rbgをhexに相互変換する。golang

main.go

package main

import "fmt"

func main() {
	fmt.Println(dec2hex(256, 4))
	fmt.Println(rgb2int(256, 256, 256))
	fmt.Println(int2rgb(0))
}

func dec2hex(n, beam int) string {
	hex := ""
	str := "0123456789abcdef"
	for i := 0; i < beam; i++ {
		m := n & 0xf
		hex = string(str[m]) + hex
		n -= m
		n >>= 4
	}
	return hex
}

func rgb2int(r, g, b int) int {
	return (((r >> 5) << 6) | ((g >> 5) << 3) | ((b >> 5) << 0))
}

func int2rgb(i int) (r, g, b int) {
	return ((i >> 6 & 0x7) << 5) + 16, ((i >> 3 & 0x7) << 5) + 16, ((i >> 0 & 0x7) << 5) + 16
}