Random value generators (float, int, vector and noise) for PEX.
npm install pex-random
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
- FBMOptions
-
vec2 :
module:pex-math~vec2
-
vec3 :
module:pex-math~vec3
-
quat :
module:pex-math~quat
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.
Kind: global class
-
pex-random
- new Random([seed])
-
.create ⇒
Random
- .seed(s)
-
.float([min], [max]) ⇒
number
-
.int([min], [max]) ⇒
number
-
.vec2([r]) ⇒
vec2
-
.vec3([r]) ⇒
vec3
-
.vec2InRect(rect) ⇒
vec2
-
.vec3InAABB(bbox) ⇒
vec3
-
.quat() ⇒
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
Creates an instance of Random.
Param | Type | Default |
---|---|---|
[seed] |
string | number
|
"Random.NOW + Random.#instanceCount" |
Create an instance of Random.
Kind: instance property of pex-random
Param | Type | Description |
---|---|---|
[seed] |
string | number
|
If omitted, the global PRNG seed will be used and incremented for each local PRNG. |
Set the seed for the random number generator.
Kind: instance method of pex-random
Param | Type | Description |
---|---|---|
s | string |
Seed value |
Get a float between min and max. Defaults to:
-
0 <= x < 1
if no argument supplied -
0 <= x < max
if only one argument supplied
Kind: instance method of pex-random
Param | Type |
---|---|
[min] | number |
[max] | number |
Get an int between min and max. Defaults to:
-
0 <= x < Number.MAX_SAFE_INTEGER
if no argument supplied -
0 <= x < max
if only one argument supplied
Kind: instance method of pex-random
Param | Type |
---|---|
[min] | number |
[max] | number |
pex-random.vec2([r]) ⇒ vec2
Get a vec2 included in a radius.
Kind: instance method of pex-random
Param | Type | Default | Description |
---|---|---|---|
[r] | number |
1 |
radius |
pex-random.vec3([r]) ⇒ vec3
Get a vec3 included in a radius.
Kind: instance method of pex-random
Param | Type | Default | Description |
---|---|---|---|
[r] | number |
1 |
radius |
pex-random.vec2InRect(rect) ⇒ vec2
Get a vec2 included in a rectangle.
Kind: instance method of pex-random
Param | Type | Description |
---|---|---|
rect | number |
rectangle |
pex-random.vec3InAABB(bbox) ⇒ vec3
Get a vec3 included in a rectangle bbox.
Kind: instance method of pex-random
Param | Type | Description |
---|---|---|
bbox | number |
rectangle bbox |
pex-random.quat() ⇒ quat
Get a random quaternion.
Kind: instance method of pex-random
See
- [Graphics Gems III, Edited by David Kirk, III.6 UNIFORM RANDOM ROTATIONS]
- Steve LaValle
Returns a chance of an event occuring according to a given probability between 0 and 1.
Kind: instance method of pex-random
Param | Type | Default | Description |
---|---|---|---|
[probability] | number |
0.5 |
Float between 0 and 1. |
Gets a random element from a list.
Kind: instance method of pex-random
Param | Type |
---|---|
list | Array |
Samples the noise field in 2 dimensions.
Kind: instance method of pex-random
Returns: number
- in the interval [-1, 1]
Param | Type |
---|---|
x | number |
y | number |
Samples the noise field in 3 dimensions.
Kind: instance method of pex-random
Returns: number
- in the interval [-1, 1]
Param | Type |
---|---|
x | number |
y | number |
z | number |
Samples the noise field in 4 dimensions.
Kind: instance method of pex-random
Returns: number
- in the interval [-1, 1]
Param | Type |
---|---|
x | number |
y | number |
z | number |
w | number |
Fractional Brownian motion (also called fractal Brownian motion) noise. Default to 1/f noise with 8 octaves.
Kind: instance method of pex-random
Returns: number
- in the interval [-1, 1]
Param | Type | Description |
---|---|---|
options | FBMOptions |
|
...d | number |
x, y, z?, w? |
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 |
Kind: global typedef
MIT. See license file.