install_allegro(3)              Allegro manual              install_allegro(3)



NAME
       install_allegro - Initialise the Allegro library.

SYNOPSIS
       #include <allegro.h>


       int install_allegro(int system_id, int *errno_ptr, int
       (*atexit_ptr)());

DESCRIPTION
       Initialises the Allegro library. You must call either this or
       allegro_init() before doing anything other than using the Unicode
       routines. If you want to use a text mode other than UTF-8, you can set
       it with set_uformat() before you call this. The other functions that
       can be called before this one will be marked explicitly in the
       documentation, like set_config_file().

       The available system ID codes will vary from one platform to another,
       but you will almost always want to pass SYSTEM_AUTODETECT.
       Alternatively, SYSTEM_NONE installs a stripped down version of Allegro
       that won't even try to touch your hardware or do anything platform
       specific: this can be useful for situations where you only want to
       manipulate memory bitmaps, such as the text mode datafile tools or the
       Windows GDI interfacing functions.

       The `errno_ptr' and `atexit_ptr' parameters should point to the errno
       variable and atexit function from your libc: these are required because
       when Allegro is linked as a DLL, it doesn't have direct access to your
       local libc data. `atexit_ptr' may be NULL, in which case it is your
       responsibility to call allegro_exit() manually. Example:

          install_allegro(SYSTEM_AUTODETECT, &errno, atexit);

RETURN VALUE
       This function returns zero on success and non-zero on failure (e.g. no
       system driver could be used). Note: in previous versions of Allegro
       this function would abort on error.


SEE ALSO
       allegro_init(3), allegro_exit(3), set_uformat(3), set_config_file(3)



Allegro                          version 4.2.3              install_allegro(3)
