struct SimplexNoise2D

Structure

SimplexNoise2D

A type of two-dimensional gradient noise (sometimes called Perlin noise), suitable for texturing two-dimensional planes. Simplex noise was originally an open-source improvement on the classical Perlin gradient noise algorithm, and thus is often referred to as OpenSimplex noise, to distinguish it from a patented variant of simplex noise. Simplex noise is supported in the library mainly because it has historical significance; it has since been superseded by the less popular, but more powerful and more efficient super-simplex noise.

In almost all cases, super-simplex noise should be preferred.

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Symbols

Initializers

init(amplitude:Double, frequency:Double, seed:Int = 0)

Creates an instance with the given amplitude, frequency, and random seed values. Creating an instance generates a new pseudo-random permutation table for that instance, and a new instance does not need to be regenerated to sample the same procedural noise field.

The given amplitude is adjusted internally to produce output approximately within the range of -amplitude ... amplitude, however this is not strictly guaranteed.

Instance methods

func evaluate(_ x:Double, _ y:Double) -> Double

Evaluates the simplex noise field at the given coordinates.

func evaluate(_ x:Double, _ y:Double, _:Double) -> Double

Evaluates the simplex noise field at the given coordinates. The third coordinate is ignored.

func evaluate(_ x:Double, _ y:Double, _:Double, _:Double) -> Double

Evaluates the simplex noise field at the given coordinates. The third and fourth coordinates are ignored.

func sample_area(width:Int, height:Int) -> [(Double, Double, Double)]

Evaluates the noise field over the given area, starting from the origin, and extending over the first quadrant, taking unit steps in both directions. Although the x and y coordinates are returned, the output vector is guaranteed to be in row-major order.

func sample_area_saturated_to_u8(width:Int, height:Int, offset:Double = 0.5) -> [UInt8]

Evaluates the noise field over the given area, starting from the origin, and extending over the first quadrant, storing the values in a row-major array of samples. The samples are clamped, but not scaled, to the range 0 ... 255.

func sample_volume(width:Int, height:Int, depth:Int) -> [(Double, Double, Double, Double)]

Evaluates the noise field over the given volume, starting from the origin, and extending over the first octant, taking unit steps in all three directions. Although the x, y, and z coordinates are returned, the output vector is guaranteed to be in xy-plane-major, and then row-major order.

func sample_volume_saturated_to_u8(width:Int, height:Int, depth:Int, offset:Double = 0.5) -> [UInt8]

Evaluates the noise field over the given volume, starting from the origin, and extending over the first octant, storing the values in a xy-plane-major, and then row-major order array of samples. The samples are clamped, but not scaled, to the range 0 ... 255.

Relationships

Conforms to

Noise