Poster IDs

Boards such as /pol/ and /bant/ support unique poster IDs that let you recognize the individual behind posts throughout a thread.

These IDs are displayed with colors on 4chan but colorless on FoolFuuka. We've been able to locate the code computing the color within 4chan's JS extension and offer a simplified Golang version below:

func IDStyle(s string) string { //Initially equals 0 var hash int64

//Iterate over bytes in the string for _, r := range []byte(s) { hash = ((hash << 5) - hash) + int64(r) }

red := (hash >> 24) & 0xFF green := (hash >> 16) & 0xFF blue := (hash >> 8) & 0xFF

result := fmt.Sprintf("background-color: rgb(%d, %d, %d);", red, green, blue)

//Determines how light the color just computed is     light := float64(red)*0.299+float64(green)*0.587+float64(blue)*0.114 > 125

if light { result += "color: black;" } else { result += "color: white;" }

//e.g. "background-color: rbg(10, 20, 30); color: white;" return result } = See also =
 * Thread about the exact probability of getting k0t ID and other funny short strings : https://mathchan.org/math/thread/106