56 lines
941 B
Go
56 lines
941 B
Go
package main
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import (
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"image"
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"image/color"
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"image/gif"
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"io"
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"math"
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"math/rand"
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"os"
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"time"
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)
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var palette = []color.Color{color.Black,
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color.RGBA{G: 0xff, A: 0xff}}
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const (
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whiteIndex = 0
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blackIndex = 1
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)
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func main() {
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rand.Seed(time.Now().UTC().UnixNano())
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lissajous(os.Stdout)
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}
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func lissajous(out io.Writer) {
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const (
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cycles = 5
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res = 0.001
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size = 100
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nframes = 64
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delay = 8
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)
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freq := rand.Float64() * 3.0
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anim := gif.GIF{LoopCount: nframes}
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phase := 0.0
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for i := 0; i < nframes; i++ {
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rect := image.Rect(0, 0,
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2*size+1, 2*size+1)
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img := image.NewPaletted(rect, palette)
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for t := 0.0; t < cycles*2*math.Pi; t += res {
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x := math.Sin(t)
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y := math.Sin(t*freq + phase)
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img.SetColorIndex(size+int(x*size+0.5),
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size+int(y*size+0.5), blackIndex)
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}
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phase += 0.1
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anim.Delay = append(anim.Delay, delay)
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anim.Image = append(anim.Image, img)
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}
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gif.EncodeAll(out, &anim)
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}
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