github.com/status-im/status-go@v1.1.0/protocol/identity/identicon/renderer.go (about)

     1  package identicon
     2  
     3  import (
     4  	"bytes"
     5  	"encoding/base64"
     6  	"image"
     7  	"image/color"
     8  	"image/draw"
     9  	"image/png"
    10  )
    11  
    12  const (
    13  	Width  = 50
    14  	Height = 50
    15  )
    16  
    17  func renderBase64(id Identicon) (string, error) {
    18  	img, err := render(id)
    19  	if err != nil {
    20  		return "", err
    21  	}
    22  	encodedString := base64.StdEncoding.EncodeToString(img)
    23  	image := "data:image/png;base64," + encodedString
    24  	return image, nil
    25  }
    26  
    27  func setBackgroundTransparent(img *image.RGBA) {
    28  	draw.Draw(img, img.Bounds(), &image.Uniform{C: color.Transparent}, image.Point{}, draw.Src)
    29  }
    30  
    31  func drawRect(rgba *image.RGBA, i int, c color.Color) {
    32  	sizeSquare := 6
    33  	maxRow := 5
    34  
    35  	r := image.Rect(
    36  		10+(i%maxRow)*sizeSquare,
    37  		10+(i/maxRow)*sizeSquare,
    38  		10+(i%maxRow)*sizeSquare+sizeSquare,
    39  		10+(i/maxRow)*sizeSquare+sizeSquare,
    40  	)
    41  
    42  	draw.Draw(rgba, r, &image.Uniform{C: c}, image.Point{}, draw.Src)
    43  }
    44  
    45  func render(id Identicon) ([]byte, error) {
    46  	img := image.NewRGBA(image.Rect(0, 0, Width, Height))
    47  	var buff bytes.Buffer
    48  
    49  	setBackgroundTransparent(img)
    50  
    51  	for i, v := range id.bitmap {
    52  		if v == 1 {
    53  			drawRect(img, i, id.color)
    54  		}
    55  	}
    56  
    57  	if err := png.Encode(&buff, img); err != nil {
    58  		return nil, err
    59  	}
    60  
    61  	return buff.Bytes(), nil
    62  }
    63  
    64  // GenerateBase64 generates an identicon in base64 png format given a string
    65  func GenerateBase64(id string) (string, error) {
    66  	i := generate(id)
    67  	return renderBase64(i)
    68  }
    69  
    70  func Generate(id string) ([]byte, error) {
    71  	i := generate(id)
    72  	return render(i)
    73  }