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(3alleg4),
allegro_exit(3alleg4),
set_uformat(3alleg4),
set_config_file(3alleg4)