
Allegro (software library)

Allegro is a software library for video game development. The functionality of the library includes support for basic 2D graphics, image manipulation, text output, audio output, MIDI music, input and timers, as well as additional routines for fixed-point and floating-point matrix arithmetic, Unicode strings, file system access, file manipulation, data files, and 3D graphics. The library is written in the C programming language and designed to be used with C, C++, or Objective-C, with bindings available for Python, Lua, Scheme, D, Go, and other languages. Allegro comes with extensive documentation and many examples.
Allegro supports Windows, macOS, Unix-like systems, Android, and iOS, abstracting their application programming interfaces (APIs) into one portable interface. Previous versions up to 4.4 supported Windows, macOS, DOS, BeOS, and various Unix-like systems with (or without) the X Window System. There is also an independent port of Allegro on AmigaOS 4 and MorphOS.
Released under the terms of the zlib license, Allegro is free and open source software.
History.
Initially standing for "Atari Low-Level Game Routines", Allegro was originally created by for the Atari ST in the early 1990s. However, Hargreaves abandoned the Atari version as he realized the platform was dying, and reimplemented his work for the Borland C++ and DJGPP compilers in 1995. Support for Borland C++ was dropped in version 2.0, and DJGPP was the only supported compiler. As DJGPP was a DOS compiler, all games which used Allegro therefore used DOS. Around 1998, Allegro branched out into several versions. A port to Windows, WinAllegro, was created, and also during this time, a Unix port of Allegro, XwinAllegro, was created. These various ports were brought together during the Allegro 3.9 WIP versions, with Allegro 4.0 being the first stable version of Allegro to support multiple platforms.
Allegro 5.
Current development is focused on the Allegro 5 branch, a complete redesign of both the API and much of the library's internal operation. Effort was made to make the API more consistent and multi-thread safe. By default, the library is now hardware accelerated using OpenGL or DirectX rendering backends where appropriate. Many of the addons that existed as separate projects for Allegro 4 now interface seamlessly with Allegro proper and are bundled with the default installation. Allegro 5 is event driven.
Features.
Allegro provides the following graphic functions:
Addons.
The community of Allegro users have contributed several library extensions to handle things like scrolling tile maps and import and export of various file formats (e.g. PNG, GIF, JPEG images, MPEG video, Ogg, MP3, IT, S3M, XM music, TTF fonts, and more).
Allegro 4.x and below can be used in conjunction with OpenGL by using the library "AllegroGL" which extends Allegro's functionality into OpenGL and therefore the hardware. Allegro 5 natively supports OpenGL.