Creates a Core Graphics function.


init?(info: UnsafeMutableRawPointer?, domainDimension: Int, domain: UnsafePointer<CGFloat>?, rangeDimension: Int, range: UnsafePointer<CGFloat>?, callbacks: UnsafePointer<CGFunctionCallbacks>)



A pointer to user-defined storage for data that you want to pass to your callbacks. You need to make sure that the data persists for as long as it’s needed, which can be beyond the scope in which the Core Graphics function is used.


The number of inputs.


An array of (2*domainDimension) floats used to specify the valid intervals of input values. For each k from 0 to (domainDimension - 1), domain[2*k] must be less than or equal to domain[2*k+1], and the kth input value will be clipped to lie in the interval domain[2*k] ≤ input[k] ≤ domain[2*k+1]. If this parameter is NULL, then the input values are not clipped.


The number of outputs.


An array of (2*rangeDimension) floats that specifies the valid intervals of output values. For each k from 0 to (rangeDimension - 1), range[2*k] must be less than or equal to range[2*k+1], and the kth output value will be clipped to lie in the interval range[2*k] ≤ output[k] ≤ range[2*k+1]. If this parameter is NULL, then the output values are not clipped.


A pointer to a callback function table. This table should contain pointers to the callbacks you provide to implement the semantics of this Core Graphics function. Core Graphics makes a copy of your table, so, for example, you could safely pass in a pointer to a structure on the stack.

Return Value

The new Core Graphics function. You are responsible for releasing this object using CGFunctionRelease.

See Also

Creating Function Objects

struct CGFunctionCallbacks

A structure that contains callbacks needed by a CGFunctionRef object.

typealias CGFunctionEvaluateCallback

Performs custom operations on the supplied input data to produce output data.

typealias CGFunctionReleaseInfoCallback

Performs custom clean-up tasks when Core Graphics deallocates a CGFunctionRef object.