identicon

package module
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 Go to latest Published: Jun 26, 2019 License: MIT Imports: 12 Imported by: 0

README

IdentIcon

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IdentIcon is an open source avatar generator inspired by GitHub avatars.

IdentIcon uses a deterministic algorithm that generates an image (using Golang's stdlib image encoders) based on a text (Generally Usernames, Emails or just random strings), by hashing it and iterating over the bytes of the digest to pick whether to draw a point, pick a color or choose where to go next.

IdentIcon's Generator enables the creation of customized figures: (NxN size, points density, custom color palette) as well as multiple exporting formats in case the developers want to generate their own images.

Installation

$ go get github.com/nullrocks/identicon

Usage


import (
    "os"

    "github.com/nullrocks/identicon"
)

// New Generator: Rehuse 
ig, err := identicon.New(
    "github", // Namespace
    5,        // Number of blocks (Size)
    3,        // Density
)

if err != nil {
    panic(err) // Invalid Size or Density
}

username := "nullrocks"      // Text - decides the resulting figure
ii, err := ig.Draw(username) // Generate an IdentIcon

if err != nil {
    panic(err) // Text is empty
}

// File writer
img, _ := os.Create("icon.png")
defer img.Close()
// Takes the size in pixels and any io.Writer
ii.Png(300, img) // 300px * 300px

Examples

5x5
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
7x7
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
10x10
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo
nullrocks johndoe abc123 modulo

View examples

Documentation

Changelog

Contribution

License

MIT

Copyright (c) 2018-present, Ruben Rivera

Documentation

Overview

Package identicon is an open source avatar generator inspired by GitHub avatars.

IdentIcon uses a deterministic algorithm that generates an image (using Golang's stdlib image encoders) based on a text (Generally Usernames, Emails or just random strings), by hashing it and iterating over the bytes of the digest to pick whether to draw a point, pick a color or choose where to go next.

IdentIcon's Generator enables the creation of customized figures: (NxN size, points density, custom color palette) as well as multiple exporting formats in case the developers want to generate their own images.

Example 
ig, err := New(
	"github.com", // namespace
	5,            // number of blocks (size)
	2,            // density of points
)

if err != nil {
	panic(err)
}

username := "nullrocks"
ii, err := ig.Draw(username) // Generate an IdentIcon

if err != nil {
	panic(err)
}

// File writer
// img, _ := os.Create("./examples/" + username + ".png")
// defer img.Close()
// Takes the size in pixels and an io.Writer
// ii.Png(300, img) // 300px * 300px

fmt.Println(ii.String(" ", "."))

Output:

. . . . .
1 1 1 1 1
1 . 1 . 1
. . 2 . .
. . . . .

Index

Examples

Constants

View Source 
const (
	// MinSize is the minimal number of blocks allowed, anything lower that this
	// wouldn't make sense.
	MinSize = 4
)

Constrains for the size of the IdentIcon.

Variables

This section is empty.

Functions

func SetBackgroundColorFunction 

func SetBackgroundColorFunction(bcf func([]byte, color.Color) color.Color) option

SetBackgroundColorFunction replaces the default background's color generation function (HSL).

func SetFillColorFunction 

func SetFillColorFunction(fcf func([]byte) color.Color) option

SetFillColorFunction replaces the default color generation function (HSL).

func SetHashFunction 

func SetHashFunction(hf func([]byte) []byte) option

SetHashFunction replaces the default hash function (Sha256).

func SetRandom 

func SetRandom(r bool) option

SetRandom to append a random string to the generator text everytime Draw is called.

Types

type Canvas 

type Canvas struct {
	// Size same value specified in identicon.New(...).
	Size int
	// PointsMap contains all coordinates and it's values that form the figure.
	PointsMap map[int]map[int]int
	// MinY is the upper Y-axis that has at least one point drawn.
	MinY int
	// MaxY is the lower Y-axis that has at least one point drawn.
	MaxY int
	// VisitedYPoints contains all Y-axis that had been visited. Helpful to
	// determine big blank spaces in the resulting figure.
	VisitedYPoints map[int]bool
	// FilledPoints is the number of points filled at least once.
	FilledPoints int
}

Canvas contains what is needed to generate an image. It contains properties that could be useful when rendering the image.

  • Having MinY and MaxY allows you to vertically center the figure.
  • VisitedYPoints could be useful to determine whether there is a big empty vertical space in the figure.

func (*Canvas) Array 

func (c *Canvas) Array() [][]int

Array generates a two-dimensional array version of the IdentIcon figure.

func (*Canvas) IntCoordinates 

func (c *Canvas) IntCoordinates() [][]int

IntCoordinates generates an array of points of a two-dimensional plane as:

  • [x, y] that correspond to all filled points in the IdentIcon figure.

func (*Canvas) Points 

func (c *Canvas) Points() []image.Point

Points generates an array of points of a two-dimensional plane as [x, y] that correspond to all filled points in the IdentIcon figure.

func (*Canvas) String 

func (c *Canvas) String(separator string, fillEmptyWith string) string

ToString generates a string version of the IdentIcon figure.

type Generator 

type Generator struct {
	// Namespace that will be concatenated previous to the icon generation.
	Namespace string
	// Size is the number of blocks of the figure.
	Size int
	// Density * Size = times to iterate over the hash of Text:Namespace:Seed.
	Density int
	// contains filtered or unexported fields
}

Generator represents a predefined set of configurations that can be reused to create multiple icons by passing a Text string only.

func New 

func New(
	namespace string,
	size int,
	density int,
	opts ...option,
) (*Generator, error)

New returns a pointer to a Generator with the desired configuration.

Example (CustomOptions) 
alwaysRed := func(cb []byte) color.Color {
	return color.RGBA{255, 0, 0, 255}
}

transparentBg := func(cb []byte, fc color.Color) color.Color {
	return color.Transparent
}

ig, _ := New(
	"",
	7,
	4,
	SetRandom(true),                 // Resultant image will be random
	SetFillColorFunction(alwaysRed), // Points will be red
	SetBackgroundColorFunction(transparentBg), // Background will be transparent
)

// All generated IdentIcons will match configuration (fill=red, bg=transparent, isRandom=true)
ig.Draw("nullrocks")
ig.Draw("username")
ig.Draw("admin")

Output:

func (Generator) Draw 

func (g Generator) Draw(text string) (*IdentIcon, error)

Draw returns a pointer to an IdentIcon with a generated figure and a color.

Example (Size7x7withNamespace) 
ig, err := New(
	"null.rocks",
	7,
	4,
)

if err != nil {
	panic(err)
}

username := "admin"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

fmt.Println(ii.GeneratorText())
fmt.Println(ii.String(" ", "."))

Output:

admin:null.rocks
. 1 2 . 2 1 .
. 2 . . . 2 .
. . . 1 . . .
. . . 1 . . .
2 . . 4 . . 2
. . 4 2 4 . .
. 1 2 1 2 1 .

func (*Generator) Option 

func (g *Generator) Option(opts ...option)

Option sets the options specified.

type HSL 

type HSL struct {
	// Hue [0, 360]
	H uint32
	// Saturation [0, 100]
	S uint32
	// Lightness [0, 100]
	L uint32
}

HSL is a color model representation based on RGB. HSL facilitates the generation of colors that look similar between themselves by changing the value of Hue H while keeping Saturation S and Lightness L the same.

func (HSL) RGBA 

func (hsl HSL) RGBA() (r, g, b, a uint32)

RGBA conversion

type IdentIcon 

type IdentIcon struct {
	// Text is the base string that will generate the canvas after being hashed.
	Text string
	// Namespace
	Namespace string

	// Size is the number of blocks of the figure.
	Size int
	// Density * Size = times to iterate over the hash of Text.
	Density int
	// Canvas is a map of maps that contains the points and values that has been
	// visited and filled.
	Canvas Canvas

	// FillColor is the color used to fill squares in the figure when encoding
	// to PNG or JPEG.
	FillColor color.Color
	// BackgroundColor is the background color of the figure when encoding it to
	// PNG or JPEG.
	BackgroundColor color.Color
	// contains filtered or unexported fields
}

IdentIcon represents a mirror-symmetry image generated from a string and a set of configurations.

func (*IdentIcon) Array 

func (ii *IdentIcon) Array() [][]int

Array generates a two-dimensional array version of the IdentIcon figure.

Example 
ig, err := New("github.com", 7, 4)

if err != nil {
	panic(err)
}

username := "nullrocks"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

// Array representation of the IdentIcon
arr := ii.Array()
fmt.Print(arr)

Output:

[[3 1 0 2 0 1 3] [5 1 0 1 0 1 5] [2 2 0 0 0 2 2] [0 0 0 0 0 0 0] [0 0 0 0 0 0 0] [0 0 0 0 0 0 0] [1 0 2 1 2 0 1]]

func (*IdentIcon) Draw 

func (ii *IdentIcon) Draw()

Draw a figure in Canvas.

  • If isRandom == true, the figure will redrawn everytime Draw() is called,
  • If isRandom == false and Draw() was called before, it won't redraw.

func (*IdentIcon) GeneratorText 

func (ii *IdentIcon) GeneratorText() string

GeneratorText returns the string later to be hashed using the format:

  • Text[:Namespace][:randomSeed]
Example 
ig, err := New("namespace", 7, 4)

if err != nil {
	panic(err)
}

username := "text"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

fmt.Print(ii.GeneratorText())

Output:

text:namespace

func (*IdentIcon) Image 

func (ii *IdentIcon) Image(pixels int) image.Image

Image genetares an image.Image of size

func (*IdentIcon) IntCoordinates 

func (ii *IdentIcon) IntCoordinates() [][]int

IntCoordinates generates an array of points of a two-dimensional plane as:

  • [x, y] that correspond to all filled points in the IdentIcon figure.

func (*IdentIcon) Jpeg 

func (ii *IdentIcon) Jpeg(pixels int, quality int, w io.Writer) error

Jpeg writes an image of pixels and quality

Example 
ig, err := New("", 7, 4)

if err != nil {
	panic(err)
}

username := "yourUsername"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

// File writer
img, _ := os.Create("./examples/" + username + ".jpg")
defer img.Close()

quality := 90

// Takes the size in pixels, quality and an io.Writer
ii.Jpeg(300, quality, img) // 300px * 300px

Output:

func (*IdentIcon) Png 

func (ii *IdentIcon) Png(pixels int, w io.Writer) error

Png writes an image of pixels

Example 
ig, err := New("", 7, 4)

if err != nil {
	panic(err)
}

username := "yourUsername"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

// File writer
img, _ := os.Create("./examples/" + username + ".png")
defer img.Close()
// Takes the size in pixels and an io.Writer
ii.Png(300, img) // 300px * 300px

Output:
Example (Base64Encoded) 
ig, err := New("", 7, 4)

if err != nil {
	panic(err)
}

username := "yourUsername"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

// File writer
out := new(bytes.Buffer)
// Takes the size in pixels and an io.Writer
ii.Png(300, out) // 300px * 300px

str := base64.StdEncoding.EncodeToString(out.Bytes())
fmt.Println(str)

Output:

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

func (*IdentIcon) Points 

func (ii *IdentIcon) Points() []image.Point

Points generates an array of points of a two-dimensional plane as [x, y] that correspond to all filled points in the IdentIcon figure.

Example 
ig, err := New("github.com", 7, 4)

if err != nil {
	panic(err)
}

username := "userName123"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

// Array of image.Points representation of the IdentIcon
ps := ii.Points()
fmt.Print(ps)

Output:

func (*IdentIcon) String 

func (ii *IdentIcon) String(separator string, fillEmptyWith string) string

ToString generates a string version of the IdentIcon figure.

Example 
ig, err := New("github.com", 7, 4)

if err != nil {
	panic(err)
}

username := "userName12345"
ii, err := ig.Draw(username)

if err != nil {
	panic(err)
}

// String representation of the IdentIcon
// separator = " "
// fill empty blocks = "."
str := ii.String(" ", ".")
fmt.Print(str)

Output:

. 2 4 . 4 2 .
1 1 . . . 1 1
. . 2 2 2 . .
1 . . 1 . . 1
. . . . . . .
. . . . . . .
. 2 1 1 1 2 .

func (*IdentIcon) Svg 

func (ii *IdentIcon) Svg(pixels int, w io.Writer) error

Svg writes an image of pixels

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