Function setSprings

packages/core/src/Controller.ts:539–549

(
  ctrl: Controller<Lookup<any>>,
  springs: SpringValues<UnknownProps>
)

 * whose key is not already in use.
 */
export function setSprings(
  ctrl: Controller<Lookup<any>>,
  springs: SpringValues<UnknownProps>
) {
  eachProp(springs, (spring, key) => {
    if (!ctrl.springs[key]) {
      ctrl.springs[key] = spring
      addFluidObserver(spring, ctrl)
    }
  })
}

function createSpring(key: string, observer?: FluidObserver<FrameValue.Event>) {
  const spring = new SpringValue()