A callback function that copies from a provider data stream into a Core Graphics buffer.
- iOS 2.0+
- macOS 10.3+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 2.0+
- Core Graphics
A generic pointer to private data shared among your callback functions. This is the same pointer you supplied to
The Core Graphics buffer into 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 buffer, you should return