Readme.markdown
1QR Code generator library - Rust, no heap
2=========================================
3
4
5Introduction
6------------
7
8This 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.
9
10Home page with live JavaScript demo, extensive descriptions, and competitor comparisons: https://www.nayuki.io/page/qr-code-generator-library
11
12
13Features
14--------
15
16Core features:
17
18* Significantly shorter code but more documentation comments compared to competing libraries
19* Supports encoding all 40 versions (sizes) and all 4 error correction levels, as per the QR Code Model 2 standard
20* Output format: Raw modules/pixels of the QR symbol
21* Detects finder-like penalty patterns more accurately than other implementations
22* Encodes numeric and special-alphanumeric text in less space than general text
23* Completely avoids heap allocation (e.g. `std::vec::Vec`), instead relying on suitably sized buffers from the caller and fixed-size stack allocations
24* Open-source code under the permissive MIT License
25
26Manual parameters:
27
28* User can specify minimum and maximum version numbers allowed, then library will automatically choose smallest version in the range that fits the data
29* User can specify mask pattern manually, otherwise library will automatically evaluate all 8 masks and select the optimal one
30* User can specify absolute error correction level, or allow the library to boost it if it doesn't increase the version number
31* User can create a list of data segments manually and add ECI segments
32
33More information about QR Code technology and this library's design can be found on the project home page.
34
35
36Examples
37--------
38
39```rust
40extern crate qrcodegen;
41use qrcodegen::Mask;
42use qrcodegen::QrCode;
43use qrcodegen::QrCodeEcc;
44use qrcodegen::Version;
45
46// Text data
47let mut outbuffer = vec![0u8; Version::MAX.buffer_len()];
48let mut tempbuffer = vec![0u8; Version::MAX.buffer_len()];
49let qr = QrCode::encode_text("Hello, world!",
50 &mut tempbuffer, &mut outbuffer, QrCodeEcc::Medium,
51 Version::MIN, Version::MAX, None, true).unwrap();
52let svg = to_svg_string(&qr, 4); // See qrcodegen-demo
53
54// Binary data
55let mut outbuffer = vec![0u8; Version::MAX.buffer_len()];
56let mut dataandtemp = vec![0u8; Version::MAX.buffer_len()];
57dataandtemp[0] = 0xE3;
58dataandtemp[1] = 0x81;
59dataandtemp[2] = 0x82;
60let qr = QrCode::encode_binary(&mut dataandtemp, 3,
61 &mut outbuffer, QrCodeEcc::High,
62 Version::new(2), Version::new(7),
63 Some(Mask::new(4)), false).unwrap();
64for y in 0 .. qr.size() {
65 for x in 0 .. qr.size() {
66 (... paint qr.get_module(x, y) ...)
67 }
68}
69```
70
71More complete set of examples: https://github.com/nayuki/QR-Code-generator/blob/master/rust-no-heap/examples/qrcodegen-demo.rs .
72