sprung

Sprung is an easy-to-consume Curve that uses real physics equations to drive your animations.

Easy to consume

AnimatedContainer(
  curve: Sprung(),
  /// ...
),

Sprung() also supports three damping curves, Damped.under, Damped.critically, and Damped.over.

AnimatedContainer(
  curve: Sprung(
    damped: Damped.under
  ),
  /// ...
),

Note: Sprung is critically damped by default.

Based on Physics

Using Newton's Second Law of Motion, Hooke's Law, and velocity based damping, we implement the following equation in three finite cases.

m times x dot dot equals negative k times parenthesis x minus 1 close parenthesis minus c times x dot

Believable motion

demo of under, critically, and over damped Flutter curves

Reliable accuracy

Sprung exceeds Flutter specifications for curves by guaranteeing an error less than 1e-6. This amounts to a 0.0019px jitter at the beginning or end of a 1920px move.

Prior Art

https://medium.com/@dtinth/spring-animation-in-css-2039de6e1a03

Libraries

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sprung

Dart

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