pex-random v2.1.0
pex-random
Random value generators (float, int, vector and noise) for PEX.
Installation
npm install pex-random
Usage
import random from "pex-random";
// Use global PRNG
console.log(random.float());
// => unpredictable (seeded by performance.now())
// Seed global PRNG
random.seed("0");
console.log(random.float());
// => predictable, always returns: 0.8071179636424909
// Use local PRNG
const localRandom = random.create();
console.log(localRandom.float());
// => unpredictable (seeded by performance.now() + INCREMENT)
// Use seeded local PRNG
const localSeededRandom = random.create("0");
console.log(localSeededRandom.float());
// => predictable, always returns: 0.8071179636424909
Notes:
- noise2/3/4: coordinates must be between -2^31 and 2^31. Eg. using
Date.now()
is not viable butperformance.now()
is. - similar seeds might not result in different starting values
API
Modules
Classes
Typedefs
pex-random
Summary: Export a Random instance using the global PRNG:
- The instance is seeded by
performance.now()
- Call
random.seed("seed")
to overwrite the global PRNG: all other calls torandom.float()
will derive from the new seeded state. - Call
random.create()
to create a local instance of Random with a separate unpredictable PRNG. - Call
random.create("seed")
to create a local instance of Random with a separate predictable PRNG: all other calls torandom.float()
will derive from the new seeded state.
Random
Kind: global class
- Random
- new Random([seed])
- .create ⇒ Random
- .seed(s)
- .float([min], [max]) ⇒ number
- .int([min], [max]) ⇒ number
- .vec2([r]) ⇒ module:pex-math~vec2
- .vec3([r]) ⇒ module:pex-math~vec3
- .vec2InRect(rect) ⇒ module:pex-math~vec2
- .vec3InAABB(bbox) ⇒ module:pex-math~vec3
- .quat() ⇒ module:pex-math~quat
- .chance([probability]) ⇒ boolean
- .element(list) ⇒ *
- .noise2(x, y) ⇒ number
- .noise3(x, y, z) ⇒ number
- .noise4(x, y, z, w) ⇒ number
- .fbm(options, ...d) ⇒ number
new Random(seed)
Creates an instance of Random.
Param | Type | Default |
---|---|---|
seed | string | number | "Random.NOW + Random.#instanceCount" |
random.create ⇒ Random
Create an instance of Random.
Kind: instance property of Random
Param | Type | Description |
---|---|---|
seed | string | number | If omitted, the global PRNG seed will be used and incremented for each local PRNG. |
random.seed(s)
Set the seed for the random number generator.
Kind: instance method of Random
Param | Type | Description |
---|---|---|
s | string | Seed value |
random.float(min, max) ⇒ number
Get a float between min and max. Defaults to:
0 <= x < 1
if no argument supplied0 <= x < max
if only one argument supplied
Kind: instance method of Random
Param | Type |
---|---|
min | number |
max | number |
random.int(min, max) ⇒ number
Get an int between min and max. Defaults to:
0 <= x < Number.MAX_SAFE_INTEGER
if no argument supplied0 <= x < max
if only one argument supplied
Kind: instance method of Random
Param | Type |
---|---|
min | number |
max | number |
random.vec2(r) ⇒ module:pex-math~vec2
Get a vec2 included in a radius.
Kind: instance method of Random
Param | Type | Default | Description |
---|---|---|---|
r | number | 1 | radius |
random.vec3(r) ⇒ module:pex-math~vec3
Get a vec3 included in a radius.
Kind: instance method of Random
Param | Type | Default | Description |
---|---|---|---|
r | number | 1 | radius |
random.vec2InRect(rect) ⇒ module:pex-math~vec2
Get a vec2 included in a rectangle.
Kind: instance method of Random
Param | Type | Description |
---|---|---|
rect | number | rectangle |
random.vec3InAABB(bbox) ⇒ module:pex-math~vec3
Get a vec3 included in a rectangle bbox.
Kind: instance method of Random
Param | Type | Description |
---|---|---|
bbox | number | rectangle bbox |
random.quat() ⇒ module:pex-math~quat
Get a random quaternion.
Kind: instance method of Random See
random.chance(probability) ⇒ boolean
Returns a chance of an event occuring according to a given probability between 0 and 1.
Kind: instance method of Random
Param | Type | Default | Description |
---|---|---|---|
probability | number | 0.5 | Float between 0 and 1. |
random.element(list) ⇒ *
Gets a random element from a list.
Kind: instance method of Random
Param | Type |
---|---|
list | Array |
random.noise2(x, y) ⇒ number
Samples the noise field in 2 dimensions.
Kind: instance method of Random Returns: number - in the interval -1, 1
Param | Type |
---|---|
x | number |
y | number |
random.noise3(x, y, z) ⇒ number
Samples the noise field in 3 dimensions.
Kind: instance method of Random Returns: number - in the interval -1, 1
Param | Type |
---|---|
x | number |
y | number |
z | number |
random.noise4(x, y, z, w) ⇒ number
Samples the noise field in 4 dimensions.
Kind: instance method of Random Returns: number - in the interval -1, 1
Param | Type |
---|---|
x | number |
y | number |
z | number |
w | number |
random.fbm(options, ...d) ⇒ number
Fractional Brownian motion (also called fractal Brownian motion) noise. Default to 1/f noise with 8 octaves.
Kind: instance method of Random Returns: number - in the interval -1, 1
Param | Type | Description |
---|---|---|
options | FBMOptions | |
...d | number | x, y, z?, w? |
FBMOptions
Kind: global typedef Properties
Name | Type | Default |
---|---|---|
octaves | number | 8 |
lacunarity | number | 2 |
gain | number | 0.5 |
frequency | number | 1 |
amplitude | number | gain |
noise | function |
License
MIT. See license file.
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