Isotope.Noise (Isotope v0.5.0)

Copy Markdown View Source

Create noise generators, sample individual points, and generate noise maps.

Creating a Noise Generator

All noise operations require a noise reference, created with new/0 or new/1:

{:ok, noise} = Isotope.Noise.new()
{:ok, noise} = Isotope.Noise.new(%Isotope.Options{
  seed: 42,
  noise_type: :perlin_fractal,
  frequency: 0.02,
  fractal_options: %Isotope.Options.Fractal{octaves: 6, gain: 0.5}
})

Generating Noise Maps

noise_map/2 generates a full map starting at the origin. chunk/4 generates a region starting at an arbitrary coordinate, useful for tiling or infinite worlds:

nm = Isotope.Noise.noise_map(noise, {256, 256})
chunk = Isotope.Noise.chunk(noise, {512, 512}, 256, 256)

Both return an %Isotope.NoiseMap{} struct. See Isotope.NoiseMap for accessors.

Sampling Individual Points

Use get_noise/2 with a 2D or 3D coordinate tuple:

value = Isotope.Noise.get_noise(noise, {1.5, 2.5})
value = Isotope.Noise.get_noise(noise, {1.5, 2.5, 3.5})

Coordinates are passed directly to the underlying noise algorithm. Use the frequency option to control the scale of the noise.

Supported Noise Types

:perlin, :perlin_fractal, :simplex, :simplex_fractal, :value, :value_fractal, :cubic, :cubic_fractal, :cellular, :white

Summary

Types

A coordinate {x, y} in a cartesian plane.

A reference to the noise generator. This is needed for most of the library functions.

A noise map containing packed f32 noise values with dimensions.

Options available when initializing the noise.

2-element tuple containg x and y values as floats.

3-element tuple containg x, y and z values as floats.

A tuple containing width and height

Functions

Returns a 2D noise map from start_point which has width and height

Returns the 2D or 3D noise value depending on axes. If axes is a 2-float tuple, it will return the 2D noise value for the point. If axes is a 3-float tuple, it will return the 3D noise value for the point.

Returns a new noise reference using the default options.

Returns a new noise reference using the provided options.

Generates a 2D noise map of size and returns it.

Types

coord()

@type coord() :: {integer(), integer()}

A coordinate {x, y} in a cartesian plane.

noise_ref()

@type noise_ref() :: reference()

A reference to the noise generator. This is needed for most of the library functions.

noisemap()

@type noisemap() :: Isotope.NoiseMap.t()

A noise map containing packed f32 noise values with dimensions.

options()

@type options() :: Isotope.Options.t()

Options available when initializing the noise.

point2d()

@type point2d() :: {float(), float()}

2-element tuple containg x and y values as floats.

point3d()

@type point3d() :: {float(), float(), float()}

3-element tuple containg x, y and z values as floats.

size()

@type size() :: {non_neg_integer(), non_neg_integer()}

A tuple containing width and height

Functions

chunk(noise, start_point, width, height)

@spec chunk(noise_ref(), coord(), non_neg_integer(), non_neg_integer()) :: noisemap()

Returns a 2D noise map from start_point which has width and height

iex> {:ok, noise} = Isotope.Noise.new(%Isotope.Options{seed: 100})
iex> %Isotope.NoiseMap{width: 100, height: 100} = Isotope.Noise.chunk(noise, {0, 0}, 100, 100)

get_noise(noise, axes)

@spec get_noise(noise_ref(), point2d() | point3d()) :: float()

Returns the 2D or 3D noise value depending on axes. If axes is a 2-float tuple, it will return the 2D noise value for the point. If axes is a 3-float tuple, it will return the 3D noise value for the point.

iex> {:ok, noise} = Isotope.Noise.new()
iex> is_float(Isotope.Noise.get_noise(noise, {10.0, 10.0}))
true

iex> {:ok, noise} = Isotope.Noise.new()
iex> is_float(Isotope.Noise.get_noise(noise, {10.0, 10.0, 10.0}))
true

new()

Returns a new noise reference using the default options.

iex> {:ok, _ref} = Isotope.Noise.new()

new(options)

@spec new(options()) :: {:ok, noise_ref()} | {:error, :unsupported_noise}

Returns a new noise reference using the provided options.

iex> {:ok, _ref} = Isotope.Noise.new(%Isotope.Options{seed: 100})

iex> {:error, :unsupported_noise} = Isotope.Noise.new(%Isotope.Options{noise_type: :foobar})

noise_map(noise, size)

@spec noise_map(reference(), size()) :: noisemap()

Generates a 2D noise map of size and returns it.

iex> {:ok, noise} = Isotope.Noise.new()
iex> %Isotope.NoiseMap{width: 20, height: 20} = Isotope.Noise.noise_map(noise, {20, 20})