If you feel that Fukuchi's library is too large[0] for you, consider looking at Nayuki's C++ QR Code generator library[1]: https://github.com/nayuki/QR-Code-generator/tree/master/cpp
Nayuki's library requires C++11, and is portable without needing Autotools. Sample usage:
#include <string>#include <vector>#include "QrCode.hpp"using namespace qrcodegen;// Create the QR Code objectQrCode qr = QrCode::encodeText("Hello, world!", QrCode::Ecc::MEDIUM);// Read the black & white pixelsfor (int y = 0; y < qr.size; y++) { for (int x = 0; x < qr.size; x++) { int color = qr.getModule(x, y); // 0 for white, 1 for black // You need to modify this part draw_pixel_onto_QT(x, y, color); }}[0]: Fukuchi: 20 files, ~7200 lines among the main .c and .h files (excluding build and test code).
[1]: Nayuki: 6 files, ~1400 lines among the main .cpp and .hpp files (excluding demo code).
EDIT 2016-12-08 by OPI decided, with permission, to add my own adaption to Qt. This code compiles and runs fine on my system, And I think it should be independent enough to work elsewhere without too many tweaks as well.
#include "QrCode.hpp"void paintQR(QPainter &painter, const QSize sz, const QString &data, QColor fg){ // NOTE: At this point you will use the API to get the encoding and format you want, instead of my hardcoded stuff: qrcodegen::QrCode qr = qrcodegen::QrCode::encodeText(data.toUtf8().constData(), qrcodegen::QrCode::Ecc::LOW); const int s=qr.getSize()>0?qr.getSize():1; const double w=sz.width(); const double h=sz.height(); const double aspect=w/h; const double size=((aspect>1.0)?h:w); const double scale=size/(s+2); // NOTE: For performance reasons my implementation only draws the foreground parts in supplied color. // It expects background to be prepared already (in white or whatever is preferred). painter.setPen(Qt::NoPen); painter.setBrush(fg); for(int y=0; y<s; y++) { for(int x=0; x<s; x++) { const int color=qr.getModule(x, y); // 0 for white, 1 for black if(0!=color) { const double rx1=(x+1)*scale, ry1=(y+1)*scale; QRectF r(rx1, ry1, scale, scale); painter.drawRects(&r,1); } } }}For usage, please see this painter class.
