Presents the drawable on the screen at a specific host time.
- iOS 8.0+
- macOS 10.11+
- tvOS 9.0+
The Mach absolute time at which the drawable should be presented, in seconds.
Graphics and compute commands can schedule render or write requests to a given drawable. A drawable tracks whether it has outstanding render or write requests on it and will not present until those requests have been completed.
In this case, the drawable attempts to present at a specific host time, but may miss this opportunity if the command buffer has not completed all render or write requests for that drawable. If the given presentation time is missed, then the drawable will present at the next possible opportunity.