-
Notifications
You must be signed in to change notification settings - Fork 0
/
lissajous.go
61 lines (56 loc) · 1.43 KB
/
lissajous.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
package main
import (
"image"
"image/color"
"image/gif"
"io"
"log"
"math"
"math/rand"
"net/http"
"os"
"strconv"
"time"
)
var palette = []color.Color{color.White, color.Black}
const (
whiteIndex = 0 //画板中第一种验收
blackIndex = 1 //画板中第二种颜色
)
func main() {
rand.Seed(time.Now().UTC().UnixNano())
if len(os.Args) > 1 && os.Args[1] == "web" {
handler := func(w http.ResponseWriter, r *http.Request) {
cycles, _ := strconv.Atoi(r.FormValue("cycles"))
lissajous(w, cycles)
}
http.HandleFunc("/", handler)
log.Fatal(http.ListenAndServe("localhost:8000", nil))
return
}
lissajous(os.Stdout, 20)
}
func lissajous(out io.Writer, cycles int) {
const (
res = 0.001 // 角度分辨率
size = 100 // 图像画布包含[-size..+size]
nframes = 64 // 动画中的帧数
delay = 8 // 以10ms为单位的帧间延迟
)
freq := rand.Float64() * 3.0 //y振荡器的相对频率
anim := gif.GIF{LoopCount: nframes}
phase := 0.0 //phase difference
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 < float64(cycles)*2*math.Pi; t += res {
x := math.Sinh(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)
}