wrp/util.go

90 lines
2.6 KiB
Go
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2024-07-09 04:27:51 +00:00
// wrp utility functions
package main
import (
"image"
"image/color/palette"
"log"
"net"
"strings"
"github.com/MaxHalford/halfgone"
"github.com/soniakeys/quant/median"
)
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func printMyIPs(b string) {
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ap := strings.Split(b, ":")
if len(ap) < 1 {
log.Fatal("Wrong format of ipaddress:port")
}
log.Printf("Listen address: %v", b)
if ap[0] != "" && ap[0] != "0.0.0.0" {
return
}
a, err := net.InterfaceAddrs()
if err != nil {
log.Print("Unable to get interfaces: ", err)
return
}
var m string
for _, i := range a {
n, ok := i.(*net.IPNet)
if !ok || n.IP.IsLoopback() || strings.Contains(n.IP.String(), ":") {
continue
}
m = m + n.IP.String() + " "
}
log.Print("My IP addresses: ", m)
}
func gifPalette(i image.Image, n int64) image.Image {
switch n {
case 2:
i = halfgone.FloydSteinbergDitherer{}.Apply(halfgone.ImageToGray(i))
case 216:
var FastGifLut = [256]int{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5}
r := i.Bounds()
// NOTE: the color index computation below works only for palette.WebSafe!
p := image.NewPaletted(r, palette.WebSafe)
if i64, ok := i.(image.RGBA64Image); ok {
for y := r.Min.Y; y < r.Max.Y; y++ {
for x := r.Min.X; x < r.Max.X; x++ {
c := i64.RGBA64At(x, y)
r6 := FastGifLut[c.R>>8]
g6 := FastGifLut[c.G>>8]
b6 := FastGifLut[c.B>>8]
p.SetColorIndex(x, y, uint8(36*r6+6*g6+b6))
}
}
} else {
for y := r.Min.Y; y < r.Max.Y; y++ {
for x := r.Min.X; x < r.Max.X; x++ {
c := i.At(x, y)
r, g, b, _ := c.RGBA()
r6 := FastGifLut[r&0xff]
g6 := FastGifLut[g&0xff]
b6 := FastGifLut[b&0xff]
p.SetColorIndex(x, y, uint8(36*r6+6*g6+b6))
}
}
}
i = p
default:
q := median.Quantizer(n)
i = q.Paletted(i)
}
return i
}
func asciify(s []byte) []byte {
a := make([]byte, len(s))
for i := 0; i < len(s); i++ {
if s[i] > 127 {
a[i] = '.'
continue
}
a[i] = s[i]
}
return a
}