party-js/lib/systems/variation.js

A JavaScript library to brighten up your user's site experience with visual effects!

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.gradientSample = exports.splineSample = exports.skewRelative = exports.skew = exports.range = exports.evaluateVariation = void 0;
var random_1 = require("./random");
/**
 * Returns a value instance of a variation.
 */
function evaluateVariation(variation) {
    if (Array.isArray(variation))
        return random_1.pick(variation);
    if (typeof variation === "function")
        return variation();
    return variation;
}
exports.evaluateVariation = evaluateVariation;
/**
 * Creates a variation function that returns a random number from min to max.
 */
function range(min, max) {
    return function () { return random_1.randomRange(min, max); };
}
exports.range = range;
/**
 * Creates a variation function that skews the specified value by a specified, absolute
 * amount. This means that instead of the value itself, a random number that deviates
 * at most by the specified amount is returned.
 *
 * @remarks
 * If you want to skew by a percentage instead, use `skewRelative`.
 */
function skew(value, amount) {
    return function () { return value + random_1.randomRange(-amount, amount); };
}
exports.skew = skew;
/**
 * Creates a variation function that skews the specified value by a specified percentage.
 * This means that instead of the value itself, a random number that deviates by a maximum
 * of the specified percentage is returned.
 */
function skewRelative(value, percentage) {
    return function () { return value * (1 + random_1.randomRange(-percentage, percentage)); };
}
exports.skewRelative = skewRelative;
/**
 * Creates a variation function that returns a random sample from the given spline.
 *
 * @param spline The spline to sample from.
 */
function splineSample(spline) {
    return function () { return spline.evaluate(Math.random()); };
}
exports.splineSample = splineSample;
/**
 * Creates a variation function that returns a random sample from the given gradient.
 *
 * @remarks
 * This function is an alias for the spline variation, since a gradient is just
 * a spline under the hood.
 *
 * @param gradient The gradient to sample from.
 */
function gradientSample(gradient) {
    return splineSample(gradient);
}
exports.gradientSample = gradientSample;