flush_ext

Description:

public void flush_ext (Rectangle rect)

Invokes the external flush function, if any is set on the provided buffer - this ensures that data pending - in the current implementation only OpenCL - externally to be synchronized with the buffer.

Multi threaded code should call such a synchronization before branching out to avoid each of the threads having an implicit synchronization of its own.

Parameters:

this	a GeglBuffer
rect	rectangle