Interpolator

An interpolator: eases keyframes, state transitions, layout animations and interpolating data converters.

Rive creates an instance per owner instance: each playing animation gets one per keyframe, each state machine one per interpolator its transitions use, each artboard one per interpolator its layout styles use, and each bound converter its own. Transitions or layout styles that use the same interpolator share its instance, as do layouts that inherit their animation from a parent layout (including nested artboards and list items).

So transform and transformValue can be called many times per frame, by several layouts, in any order. Compute the result from value (and from and to), the inputs and whatever init set up; don’t keep progress in self between calls.

Methods

init

init(self: T, context: Context) -> boolean

transform

transform(self: T, value: number) -> number

Maps a linear progress value in 0..1 to an eased one.

transformValue

transformValue(self: T, from: number, to: number, value: number) -> number

Returns the value between from and to at linear progress value.