"toggled"
Only signal a change if the user made one. Toggled would be signalled even when
we set it programmatically (e.g. by simply creating the checkbox widget and
setting its state) causing unnecessary re-caches of the sequence.
Previously, FFmpeg decoders needed to wait for the initial index to finish
before they could retrieve frames. Now they can retrieve frames while the
index is occurring, provided the appropriate frame has already been indexed (if
not, the retrieve will need to wait still).
Our renderer system is already heavily multithreaded and prioritized to keep the
main thread active. As a result, FFmpeg receives little benefits from being
multithreaded and is actually detrimental to our main thread as it hasn't been
prioritized to keep the main thread as active as possible.
Cuts down on a lot of duplicate code between
TimelineWidget/ViewerWidget/CurveWidget/NodeParamView
and TimelinePanel/ViewerPanel/CurvePanel/ParamPanel since they all use similar
time functions.
When dragging a value in the UI, we use a "single frame update" because we want
to prioritize the currently visible frame to give visual feedback as soon as
possible. Previously, we generated a single frame InvalidateCache() signal
from the widgets themselves, but this had the major downside of not necessarily
emitting the time that the viewer was actually showing (due to either node time
transformations or times differing between the effects panels and the viewer
panels). Now, we send a different signal that viewers can handle themselves to
update the time that they're currently showing. This means the fast updating
will work no matter how many viewers are connected at whatever time each viewer
is set to.
itsmattkc