https://github.com/spider-gazelle/qr-code

a QR Code implementation written in crystal lang
https://github.com/spider-gazelle/qr-code

Last synced: 3 months ago
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a QR Code implementation written in crystal lang

• Host: GitHub
• URL: https://github.com/spider-gazelle/qr-code
• Owner: spider-gazelle
• License: mit
• Created: 2020-11-02T22:00:52.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2024-01-04T12:42:30.000Z (10 months ago)
• Last Synced: 2024-06-21T18:09:40.741Z (5 months ago)
• Language: Crystal
• Size: 26.4 KB
• Stars: 17
• Watchers: 6
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-crystal - qr-code - QR Code generator (Algorithms and Data structures)

README

        
# Crystal Lang QR Code

[![CI](https://github.com/spider-gazelle/qr-code/actions/workflows/ci.yml/badge.svg)](https://github.com/spider-gazelle/qr-code/actions/workflows/ci.yml)

Native crystal lang QR code, no external dependencies

## Installation

1. Add the dependency to your `shard.yml`:

   ```yaml

   dependencies:

     qr-code:

       github: spider-gazelle/qr-code

   ```

2. Run `shards install`

## Usage

```crystal

require "qr-code"

qr = QRCode.new("my string to generate", size: 4, level: :h)

puts qr.to_s

```

output

```

xxxxxxx x  x x   x x  xx  xxxxxxx

x     x  xxx  xxxxxx xxx  x     x

x xxx x  xxxxx x       xx x xxx x

... etc

```

### Doing your own rendering

```crystal

require "qr-code"

qr = QRCode.new("my string to generate", size: 4, level: :h)

qr.modules.each do |row|

  row.each do |col|

    print col ? '#' : ' '

  end

  print "\n"

end

```

### Rendering a SVG

```crystal

require "qr-code"

svg_string = QRCode.new("my string to generate").as_svg

```

### Rendering a PNG

you'll need to add [stumpy_png](https://github.com/stumpycr/stumpy_png) to your `shard.yml` dependencies

```crystal

require "qr-code"

require "qr-code/export/png"

# size == width, and QR codes are square

png_bytes = QRCode.new("my string to generate").as_png(size: 256)

```

## Credits

Based off the ruby gem: https://github.com/whomwah/rqrcode_core

Which was adapted from the javascript library: https://github.com/kazuhikoarase/qrcode-generator