rqr

A small QR code generation project I made to dip my toes into rust again after several years of absence. I was always curious on how QR codes worked and it was a pretty good project to explore rust with. I followed an excellent tutorial to learn of to implement a QR code generator.

I don't plan on maintaining the project or add features to it. Feel free to look at the code to learn or fork it and do something with it.

As with all QR code libs always verify the output before using it for real.

Documentation

Cargo.toml

toml [dependencies] rqr = "0.1.0"

Examples

String generation

A simple string representation can be created like so:

```rust extern crate rqr; use rqr::{Qr, StringRenderer};

fn main() { let qr = Qr::new("HELLO WORLD").unwrap(); let s = StringRenderer::new().render(&qr); println!("{}", s); } ```

Producing the output:

```

#....#..

.....#.##..#.#.....

.###.#..#.##.#.###.

.###.#.#####.#.###.

.###.#.##.#..#.###.

.....#..#..#.#.....

#.#.#.#.

........##.##........ .#.####.##..###.##.#.

.####.#....####.###.

..#.#.##...#..##.....

.##.#...#.##...##...

.########.###.

........#...#..#.#...

#..##..##..

.....#.#.#..#..#.

.###.#.##.#..#...

.###.#.#.###...#.#..

.###.#..#....#....

.....#.###..###..##.

#..#.#.......#.

```

Rendering can be customized:

rust let s = StringRenderer::new() .light_module(' ') .dark_module('X') .module_dimensions(2, 1) .render(&qr);

To produce:

XXXXXXXXXXXXXX XX XXXXXXXXXXXXXX XX XX XXXX XX XX XX XX XXXXXX XX XX XXXX XX XXXXXX XX XX XXXXXX XX XXXXXXXXXX XX XXXXXX XX XX XXXXXX XX XXXX XX XX XXXXXX XX XX XX XX XX XX XX XXXXXXXXXXXXXX XX XX XX XXXXXXXXXXXXXX XXXX XXXX XX XXXXXXXX XXXX XXXXXX XXXX XX XX XXXXXXXX XX XXXXXXXX XXXXXX XX XX XXXX XX XXXX XX XXXX XX XX XXXX XXXX XXXX XXXXXXXXXXXXXXXX XXXXXX XXXXXXXXXX XX XX XX XX XXXXXXXXXXXXXX XXXX XXXX XXXXXXXX XX XX XX XX XX XX XXXXXX XX XXXXXX XX XXXX XX XX XXXXXX XX XXXXXX XX XX XXXXXX XX XX XX XXXXXX XX XX XX XXXX XX XX XXXXXX XXXXXX XXXX XXXXXXXXXXXXXX XX XX XX

SVG generation

An svg file can be produced with:

```rust use rqr::{Qr, SvgRenderer, Color, ECLevel};

fn main() { let qr = Qr::withecl("HELLO WORLD", ECLevel::Q).unwrap(); let s = SvgRenderer::new() .lightmodule(Color::new(229, 189, 227)) .dark_module(Color::new(119, 0, 0)) .dimensions(200, 200) .render(&qr); println!("{}", s); } ```

Customize QR values

You can override inferred QR code defalts by interfacing against the builder. Normally you should only specify the error correction level, the other values are inferred optimally.

rust let qr = QrBuilder::new() .ecl(ECLevel::L) .version(Version::new(3)) .mask(Mask::new(0)) .mode(Mode::Alphanumeric) .into("1234567890") .unwrap();

It's possible to gain even more fine grained control, like adding raw bits, both via the builder or against the matrix directly.

CLI

There's a simple cli you can use.

It uses optional dependencies to avoid arg parser dependencies to the library, so you need to build it with the flag --features cli.

For example to pretty print a QR in a terminal:

```

cargo run --features cli -- "HELLO WORLD"

    ██████████████        ██    ██████████████        
    ██          ██  ████    ██  ██          ██        
    ██  ██████  ██    ██  ████  ██  ██████  ██        
    ██  ██████  ██  ██████████  ██  ██████  ██        
    ██  ██████  ██  ████  ██    ██  ██████  ██        
    ██          ██    ██    ██  ██          ██        
    ██████████████  ██  ██  ██  ██████████████        
                    ████  ████                        
      ██  ████████  ████    ██████  ████  ██          
    ██  ████████  ██        ████████  ██████          
        ██  ██  ████      ██    ████                  
    ██  ████  ██      ██  ████      ████              
    ████  ████████████████  ██████  ██████████        
                    ██      ██    ██  ██              
    ██████████████    ████    ████    ████████        
    ██          ██  ██  ██    ██    ██  ██████        
    ██  ██████  ██  ████  ██    ██      ██████        
    ██  ██████  ██  ██  ██████      ██  ██            
    ██  ██████  ██    ██        ██        ████        
    ██          ██  ██████    ██████    ████          
    ██████████████    ██  ██              ██

```

Or to generate an svg:

```

cargo run --features cli -- "HELLO WORLD" -t svg --bg '#e5bde3' \ --fg '#700' --width 200 > hello_world.svg ```

This outputs the same as the above example svg code.