System

These functions are declared in the main Allegro header file:

#include <allegro5/allegro.h>

al_install_system

bool al_install_system(int version, int (*atexit_ptr)(void (*)(void)))

Initialize the Allegro system. No other Allegro functions can be called before this (with one or two exceptions).

The version field should always be set to ALLEGRO_VERSION_INT.

If atexit_ptr is non-NULL, and if hasn't been done already, al_uninstall_system will be registered as an atexit function.

Returns true if Allegro was successfully initialized by this function call (or already was initialized previously), false if Allegro cannot be used.

See also: al_init

al_init

#define al_init()    (al_install_system(ALLEGRO_VERSION_INT, atexit))

Like al_install_system, but automatically passes in the version and uses the atexit function visible in the current compilation unit.

See also: al_install_system

al_uninstall_system

void al_uninstall_system(void)

Closes down the Allegro system.

Note: al_uninstall_system() can be called without a corresponding al_install_system call, e.g. from atexit().

al_get_allegro_version

uint32_t al_get_allegro_version(void)

Returns the (compiled) version of the Allegro library, packed into a single integer as groups of 8 bits in the form (major << 24) | (minor << 16) | (revision << 8) | release.

You can use code like this to extract them:

uint32_t version = al_get_allegro_version();
int major = version >> 24;
int minor = (version >> 16) & 255;
int revision = (version >> 8) & 255;
int release = version & 255;

The release number is 0 for an unofficial version and 1 or greater for an official release. For example "5.0.2[1]" would be the (first) official 5.0.2 release while "5.0.2[0]" would be a compile of a version from the "5.0.2" branch before the official release.

al_get_standard_path

ALLEGRO_PATH *al_get_standard_path(int id)

Gets a system path, depending on the id parameter:

iddescription
ALLEGRO_PROGRAM_PATHDirectory with the executed program.
ALLEGRO_TEMP_PATHPath to the directory for temporary files.
ALLEGRO_SYSTEM_DATA_PATHData path for system-wide installation.
ALLEGRO_USER_DATA_PATHData path for per-user installation.
ALLEGRO_USER_HOME_PATHPath to the user's home directory.
ALLEGRO_USER_SETTINGS_PATHPath to per-user settings directory.
ALLEGRO_SYSTEM_SETTINGS_PATHPath to system-wide settings directory.
ALLEGRO_EXENAME_PATHThe full path to the executable.

Returns NULL on failure. The returned path should be freed with al_destroy_path.

See also: al_set_app_name, al_set_org_name, al_destroy_path

al_set_app_name

void al_set_app_name(const char *app_name)

Sets the global application name.

The application name is used by al_get_standard_path to build the full path to an application's files.

This function may be called before al_init or al_install_system.

See also: al_get_app_name, al_set_org_name

al_set_org_name

void al_set_org_name(const char *org_name)

Sets the global organization name.

The organization name is used by al_get_standard_path to build the full path to an application's files.

This function may be called before al_init or al_install_system.

See also: al_get_org_name, al_set_app_name

al_get_app_name

const char *al_get_app_name(void)

Returns the global application name string.

See also: al_set_app_name

al_get_org_name

const char *al_get_org_name(void)

Returns the global organization name string.

See also: al_set_org_name

al_get_system_driver

ALLEGRO_SYSTEM *al_get_system_driver(void)

Returns the currently active system driver, or NULL.

al_get_system_config

ALLEGRO_CONFIG *al_get_system_config(void)

Returns the current system configuration structure, or NULL if there is no active system driver. This is mainly used for configuring Allegro and its addons.

Allegro version 4.9.22 (WIP) - Last updated: 2010-09-26 11:48:26 UTC