go制作gif动画

Posted 2020-08-28 Reve_wang

今天看了golang中国社区翻译的"go语言圣经"，在第一章1.4节讲到用go制作gif动画，感觉非常有意思，分享给大家

package main

import (

    "image"

    "image/color"

    "image/gif"

    "io"

    "math"

    "math/rand"

    "os"

)

var palette = []color.Color{color.White, color.Black} //调色板

const (

    whiteIndex = 0

    blackIndex = 1

)

func main() {

    lissajous(os.Stdout)

}

func lissajous(out io.Writer) {

    const (

        cycles  = 5

        res     = 0.001

        size    = 100

        nframes = 64

        delay   = 8

    )

    freq := rand.Float64() * 3.0

    anim := gif.GIF{LoopCount: nframes}

    phase := 0.0

    for i := 0; i < nframes; i++ {

        rect := image.Rect(0, 0, 2*size+1, 2*size+1)

        img := image.NewPaletted(rect, palette)

        for t := 0.0; t < cycles*2*math.Pi; t += res {

            x := math.Sin(t)

            y := math.Sin(t*freq + phase)

            img.SetColorIndex(size+int(x*size+0.5), size+int(y*size+0.5), blackIndex)

        }

        phase += 0.1

        anim.Delay = append(anim.Delay, delay)

        anim.Image = append(anim.Image, img)

    }

    gif.EncodeAll(out, &anim)

}

$ go build gif.go 
$ ./gif >out.gif