glbarcode++

Introduction

glbarcode++ is a free C++ library for generating barcodes. It is a port of the original glbarcode library from gLabels. The library is designed to be easily extended to support new barcode types and output formats.

glbarcode++ is a C++ port of the glabels barcode library and is currently early in development. Expect the API to be somewhat unstable in the 0.x series.

Supported Symbologies

glbarcode++ currently supports the following barcode symbologies.

Name	Example	Data Length	Data Format	Text Visible	Checksum Generated	Notes
Code39		Variable	`A`-`Z`, `0`-`9` space special:`-.$/+%`	Optional	Optional	1
Extended Code39		Variable	Full ASCII range (0-127)	Optional	Optional
UPC-A		11	`0`-`9`	Always	Always
EAN-13		12	`0`-`9`	Always	Always
ONECODE		20, 25, 29 or 31	`0`-`9`	Never	Always
POSTNET		5, 9 or 11	`0`-`9`	Never	Always	2
POSTNET-5		5	`0`-`9`	Never	Always	2
POSTNET-9		9	`0`-`9`	Never	Always	2
POSTNET-11		11	`0`-`9`	Never	Always	2
CEPNET		8	`0`-`9`	Never	Always	2
Data Matrix		Variable	Full 8-bit values	Never	Always	3, 4, 5
QR Code		Variable	Full 8-bit values, except 0	Never	Always	6

Notes

1. Lowercase letters (a-z) are upshifted
2. Spaces and dashes ('-') in input are ignored
3. Supports up to 1558 code words. The exact encoding limit depends on the data. For example, if the data is composed entirely of ASCII digits (0-9), up to 3116 digits can be encoded.
4. Only supports the ECC 200 version.
5. Currently only uses the ASCII encoding method which may not be optimal for all data.
6. QR Code encoding is currently not native to glbarcode++. It is implemented as a thin wrapper around qrencode library (http://fukuchi.org/works/qrencode/index.html).

Overview

This manual is divided into two parts, each of which is divided into separate sections.

The first part is the general user manual:

• Usage – This section describes the basic usage of the library.
• Extending – This section describes how to extend the functionality of the library.
  • Drawing Primitives – This section describes the internal representation of atomic drawing elements of a barcode.
  • Implementing 1D Barcodes – This section describes how to implement new 1D barcode types (or symbologies).
  • Implementing 2D Barcodes – This section describes how to implement new 2D barcode types (or symbologies).
  • Implementing Renderers – This section describes how to implement new renderers for different output formats.
• GNU Lesser General Public License – The glbarcode++ license (see below).

The second part is the detailed API reference:

• Class List
• File List

glbarcode++ License

Copyright © 2013-2026 Jaye Evins <evins@snaught.com>

glbarcode++ is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

glbarcode++ is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with glbarcode++. If not, see http://www.gnu.org/licenses/.