allegro是一個c/c++的遊戲庫，免費，開源，最初作者是shawn hargreaves，他支持DOS，UNIX（Linux, FreeBSD, Irix, Solaris, Darwin), Windows, QNX, BeOS 還有 MacOS X.提供了大量的圖形，聲音，玩家輸入(鍵盤，滑鼠，遊戲手柄)，定時器等函式。它支持定點和浮點
數學函式，3D函式，檔案管理函式，數據檔案壓縮，和GUI等功能。
Cross-platform support
Unix (Linux, FreeBSD, Irix, Solaris, Darwin)
Windows (MSVC, MinGW, Cygwin, Borland)
BeOS
QNX
MacOS X
Dos (DJGPP, Watcom)
Graphic functions
Vector drawing:
pixels, lines, rectangles, circles, ellipses, arcs, Bezier splines
shape fill, with or without pattern
polygons: flat, Gouraud, textured (3D) and translucent
Sprites:
masked, compressed and compiled sprites
blitting, rotation, stretching, reduction, alpha blending, Gouraud shading
native support for BMP, LBM, PCX and TGA files (others supported with library extensions)
Color palettes:
color palette manipulation (reading, writing, conversion)
conversion of color formats RGB <-> HSV
Text:
support for different encodings and conversion, default is UTF-8
bitmap fonts (masking, colouring, alignment)
Misc:
draw directly on the screen or on any-size memory bitmaps
hardware scrolling and triple buffering (where available), mode-X split screen
animation functions for FLI/FLC format
Graphic drivers
Unix:
X Window, DGA, fbcon
SVGAlib
VBE/AF
mode-X
VGA
Windows:
DirectX (windowed or full-screen)
GDI
MacOS X:
Quartz (windowed or full-screen)
BeOS:
BWindowScreen
BDirectWindow
Dos:
VGA 13h mode
mode-X (23 VGA resolution plus unchained 640x400 extended mode)
SVGA modes in 8, 15, 16, 24 and 32 bits per pixel
linear VBE 2.0 framebuffer access
hardware acceleration through VBE/AF API if supported
additional graphic drivers through FreeBE/AF project
OpenGL:
The AllegroGL addon allows to use OpenGL graphics with Allegro.
Sound functions
Midi:
native MIDI music format support (with 64 simultaneous effects)
dynamic control/response to music note on, note off, main volume, pan, pitch bend, and program change
uses General MIDI patches
you can read in wavetable patches for MIDI files (SF2 and GUS patches)
Wave:
native support of WAV and VOC file formats (playing looped forward, backwards or bidirectional)
streaming audio
modify volume, pan, pitch, etc during play
Sound drivers
Unix:
OSS
ALSA (0.5/0.9/1.0)
ESD
aRts
JACK
SGI AL
Windows:
DirectSound
WaveOut
MIDI system drivers
MacOS X:
Core Audio
Sound Manager
Core Audio MIDI
QuickTime MIDI
Dos:
Adlib, SB, SB Pro, SB16, AWE32
MPU-401
ESS AudioDrive
Ensoniq Soundscape
Windows Sound System
Math functions
fixed point arithmetic and trigonometric routines
precalculated trigonometric tables
vector/matrix/quaternions 3d manipulation (translation, rotation, scaling, projection)
Misc
mouse, keyboard and joystick management
high resolution interrupt timers (resolution of 10, 5 or less ms depending on platform)
vertical retrace simulation
manipulate configuration files
manipulate compressed files in LZSS format
manipulate multi-object resource-like compressed datafiles
tool for creating datafiles (grabber)
simple GUI for dialogs and file selector
