Golang : Create new color from command line parameters

Problem:

You want to create a new color base on given RGBA parameters/arguments from command line. How to do that?

Solution:

Create a new color variable with image/color package. Set the RGBA values with {}, such as:

 color1 := color.RGBA{uint8(red1), uint8(green1), uint8(blue1), uint8(alpha1)}

Here you go!

createnewcolor.go

 package main

 import (
  "fmt"
  "image/color"
  "os"
  "strconv"
 )

 func main() {
  if len(os.Args) != 9 {
 fmt.Printf("Usage : %s <red1> <green1> <blue1> <alpha1> <red2> <green2> <blue2> <alpha1> \n", os.Args[0])
 os.Exit(0)
  }

  //sanity checks
  red1int, _ := strconv.Atoi(os.Args[1])
  red1 := uint8(red1int)

  green1int, _ := strconv.Atoi(os.Args[2])
  green1 := uint8(green1int)

  blue1int, _ := strconv.Atoi(os.Args[3])
  blue1 := uint8(blue1int)

  alpha1int, _ := strconv.Atoi(os.Args[4])
  alpha1 := uint8(alpha1int)

  red2int, _ := strconv.Atoi(os.Args[5])
  red2 := uint8(red2int)

  green2int, _ := strconv.Atoi(os.Args[6])
  green2 := uint8(green2int)

  blue2int, _ := strconv.Atoi(os.Args[7])
  blue2 := uint8(blue2int)

  alpha2int, _ := strconv.Atoi(os.Args[8])
  alpha2 := uint8(alpha2int)

  fmt.Println("Red 1 : ", red1)
  fmt.Println("Green 1 : ", green1)
  fmt.Println("Blue 1 : ", blue1)
  fmt.Println("Alpha 1 : ", alpha1)

  fmt.Println("Red 2 : ", red2)
  fmt.Println("Green 2 : ", green2)
  fmt.Println("Blue 2 : ", blue2)
  fmt.Println("Alpha 2 : ", alpha2)

  // create new colors from given arguments/command line parameters
  color1 := color.RGBA{uint8(red1), uint8(green1), uint8(blue1), uint8(alpha1)}
  color2 := color.RGBA{uint8(red2), uint8(green2), uint8(blue2), uint8(alpha2)}

  fmt.Println("Color 1 = ", color1) // white
  fmt.Println("Color 2 = ", color2) // black
 }

Output:

./createnewcolor 0 0 0 0 0 0 255 0

Red 1 : 0

Green 1 : 0

Blue 1 : 0

Alpha 1 : 0

Red 2 : 0

Green 2 : 0

Blue 2 : 255

Alpha 2 : 0

Color 1 = {0 0 0 0}

Color 2 = {0 0 255 0}

Happy coloring!

Reference:

https://www.socketloop.com/references/golang-image-nrgba-and-nrgba64-set-and-setnrgba-64-functions-example

https://golang.org/pkg/image/color/#Color