createCGLayer(with:info:)
Creates a CGLayer object from the provided parameters.
Declaration
func createCGLayer(with size: CGSize, info: CFDictionary?) -> CGLayer?Parameters
- size:
The size, in default user space units, of the layer relative to the graphics context.
- info:
A dictionary, which is passed to
CGLayerCreateWithContextas theauxiliaryInfoparameter. PassNULLbecause this parameter is reserved for future use.
Return Value
A CGLayer object.
Discussion
After calling this method, Core Image draws content into the CGLayer object. Core Image creates a CGLayer object by calling the Quartz 2D function init(_:size:auxiliaryInfo:), whose prototype is:
CGLayerRef CGLayerCreateWithContext (
CGContextRef context,
CGSize size,
CFDictionaryRef auxiliaryInfo
);Core Image passes the CIContext object as the context parameter, the size as the size parameter, and the dictionary as the auxiliaryInfo parameter. For more information on CGLayer objects, see Quartz 2D Programming Guide and CGLayer.