Michael Freno
67032460ff
- ProgressBar: full-width played/remaining bar in the player pane, click-to-seek; waveform no longer handles seeking or the played/future color split (pure visual) - bars: 2 terminal rows per bar (16 levels) via barChars, partial block in the top row so the column renders continuously - fix bars maxing at audio start: disable cava autosens (silence gain-ramp), pre-warm the malloc'd FFT window with zeros, skip partial FFT windows - createBarScaler peak follower + power curve replaces cava autosens for level-to-height mapping (src/utils/bar-mapping.ts, unit-tested)
103 lines
3.6 KiB
TypeScript
103 lines
3.6 KiB
TypeScript
/**
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* Pure bar-scaling helpers for the terminal waveform.
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*
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* barChars maps a 0..16 level to the two characters of a 2-row bar built
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* from Unicode lower block elements (U+2581..U+2588). The partial block
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* sits in the TOP row (its glyph bottom edge = row bottom), so a full
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* block below makes a visually continuous 2-cell column — the "double the
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* default height" requirement (each bar = 2 terminal rows, 16 heights).
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*
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* createBarScaler is a stateful fast-attack / slow-release peak follower
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* that replaces cava's autosens: a loud start cannot pin every bar at
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* full height (the peak follower absorbs it) and quiet content gets
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* normalized up.
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*/
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// ── Types ────────────────────────────────────────────────────────────
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export interface BarScalerOptions {
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/** Peak follower decay per frame (default: 0.985) */
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release?: number;
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/** Power curve applied after normalization (default: 0.7) */
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curve?: number;
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/** Silence threshold — below this the input is treated as silent (default: 1e-6) */
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epsilon?: number;
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}
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// ── Constants ────────────────────────────────────────────────────────
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/** Number of discrete bar heights (2 rows × 8 block levels). */
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export const BAR_LEVELS = 16;
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/** Lower block elements, index 0 = space (silence) through full block (max). */
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const LOWER = [
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" ",
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"\u2581",
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"\u2582",
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"\u2583",
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"\u2584",
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"\u2585",
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"\u2586",
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"\u2587",
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"\u2588",
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];
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// ── Bar mapping ──────────────────────────────────────────────────────
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/**
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* Map a bar level (0..16) to the two characters that render it as a
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* 2-row column: top row + bottom row.
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*
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* level 0 → { top: " ", bottom: " " }
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* level 1..8 → { top: " ", bottom: LOWER[level] }
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* level 9..16 → { top: LOWER[level - 8], bottom: "\u2588" }
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*/
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export function barChars(level: number): { top: string; bottom: string } {
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const raw = Math.floor(level);
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const lvl = Number.isFinite(raw)
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? Math.max(0, Math.min(BAR_LEVELS, raw))
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: 0;
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if (lvl === 0) return { top: " ", bottom: " " };
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if (lvl <= 8) return { top: " ", bottom: LOWER[lvl] };
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return { top: LOWER[lvl - 8], bottom: "\u2588" };
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}
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// ── Peak-follower scaler ─────────────────────────────────────────────
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const clamp01 = (value: number): number => Math.max(0, Math.min(1, value));
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/**
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* Create a stateful bar scaler. Each call normalizes its input against a
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* peak follower (instant attack, multiplicative release), then applies a
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* power curve so low-energy content remains visible. Returns a new
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* number[] per call.
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*/
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export function createBarScaler(
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opts?: BarScalerOptions,
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): (values: ArrayLike<number>) => number[] {
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const release = opts?.release ?? 0.985;
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const curve = opts?.curve ?? 0.7;
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const epsilon = opts?.epsilon ?? 1e-6;
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let peak = 0;
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return (values: ArrayLike<number>): number[] => {
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let frameMax = 0;
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for (let i = 0; i < values.length; i++) {
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const magnitude = Math.abs(values[i]);
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if (magnitude > frameMax) frameMax = magnitude;
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}
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// Fast attack, slow release
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peak = frameMax > peak ? frameMax : peak * release;
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const gain = peak > epsilon ? 1 / peak : 0;
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const output = new Array<number>(values.length);
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for (let i = 0; i < values.length; i++) {
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output[i] = Math.pow(clamp01(values[i] * gain), curve);
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}
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return output;
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};
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}
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