status-im/status-go

package identicon

import (
    "bytes"
    "encoding/base64"
    "image"
    "image/color"
    "image/draw"
    "image/png"
)

const (
    Width  = 50
    Height = 50
)

func renderBase64(id Identicon) (string, error) {
    img, err := render(id)
    if err != nil {
        return "", err
    }
    encodedString := base64.StdEncoding.EncodeToString(img)
    image := "data:image/png;base64," + encodedString
    return image, nil
}

func setBackgroundTransparent(img *image.RGBA) {
    draw.Draw(img, img.Bounds(), &image.Uniform{C: color.Transparent}, image.Point{}, draw.Src)
}

func drawRect(rgba *image.RGBA, i int, c color.Color) {
    sizeSquare := 6
    maxRow := 5

    r := image.Rect(
        10+(i%maxRow)*sizeSquare,
        10+(i/maxRow)*sizeSquare,
        10+(i%maxRow)*sizeSquare+sizeSquare,
        10+(i/maxRow)*sizeSquare+sizeSquare,
    )

    draw.Draw(rgba, r, &image.Uniform{C: c}, image.Point{}, draw.Src)
}

func render(id Identicon) ([]byte, error) {
    img := image.NewRGBA(image.Rect(0, 0, Width, Height))
    var buff bytes.Buffer

    setBackgroundTransparent(img)

    for i, v := range id.bitmap {
        if v == 1 {
            drawRect(img, i, id.color)
        }
    }

    if err := png.Encode(&buff, img); err != nil {
        return nil, err
    }

    return buff.Bytes(), nil
}

// GenerateBase64 generates an identicon in base64 png format given a string
func GenerateBase64(id string) (string, error) {
    i := generate(id)
    return renderBase64(i)
}

func Generate(id string) ([]byte, error) {
    i := generate(id)
    return render(i)
}