Crate qrcodegen_no_heap

source ·
Expand description

Generates QR Codes from text strings and byte arrays.

This project aims to be the best, clearest QR Code generator library. The primary goals are flexible options and absolute correctness. Secondary goals are compact implementation size and good documentation comments.

Home page with live JavaScript demo, extensive descriptions, and competitor comparisons: https://www.nayuki.io/page/qr-code-generator-library

Features

Core features:

  • Significantly shorter code but more documentation comments compared to competing libraries
  • Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
  • Output format: Raw modules/pixels of the QR symbol
  • Detects finder-like penalty patterns more accurately than other implementations
  • Encodes numeric and special-alphanumeric text in less space than general text
  • Open-source code under the permissive MIT License

Manual parameters:

  • User can specify minimum and maximum version numbers allowed, then library will automatically choose smallest version in the range that fits the data
  • User can specify mask pattern manually, otherwise library will automatically evaluate all 8 masks and select the optimal one
  • User can specify absolute error correction level, or allow the library to boost it if it doesn’t increase the version number
  • User can create a list of data segments manually and add ECI segments

More information about QR Code technology and this library’s design can be found on the project home page.

Examples

extern crate qrcodegen;
use qrcodegen::Mask;
use qrcodegen::QrCode;
use qrcodegen::QrCodeEcc;
use qrcodegen::Version;

Text data:

let mut outbuffer  = vec![0u8; Version::MAX.buffer_len()];
let mut tempbuffer = vec![0u8; Version::MAX.buffer_len()];
let qr = QrCode::encode_text("Hello, world!", &mut tempbuffer, &mut outbuffer,
    QrCodeEcc::Medium, Version::MIN, Version:MAX, None, true).unwrap();
let svg = to_svg_string(&qr, 4);  // See qrcodegen-demo

Binary data:

let mut outbuffer   = vec![0u8; Version::MAX.buffer_len()];
let mut dataandtemp = vec![0u8; Version::MAX.buffer_len()];
dataandtemp[0] = 0xE3;
dataandtemp[1] = 0x81;
dataandtemp[2] = 0x82;
let qr = QrCode::encode_binary(&mut dataandtemp, 3, &mut outbuffer, QrCodeEcc::High,
    Version::new(2), Version::new(7), Some(Mask::new(4)), false).unwrap();
for y in 0 .. qr.size() {
    for x in 0 .. qr.size() {
        (... paint qr.get_module(x, y) ...)
    }
}

Structs

  • BitBuffer
    An appendable sequence of bits (0s and 1s).
  • Mask
    A number between 0 and 7 (inclusive).
  • QrCode
    A QR Code symbol, which is a type of two-dimension barcode.
  • QrSegment
    A segment of character/binary/control data in a QR Code symbol.
  • Version
    A number between 1 and 40 (inclusive).

Enums

  • DataTooLong
    The error type when the supplied data does not fit any QR Code version.
  • QrCodeEcc
    The error correction level in a QR Code symbol.
  • QrSegmentMode
    Describes how a segment’s data bits are interpreted.