const lo = rawLo[c] * g;
const over = hi > 1 || lo < -1;
if (over && c > nCols - 12) { clipped = true; }
const y1 = MID_Y - clamp(hi, -1, 1) * HALF_Y;
const y2 = MID_Y - clamp(lo, -1, 1) * HALF_Y;
ctx.fillStyle = over ? rgba(PINK, 1) : rgba(MINT, 1);
ctx.fillRect(x, y1, SCROLL_PX, Math.max(1, y2 - y1));
}
// 이득 눈금 — 1배 위치에 가로선
const mx = W - 16;
ctx.fillStyle = rgba(CREAM, 0.14);
ctx.fillRect(mx, 40, 8, 196);
const gy = 236 - clamp(gain / MAX_GAIN, 0, 1) * 196;
ctx.fillStyle = rgba(BUTTER, 1);
ctx.fillRect(mx, gy, 8, 236 - gy);
ctx.fillStyle = rgba(CREAM, 0.8);
ctx.fillRect(mx - 3, 236 - 196 / MAX_GAIN, 14, 1);
// 녹음 표시
ctx.beginPath();
ctx.arc(W - 40, 22, 5, 0, PI2);
ctx.fillStyle = (Math.floor(k / 20) % 2 === 0 || h.reduce) ? rgba(PINK, 1) : rgba(PINK, 0.25);
ctx.fill();
h.say(clipped ? TXT_CLIP + ': ' + gain.toFixed(1) + ' x' : TXT_GAIN + ': ' + gain.toFixed(1) + ' x');
}
};
}
export default function WfLiveRecordAppendAutoGain() {
const rootRef = useRef<HTMLDivElement | null>(null);
useEffect(() => {
const root = rootRef.current;
if (!root) return;
return boot(root, makeRecordScene);
}, []);
return (
<main className={styles.stage}>
<div className={`${styles.wf} is-demo`} ref={rootRef}>
<canvas className={styles.canvas} data-role="canvas" width={480} height={300} tabIndex={0} aria-label="녹음 중인 소리가 오른쪽에서 이어 붙고 자동 이득이 작은 소리를 끌어올리는 파형" />
<p className={styles.status} data-role="status" aria-live="polite">자동 이득</p>
<button className={styles.btn} data-role="btn" type="button">멈춤</button>
<p className={styles.caption}>녹음 중인 소리가 오른쪽에서 이어 붙고 자동 이득이 작은 소리를 끌어올리는 파형</p>
</div>
</main>
);
}09 A Waveform Where Live Recording Appends on the Right and Auto Gain Lifts Quiet Sounds — Measured area 33.41% · moving frames 23/23Original by GODRICH · SCSS and React ship in the zip · CSS Waveform: 9 Peak Columns and Trim Pickers
The post this demo lives in
CSS Waveform: 9 Peak Columns and Trim PickersA css waveform starts with squeezing thousands of samples into pixel columns — scene 01's min/max buckets and scene 05's See all demos in this post
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