Math

Processing numbers, randomness, etc.

cm.clamp(value, min, max)

Constrains the input value within the specified range [min, max].

const x = 10;
cm.clamp(10, 2, 8); // 8
cm.clamp(10, 2, 12); // 10
cm.clamp(10, 12, 20); // 12

cm.random([min[, max]])

Generates random number with a uniform distribution, which is within range [min, max). If min is not specified, it defaults to 0; if max is not specified, it defaults to 1.

cm.random(); // 0.4418278691734798
cm.random(10); // 3.747820060823679
cm.random(2, 10); // 6.649642684087617

cm.randomInt([min[, max]])

Like cm.random, expect returns integers.

cm.randomInt(0, 10); // 5

cm.randomNoise(min[, max[, options]])

Returns a function with the specified options for generating random numbers with a smooth, continuous random-like distribution, commonly referred to as [Perlin Noise](Perlin Noise), which is within range [min, max). If min is not specified, it defaults to 0; if max is not specified, it defaults to 1.

Supports following options:

octaves - layers of noise, default to 4.
seed - seed for generated sequence, a real number or as any integer, defaults to random number.
falloff - falloff factor for each octave, a real number or as any integer, defaults to 0.5.

Increasing the number of octaves results in a more variable sequence, and two generators instanced with the same seed and octaves generate the same sequence.

The returned function accept two parameters: x is x coordinate in noise space; y is y coordinate in noise space.

cm.randomNoise()(0.2, 0.1); // 0.04076453205333332
cm.randomNoise(6, 2)(0.2, 0.1); // -0.08489767172063487

cm.randomNormal([mu[, sigma]])

Returns a function for generating random numbers with a [normal(Gaussian) distribution](normal(Gaussian) distribution). The expected value of the generated number is mu, with given standard deviation sigma. If mu is not specified, it defaults to 0; if sigma is not specified, it defaults to 1.

cm.randomNormal()(); // -2.0897431210663022
cm.randomNormal(30, 10)(); // 31.94829616303788

cm.randomChar()

Returns a random printable and non-empty character.

cm.randomChar(); // 'A'