## Installation

CoherentNoise.jl exists in the Julia's General registry. In Julia ≥ 1.0, you can add it using the package manager with:

pkg> add CoherentNoise

## Basic Usage

The following is only a brief explanation of basic usage. For more advanced usage examples, please see the Tutorial section.

To get started, let's get a feel for how to create a sampler for one of the supported noise algorithms, and sample from it. Perlin Improved noise is a well-known algorithm, so let's create a 2-dimensional Perlin Improved noise sampler and sample from it:

using CoherentNoise
sampler = perlin_2d()
sample(sampler, 120.2, 42.8)
-0.0708458905600019

To create a sampler, we simply call the function corresponding to the noise algorithm and dimensionality. We can then sample from it using the sample function, passing in as arguments a sampler, and multiple Real arguments corresponding to the coordinates in the sampler's noise space. In this example, we have a 2-dimensional sampler, so we passed 2 numbers; one for the coordinate along the X axis, and one for the coordinate along the Y axis.

Note

It is strongly recommended to use floating-point numbers with a fractional component (non-zero value after the decimal point), as some algorithms (notably older gradient noises like Perlin Noise or Perlin "Improved Noise"), will return zero for integral coordinates.

All samplers have their own distinct random number generator, and it is how we can retrieve different results with the same input coordinates. By default, a sampler's seed is set to nothing, which corresponds to using your machine's hardware random number generator to create a seed. This will result in non-deterministic results, as each instance of a sampler will produce different results when sampled from. We can change the seed on a per-sampler basis, by passing the seed keyword argument, in order to have reproducible results:

sampler = perlin_2d(seed=42)
sample(sampler, 120.2, 42.8)
0.4476778905600064

In summary, one creates a sampler by calling a function for the desired algorithm and dimensionality, and we can alter the the sampler's output by changing its seed.

Of particular note is that all samplers accept a seed keyword argument; even those that don't make use of any random numbers in their implementation. This is required for the composition pipeline feature described in the Tutorial.