import { createNoise2D } from 'simplex-noise'
import RandomGenerator from './RandomGenerator'

export default class NoiseGenerator {

    /**
     * Generates noise with a uniform distribution.
     */
    public static uniform(rng: RandomGenerator, min: number = 0, max: number = 1): number {
        return rng.uniformFloat(0, 1) * (max - min) + min
    }

    /**
     * Generates noise with a Gaussian distribution.
     */
    public static gaussian(rng: RandomGenerator, mean: number = 0, stdDev: number = 1): number {
        const c = rng.normalFloat(mean, stdDev)
        return c * stdDev + mean
    }

    /**
     * Generates completely random values with no correlation between successive outputs.
     */
    public static white(rng: RandomGenerator, stdDev: number = 1): number {
        return (rng.uniformFloat(0, 1) * 2 - 1) * stdDev
    }

    /**
     * Generates 2D Simplex noise with output [-1, 1].
     */
    public static simplex(rng: RandomGenerator): (x: number, y: number) => number {
        return createNoise2D(() => rng.uniformFloat(0, 1))
    }
}