"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.
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.
This adds the ability to keyframe more than one value per input (e.g. a vec2,
vec3, etc.) so that you can animate, for example, an X axis separately from a
Y axis.
Widget now supports creating keyframe and standard values, supports dragging
from sliders (not creating an undo command for each drag), and everything is
undoable.
Previously the non-keyframed value was stored as a static keyframe but this
introduced issues when an input was in a state of keyframes being enabled but
0 keyframes existing. Having a standard value makes much more sense.
The new rendering pipeline strives to simplify the nodes themselves as much
as possible and move much of the logic to an external rendering engine. This
change removes all of the responsibilities that no longer belong to the
nodes themselves and will soon be folded into the renderer.
Nodes were previously written to be "strongly typed" in that a parameter's
"type" enforced whether it could be connected to another. All code related
to that has now been removed since not only is it hard to maintain and
likely unnecessary, it's possible the nodes will work differently later on
anyway.
itsmattkc