Copies data from a Core Graphics-supplied buffer into a data consumer.
- iOS 2.0+
- macOS 10.4+
- tvOS 9.0+
- watchOS 2.0+
- Core Graphics
A generic pointer to private data shared among your callback functions. This is the pointer supplied to
The buffer from which you copy the specified number of bytes.
The number of bytes to copy.
The number of bytes copied. If no more data can be written to the consumer, you should return
When Core Graphics is ready to send data to the consumer, your function is called. It should copy the specified number of bytes from
buffer into some resource under your control—for example, a file.