2.5. Random generator library

The RANDOM module implements pseudo-random number generation using a linear congruential generator with vectorized state (int4). It provides integer, float, and vector random values, as well as geometric sampling (unit vectors, points in spheres and disks).

All functions and symbols are in “random” module, use require to get access to it.

require daslib/random

Example:

require daslib/random

    [export]
    def main() {
        var seed = random_seed(12345)
        print("int: {random_int(seed)}\n")
        print("float: {random_float(seed)}\n")
        print("float: {random_float(seed)}\n")
    }
    // output:
    // int: 7584
    // float: 0.5848567
    // float: 0.78722495

2.5.1. Constants

LCG_RAND_MAX = 32767

maximum possible output of random number generator

LCG_RAND_MAX_BIG = 1073741823

maximum possible output of random_big_int

2.5.2. Seed and basic generators

random_big_int(seed: int4&): auto

random integer 0..32768*32768-1 (LCG_RAND_MAX_BIG)

Arguments:

  • seed : int4&

random_float(seed: int4&): auto

random float 0..1

Arguments:

  • seed : int4&

random_float4(seed: int4&): auto

random float4, each component is 0..1

Arguments:

  • seed : int4&

random_int(seed: int4&): auto

random integer 0..32767 (LCG_RAND_MAX)

Arguments:

  • seed : int4&

random_int4(seed: int4&): auto

random int4, each component is 0..32767 (LCG_RAND_MAX)

Arguments:

  • seed : int4&

random_seed(seed: int): auto

constructs seed vector out of single integer seed

Arguments:

  • seed : int

random_seed2D(seed: int4&; co: int2; cf: int = 0): auto

constructs seed vector out of 2d screen coordinates and frame counter cf

Arguments:

  • seed : int4&

  • co : int2

  • cf : int

random_uint(seed: int4&): auto

random unsigned integer using 3-component LCG, covering full uint range

Arguments:

  • seed : int4&

2.5.3. Random iterators

each_random_uint(rnd_seed: int = 13): iterator<uint>

infinite generator of random uints initialized with rnd_seed

Arguments:

  • rnd_seed : int

2.5.4. Specific distributions

random_in_unit_disk(seed: int4&): auto

Returns a random float3 point uniformly distributed inside the unit disk (length <= 1, z=0).

Arguments:

  • seed : int4&

random_in_unit_sphere(seed: int4&): auto

Returns a random float3 point uniformly distributed inside the unit sphere (length <= 1).

Arguments:

  • seed : int4&

random_unit_vector(seed: int4&): auto

random float3 unit vector (length=1.)

Arguments:

  • seed : int4&