55 lines
1.2 KiB
JavaScript
55 lines
1.2 KiB
JavaScript
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/**
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* Minimal signal/observable for reactive UI updates.
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* No framework dependency. ~40 lines.
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*
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* @module shapeseq/signal
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*/
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export function createSignal(initialValue) {
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let value = initialValue;
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const subscribers = new Set();
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function get() { return value; }
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function set(newValue) {
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if (newValue === value) return;
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value = newValue;
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for (const fn of subscribers) fn(value);
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}
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function subscribe(fn) {
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subscribers.add(fn);
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return () => subscribers.delete(fn);
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}
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return { get, set, subscribe };
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}
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/**
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* Signal backed by a Float32Array for param vectors.
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* Subscribers are called when any element changes.
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*/
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export function createArraySignal(length) {
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const value = new Float32Array(length);
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const subscribers = new Set();
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function get() { return value; }
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function update(newArray) {
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let changed = false;
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for (let i = 0; i < value.length && i < newArray.length; i++) {
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if (value[i] !== newArray[i]) { value[i] = newArray[i]; changed = true; }
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}
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if (changed) {
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for (const fn of subscribers) fn(value);
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}
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}
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function subscribe(fn) {
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subscribers.add(fn);
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return () => subscribers.delete(fn);
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}
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return { get, update, subscribe };
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}
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