---
title: "FloatAnimationSpec"
description: "[FloatAnimationSpec] interface is similar to [VectorizedAnimationSpec], except it deals
exclusively with floats.

Like [VectorizedAnimationSpec], [FloatAnimationSpec] is entirely stateless as well. It requires
start/end values and start velocity to be passed in for the query of velocity and value of the
animation. The [FloatAnimationSpec] itself stores only the animation configuration (such as the
delay, duration and easing curve for [FloatTweenSpec], or spring constants for [FloatSpringSpec].

A [FloatAnimationSpec] can be converted to an [VectorizedAnimationSpec] using [vectorize]."
type: "interface"
---

<div class='type'>Interface</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>



```kotlin
@JvmDefaultWithCompatibility
public interface FloatAnimationSpec : AnimationSpec<Float>
```


`FloatAnimationSpec` interface is similar to `VectorizedAnimationSpec`, except it deals
exclusively with floats.

Like `VectorizedAnimationSpec`, `FloatAnimationSpec` is entirely stateless as well. It requires
start/end values and start velocity to be passed in for the query of velocity and value of the
animation. The `FloatAnimationSpec` itself stores only the animation configuration (such as the
delay, duration and easing curve for `FloatTweenSpec`, or spring constants for `FloatSpringSpec`.

A `FloatAnimationSpec` can be converted to an `VectorizedAnimationSpec` using `vectorize`.


## Functions

```kotlin
public fun getValueFromNanos(
        playTimeNanos: Long,
        initialValue: Float,
        targetValue: Float,
        initialVelocity: Float,
    ): Float
```


Calculates the value of the animation at given the playtime, with the provided start/end
values, and start velocity.

#### Parameters

| | |
| --- | --- |
| playTimeNanos | time since the start of the animation |
| initialValue | start value of the animation |
| targetValue | end value of the animation |
| initialVelocity | start velocity of the animation |



```kotlin
public fun getVelocityFromNanos(
        playTimeNanos: Long,
        initialValue: Float,
        targetValue: Float,
        initialVelocity: Float,
    ): Float
```


Calculates the velocity of the animation at given the playtime, with the provided start/end
values, and start velocity.

#### Parameters

| | |
| --- | --- |
| playTimeNanos | time since the start of the animation |
| initialValue | start value of the animation |
| targetValue | end value of the animation |
| initialVelocity | start velocity of the animation |



```kotlin
public fun getEndVelocity(
        initialValue: Float,
        targetValue: Float,
        initialVelocity: Float,
    ): Float
```


Calculates the end velocity of the animation with the provided start/end values, and start
velocity. For duration-based animations, end velocity will be the velocity of the animation
at the duration time. This is also the default assumption. However, for spring animations,
the transient trailing velocity will be snapped to zero.

#### Parameters

| | |
| --- | --- |
| initialValue | start value of the animation |
| targetValue | end value of the animation |
| initialVelocity | start velocity of the animation |



```kotlin
public fun getDurationNanos(
        initialValue: Float,
        targetValue: Float,
        initialVelocity: Float,
    ): Long
```


Calculates the duration of an animation. For duration-based animations, this will return the
pre-defined duration. For physics-based animations, the duration will be estimated based on
the physics configuration (such as spring stiffness, damping ratio, visibility threshold) as
well as the `initialValue`, `targetValue` values, and `initialVelocity`.

__Note__: this may be a computation that is expensive - especially with spring based
animations

#### Parameters

| | |
| --- | --- |
| initialValue | start value of the animation |
| targetValue | end value of the animation |
| initialVelocity | start velocity of the animation |



```kotlin
override fun <V : AnimationVector> vectorize(
        converter: TwoWayConverter<Float, V>
    ): VectorizedFloatAnimationSpec<V>
```


Create an `VectorizedAnimationSpec` that animates `AnimationVector` from a
`FloatAnimationSpec`. Every dimension of the `AnimationVector` will be animated using the
given `FloatAnimationSpec`.