Animations

[0HyperCube]

Since there was no issue open
Previously discussed in #1601.
A partial implementation in #1766.
Set as a Google Summer of Code: https://graphite.rs/volunteer/guide/student-projects/#animation-system

Avoiding constant folding - #2232

This work was stalled because of the constant folding: non-async secondary inputs are all evaluated as the graph is compiled. However this is now solved as part of #2232.

First steps - #2443

• Allow the time from the context to be retrieved by the user in the node graph.
• Add simple keybinds for pausing and playing the animation.

Polishing and further work

• Create system for different types of easing.
• Create & implement the timeline UI. Properties for keyframing are added from the properties panel (?).
• Automatic keyframing?
• 2D rigging.
• Frame-by-frame animations (probably with onion skinning to see the previous frame)

Concept by Keavon