37 lines
787 B
JavaScript
37 lines
787 B
JavaScript
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import { getMode } from './modes.js';
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/*
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Generate a random number between `min` and `max`
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*/
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const rand = ([min, max]) => min + Math.random() * (max - min);
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/*
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Convert a constraints object to intervals.
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*/
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const to_intervals = constraints =>
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Object.keys(constraints).reduce((o, k) => {
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let v = constraints[k];
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o[k] = Array.isArray(v) ? v : [v, v];
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return o;
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}, {});
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/*
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Generate a random color.
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*/
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const random = (mode = 'rgb', constraints = {}) => {
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let def = getMode(mode);
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let limits = to_intervals(constraints);
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return def.channels.reduce(
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(res, ch) => {
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// ignore alpha if not present in constraints
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if (limits.alpha || ch !== 'alpha') {
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res[ch] = rand(limits[ch] || def.ranges[ch]);
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}
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return res;
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},
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{ mode }
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);
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};
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export default random;
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