Identifiers that are passed to CoglFrameCallback functions
(registered using Onscreen::add_frame_callback) that
mark the progression of a frame in some way which usually
means that new information will have been accumulated in the
frame’s corresponding FrameInfo object.
The last event that will be sent for a frame will be a
FrameEvent::Complete event and so these are a good
opportunity to collect statistics about a frame since the
FrameInfo should hold the most data at this point.
<note>A frame may not be completed before the next frame can start
so applications should avoid needing to collect all statistics for
a particular frame before they can start a new frame.</note>
Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.
Notifies that a frame has ended. This
is a good time for applications to
collect statistics about the frame
since the FrameInfo should hold
the most data at this point. No other
events should be expected after a
FrameEvent::Complete event.