react-native-reanimated/lib/module/animation/decay/rubberBandDecay.js

More powerful alternative to Animated library for React Native.

'use strict';

import { SLOPE_FACTOR, VELOCITY_EPS } from "./utils.js";
const DERIVATIVE_EPS = 0.1;
export function rubberBandDecay(animation, now, config) {
  'worklet';

  const {
    lastTimestamp,
    startTimestamp,
    current,
    velocity
  } = animation;
  const deltaTime = Math.min(now - lastTimestamp, 64);
  const clampIndex = Math.abs(current - config.clamp[0]) < Math.abs(current - config.clamp[1]) ? 0 : 1;
  let derivative = 0;
  if (current < config.clamp[0] || current > config.clamp[1]) {
    derivative = current - config.clamp[clampIndex];
  }
  const v = velocity * Math.exp(-(1 - config.deceleration) * (now - startTimestamp) * SLOPE_FACTOR) - derivative * config.rubberBandFactor;
  if (Math.abs(derivative) > DERIVATIVE_EPS) {
    animation.springActive = true;
  } else if (animation.springActive) {
    animation.current = config.clamp[clampIndex];
    return true;
  } else if (Math.abs(v) < VELOCITY_EPS) {
    return true;
  }
  animation.current = current + v * config.velocityFactor * deltaTime / 1000;
  animation.velocity = v;
  animation.lastTimestamp = now;
  return false;
}
//# sourceMappingURL=rubberBandDecay.js.map