protocol Noise

Protocol

Noise

A procedural noise generator.

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Symbols

Initializers

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

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.

Instance methods

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

Evaluates the noise field at the given coordinate. For three-dimensional and higher noise fields, the z and w coordinates, if applicable, are set to zero.

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

Evaluates the noise field at the given coordinate. For two-dimensional noise fields, the z coordinate is ignored. For four-dimensional noise fields, the w coordinate is set to zero.

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

Evaluates the noise field at the given coordinate. For three-dimensional and lower noise fields, the z and w coordinates are ignored, if necessary. No existing noise generator in the library currently supports true four-dimensional evaluation.

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.