@tamagui/react-native-web-lite/src/vendor/react-native/Animated/animations/SpringAnimation.js

React Native for Web

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 */

'use strict'

import { Animation } from './Animation'
import { SpringConfig } from '../SpringConfig'

import { invariant } from '@tamagui/react-native-web-internals'

import { shouldUseNativeDriver } from '../NativeAnimatedHelper'

class SpringAnimation extends Animation {
  _overshootClamping
  _restDisplacementThreshold
  _restSpeedThreshold
  _lastVelocity
  _startPosition
  _lastPosition
  _fromValue
  _toValue
  _stiffness
  _damping
  _mass
  _initialVelocity
  _delay
  _timeout
  _startTime
  _lastTime
  _frameTime
  _onUpdate
  _animationFrame
  _useNativeDriver
  _platformConfig

  constructor(config) {
    super()

    this._overshootClamping = config.overshootClamping ?? false
    this._restDisplacementThreshold = config.restDisplacementThreshold ?? 0.001
    this._restSpeedThreshold = config.restSpeedThreshold ?? 0.001
    this._initialVelocity = config.velocity ?? 0
    this._lastVelocity = config.velocity ?? 0
    this._toValue = config.toValue
    this._delay = config.delay ?? 0
    this._useNativeDriver = shouldUseNativeDriver(config)
    this._platformConfig = config.platformConfig
    this.__isInteraction = config.isInteraction ?? !this._useNativeDriver
    this.__iterations = config.iterations ?? 1

    if (
      config.stiffness !== undefined ||
      config.damping !== undefined ||
      config.mass !== undefined
    ) {
      invariant(
        config.bounciness === undefined &&
          config.speed === undefined &&
          config.tension === undefined &&
          config.friction === undefined,
        'You can define one of bounciness/speed, tension/friction, or stiffness/damping/mass, but not more than one'
      )
      this._stiffness = config.stiffness ?? 100
      this._damping = config.damping ?? 10
      this._mass = config.mass ?? 1
    } else if (config.bounciness !== undefined || config.speed !== undefined) {
      // Convert the origami bounciness/speed values to stiffness/damping
      // We assume mass is 1.
      invariant(
        config.tension === undefined &&
          config.friction === undefined &&
          config.stiffness === undefined &&
          config.damping === undefined &&
          config.mass === undefined,
        'You can define one of bounciness/speed, tension/friction, or stiffness/damping/mass, but not more than one'
      )
      const springConfig = SpringConfig.fromBouncinessAndSpeed(
        config.bounciness ?? 8,
        config.speed ?? 12
      )
      this._stiffness = springConfig.stiffness
      this._damping = springConfig.damping
      this._mass = 1
    } else {
      // Convert the origami tension/friction values to stiffness/damping
      // We assume mass is 1.
      const springConfig = SpringConfig.fromOrigamiTensionAndFriction(
        config.tension ?? 40,
        config.friction ?? 7
      )
      this._stiffness = springConfig.stiffness
      this._damping = springConfig.damping
      this._mass = 1
    }

    invariant(this._stiffness > 0, 'Stiffness value must be greater than 0')
    invariant(this._damping > 0, 'Damping value must be greater than 0')
    invariant(this._mass > 0, 'Mass value must be greater than 0')
  }

  __getNativeAnimationConfig() {
    return {
      type: 'spring',
      overshootClamping: this._overshootClamping,
      restDisplacementThreshold: this._restDisplacementThreshold,
      restSpeedThreshold: this._restSpeedThreshold,
      stiffness: this._stiffness,
      damping: this._damping,
      mass: this._mass,
      initialVelocity: this._initialVelocity ?? this._lastVelocity,
      toValue: this._toValue,
      iterations: this.__iterations,
      platformConfig: this._platformConfig,
    }
  }

  start(fromValue, onUpdate, onEnd, previousAnimation, animatedValue) {
    this.__active = true
    this._startPosition = fromValue
    this._lastPosition = this._startPosition

    this._onUpdate = onUpdate
    this.__onEnd = onEnd
    this._lastTime = Date.now()
    this._frameTime = 0.0

    if (previousAnimation instanceof SpringAnimation) {
      const internalState = previousAnimation.getInternalState()
      this._lastPosition = internalState.lastPosition
      this._lastVelocity = internalState.lastVelocity
      // Set the initial velocity to the last velocity
      this._initialVelocity = this._lastVelocity
      this._lastTime = internalState.lastTime
    }

    const start = () => {
      if (this._useNativeDriver) {
        this.__startNativeAnimation(animatedValue)
      } else {
        this.onUpdate()
      }
    }

    //  If this._delay is more than 0, we start after the timeout.
    if (this._delay) {
      this._timeout = setTimeout(start, this._delay)
    } else {
      start()
    }
  }

  getInternalState() {
    return {
      lastPosition: this._lastPosition,
      lastVelocity: this._lastVelocity,
      lastTime: this._lastTime,
    }
  }

  /**
   * This spring model is based off of a damped harmonic oscillator
   * (https://en.wikipedia.org/wiki/Harmonic_oscillator#Damped_harmonic_oscillator).
   *
   * We use the closed form of the second order differential equation:
   *
   * x'' + (2ζ⍵_0)x' + ⍵^2x = 0
   *
   * where
   *    ⍵_0 = √(k / m) (undamped angular frequency of the oscillator),
   *    ζ = c / 2√mk (damping ratio),
   *    c = damping constant
   *    k = stiffness
   *    m = mass
   *
   * The derivation of the closed form is described in detail here:
   * http://planetmath.org/sites/default/files/texpdf/39745.pdf
   *
   * This algorithm happens to match the algorithm used by CASpringAnimation,
   * a QuartzCore (iOS) API that creates spring animations.
   */
  onUpdate() {
    // If for some reason we lost a lot of frames (e.g. process large payload or
    // stopped in the debugger), we only advance by 4 frames worth of
    // computation and will continue on the next frame. It's better to have it
    // running at faster speed than jumping to the end.
    const MAX_STEPS = 64
    let now = Date.now()
    if (now > this._lastTime + MAX_STEPS) {
      now = this._lastTime + MAX_STEPS
    }

    const deltaTime = (now - this._lastTime) / 1000
    this._frameTime += deltaTime

    const c = this._damping
    const m = this._mass
    const k = this._stiffness
    const v0 = -this._initialVelocity

    const zeta = c / (2 * Math.sqrt(k * m)) // damping ratio
    const omega0 = Math.sqrt(k / m) // undamped angular frequency of the oscillator (rad/ms)
    const omega1 = omega0 * Math.sqrt(1.0 - zeta * zeta) // exponential decay
    const x0 = this._toValue - this._startPosition // calculate the oscillation from x0 = 1 to x = 0

    let position = 0.0
    let velocity = 0.0
    const t = this._frameTime
    if (zeta < 1) {
      // Under damped
      const envelope = Math.exp(-zeta * omega0 * t)
      position =
        this._toValue -
        envelope *
          (((v0 + zeta * omega0 * x0) / omega1) * Math.sin(omega1 * t) +
            x0 * Math.cos(omega1 * t))
      // This looks crazy -- it's actually just the derivative of the
      // oscillation function
      velocity =
        zeta *
          omega0 *
          envelope *
          ((Math.sin(omega1 * t) * (v0 + zeta * omega0 * x0)) / omega1 +
            x0 * Math.cos(omega1 * t)) -
        envelope *
          (Math.cos(omega1 * t) * (v0 + zeta * omega0 * x0) -
            omega1 * x0 * Math.sin(omega1 * t))
    } else {
      // Critically damped
      const envelope = Math.exp(-omega0 * t)
      position = this._toValue - envelope * (x0 + (v0 + omega0 * x0) * t)
      velocity = envelope * (v0 * (t * omega0 - 1) + t * x0 * (omega0 * omega0))
    }

    this._lastTime = now
    this._lastPosition = position
    this._lastVelocity = velocity

    this._onUpdate(position)
    if (!this.__active) {
      // a listener might have stopped us in _onUpdate
      return
    }

    // Conditions for stopping the spring animation
    let isOvershooting = false
    if (this._overshootClamping && this._stiffness !== 0) {
      if (this._startPosition < this._toValue) {
        isOvershooting = position > this._toValue
      } else {
        isOvershooting = position < this._toValue
      }
    }
    const isVelocity = Math.abs(velocity) <= this._restSpeedThreshold
    let isDisplacement = true
    if (this._stiffness !== 0) {
      isDisplacement =
        Math.abs(this._toValue - position) <= this._restDisplacementThreshold
    }

    if (isOvershooting || (isVelocity && isDisplacement)) {
      if (this._stiffness !== 0) {
        // Ensure that we end up with a round value
        this._lastPosition = this._toValue
        this._lastVelocity = 0
        this._onUpdate(this._toValue)
      }

      this.__debouncedOnEnd({ finished: true })
      return
    }
    // $FlowFixMe[method-unbinding] added when improving typing for this parameters
    this._animationFrame = requestAnimationFrame(this.onUpdate.bind(this))
  }

  stop() {
    super.stop()
    this.__active = false
    clearTimeout(this._timeout)
    global.cancelAnimationFrame(this._animationFrame)
    this.__debouncedOnEnd({ finished: false })
  }
}

export { SpringAnimation }
export default SpringAnimation