NAME

Noise::Simplex – 2-D & 3-D Simplex-noise generator for Raku

SYNOPSIS

```raku use Noise::Simplex;

# 2-D field my $s = Simplex.new(seed => 42); my &n2d = $s.create-noise2d; say &n2d(12.3, 9.8); # → value ≈ [-1,1]

# 3-D slice (z = 0.5) my &n3d = $s.create-noise3d; say &n3d(1.0, 2.0, 0.5); ```

DESCRIPTION

Simplex noise (Gustavson/Perlin) is a coherent, rotation-invariant alternative to classic Perlin noise. This module delivers pure-Raku 2-D and 3-D fields seeded by a 64-bit Mersenne-Twister PRNG.

CLASS

Simplex

=over 4

• C\<new(:\$seed!)>

Create a generator initialised with an integer seed. Different seeds produce independent noise fields.

• create-noise2d → Callable

Returns a two-argument callable C\<sub (\$x, \$y --> Numeric)> that evaluates the 2-D field.

• create-noise3d → Callable

Returns a three-argument callable C\<sub (\$x, \$y, \$z --> Numeric)> that evaluates the 3-D field.

=back

RANGE

Outputs are centred on zero and scaled to roughly \[-1,1] using factors 70 (2-D) and 32 (3-D).

EXAMPLE – quick greyscale PNG

```raku #!/usr/bin/env raku

use lib 'lib'; use Noise::Simplex; use Image::PNG::Portable;

# Set width/height for noise image. my $width = 512; my $height = 512;

# Create a new Noise::Simplex with seed 12345, then return a 2D noise map. my $simplex = Simplex.new(seed => 12345); my &noise2d = $simplex.create-noise2d;

# Set up a PNG image of width $width & height $height # Note: requires Image::PNG::Portable to be installed. my $img = Image::PNG::Portable.new: :$width, :$height, :alpha(False);

# For each x,y value for 0 ..^ $height -> $y { for 0 ..^ $width -> $x { # Sample the noise at x/y (divide by 64 for very smooth noise). my $n = noise2d($x / 64, $y / 64); # Add 1 and multiply by 127.5 to get a value between 0 & 255 (RGB) my $val = ($n + 1) * 127.5; # Set the pixel value of the image to our value derived above. $img.set: $x, $y, $val.round, $val.round, $val.round; } }

# Save the image in img/2d.png. $img.write: "img/2d.png"; ```

AUTHOR

Matt Doughty

LICENSE

Artistic 2.0