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Generate Animation GIF with Golang
package main
import (
"fmt"
"image"
"image/color"
"image/gif"
"math"
"os"
)
type Circle struct {
X, Y, R float64
}
func (c *Circle) Brightness(x, y float64) uint8 {
var dx, dy float64 = c.X - x, c.Y - y
d := math.Sqrt(dx*dx+dy*dy) / c.R
if d > 1 {
return 0
} else {
return 255
}
}
func main() {
var w, h int = 240, 240
var palette = []color.Color{
color.RGBA{0x00, 0x00, 0x00, 0xff}, color.RGBA{0x00, 0x00, 0xff, 0xff},
color.RGBA{0x00, 0xff, 0x00, 0xff}, color.RGBA{0x00, 0xff, 0xff, 0xff},
color.RGBA{0xff, 0x00, 0x00, 0xff}, color.RGBA{0xff, 0x00, 0xff, 0xff},
color.RGBA{0xff, 0xff, 0x00, 0xff}, color.RGBA{0xff, 0xff, 0xff, 0xff},
}
var images []*image.Paletted
var delays []int
var hw, hh float64 = float64(w / 2), float64(h / 2)
circles := []*Circle{&Circle{}, &Circle{}, &Circle{}}
steps := 20
for step := 0; step < steps; step++ {
img := image.NewPaletted(image.Rect(0, 0, w, h), palette)
images = append(images, img)
delays = append(delays, 0)
θ := 2.0 * math.Pi / float64(steps) * float64(step)
for i, circle := range circles {
θ0 := 2 * math.Pi / 3 * float64(i)
circle.X = hw - 40*math.Sin(θ0) - 20*math.Sin(θ0+θ)
circle.Y = hh - 40*math.Cos(θ0) - 20*math.Cos(θ0+θ)
circle.R = 50
}
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
img.Set(x, y, color.RGBA{
circles[0].Brightness(float64(x), float64(y)),
circles[1].Brightness(float64(x), float64(y)),
circles[2].Brightness(float64(x), float64(y)),
255,
})
}
}
}
f, err := os.OpenFile("rgb.gif", os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
fmt.Println(err)
return
}
defer f.Close()
gif.EncodeAll(f, &gif.GIF{
Image: images,
Delay: delays,
})
}
@nitoyon
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Author

nitoyon commented Jan 1, 2016

Result
rgb

@stdkraken
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Wow. That's such amazing.

@bvp
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bvp commented Sep 15, 2022

awesome

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