Structure

CGDataProviderDirectCallbacks

Defines pointers to client-defined callback functions that manage the sending of data for a direct-access data provider.

Declaration

typedef struct CGDataProviderDirectCallbacks {
    ...
} CGDataProviderDirectCallbacks;

Overview

You supply a CGDataProviderDirectCallbacks structure to the function CGDataProviderCreateDirect to create a data provider for direct access. The functions specified by the CGDataProviderDirectCallbacks structure are responsible for copying data a block at a time to a memory buffer for Core Graphics to use. The functions are also responsible for handling the data provider’s basic memory management. For the callback to work, one of the getBytePointer and getBytesAtPosition parameters must be non-NULL. If both are non-NULL, then getBytePointer is used to access the data.

Topics

Instance Properties

getBytePointer

A pointer to a function that returns a pointer to the provider’s data. For more information, see CGDataProviderGetBytePointerCallback.

getBytesAtPosition

A pointer to a function that copies data from the provider.

releaseBytePointer

A pointer to a function that Core Graphics calls to release a pointer to the provider’s data. For more information, see CGDataProviderReleaseBytePointerCallback.

releaseInfo

A pointer to a function that handles clean-up for the data provider, or NULL. For more information, see CGDataProviderReleaseInfoCallback.

version

The version of this structure. It should be set to 0.

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