Type Alias

CVDisplayLinkOutputCallback

Defines a pointer to a display link output callback function, which is called whenever the display link wants the application to output a frame.

Declaration

Parameters

displayLink

The display link requesting the frame.

inNow

A pointer to the current time.

inOutputTime

A pointer to the time that the frame will be displayed.

flagsIn

Currently unused. Pass 0.

flagsOut

Currently unused. Pass 0.

displayLinkContext

A pointer to application-defined data. This is the pointer you passed into the CVDisplayLinkOutputCallback function when registering your callback.

Discussion

For a given display link, you must register a display link output callback using CVDisplayLinkOutputCallback so that you can process and output the requested frame.

Your callback must retrieve the frame with the timestamp specified by the (inOutputTime parameter, manipulate it if desired (for example, apply color correction or map into onto a surface), and then output it to the display.