Harmonica

A simple, efficient spring animation library for smooth, natural motion.

import "github.com/charmbracelet/harmonica"

// A thing we want to animate.
sprite := struct{
    x, xVelocity float64
    y, yVelocity float64
}{}

// Where we want to animate it.
const targetX = 50.0
const targetY = 100.0

// Initialize a spring with framerate, angular frequency, and damping values.
spring := harmonica.NewSpring(harmonica.FPS60, 0.8, 0.98)

// Animate!
for {
    spring.Update(&sprite.x, &sprite.xVelocity, targetX)
    spring.Update(&sprite.y, &sprite.yVelocity, targetY)
    time.Sleep(time.Second/60)
}

For details, see the examples and the docs.

Acknowledgements

This library is a fairly straightforward port of Ryan Juckett’s excellent damped simple harmonic oscillator originally writen in C++ in 2008 and published in 2012. Ryan’s writeup on the subject is fantastic.

License

MIT

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Part of Charm.

Charm热爱开源 • Charm loves open source