SDL/include/SDL3/SDL_init.h

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2024 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/

/**
 * # CategoryInit
 *
 * SDL subsystem init and quit functions.
 */


#ifndef SDL_init_h_
#define SDL_init_h_

#include <SDL3/SDL_stdinc.h>
#include <SDL3/SDL_error.h>

#include <SDL3/SDL_begin_code.h>
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/* As of version 0.5, SDL is loaded dynamically into the application */

/**
 * Initialization flags for SDL_Init and/or SDL_InitSubSystem
 *
 * These are the flags which may be passed to SDL_Init(). You should specify
 * the subsystems which you will be using in your application.
 *
 * \since This datatype is available since SDL 3.0.0.
 *
 * \sa SDL_Init
 * \sa SDL_Quit
 * \sa SDL_InitSubSystem
 * \sa SDL_QuitSubSystem
 * \sa SDL_WasInit
 */
typedef Uint32 SDL_InitFlags;

#define SDL_INIT_TIMER      0x00000001u
#define SDL_INIT_AUDIO      0x00000010u /**< `SDL_INIT_AUDIO` implies `SDL_INIT_EVENTS` */
#define SDL_INIT_VIDEO      0x00000020u /**< `SDL_INIT_VIDEO` implies `SDL_INIT_EVENTS` */
#define SDL_INIT_JOYSTICK   0x00000200u /**< `SDL_INIT_JOYSTICK` implies `SDL_INIT_EVENTS`, should be initialized on the same thread as SDL_INIT_VIDEO on Windows if you don't set SDL_HINT_JOYSTICK_THREAD */
#define SDL_INIT_HAPTIC     0x00001000u
#define SDL_INIT_GAMEPAD    0x00002000u /**< `SDL_INIT_GAMEPAD` implies `SDL_INIT_JOYSTICK` */
#define SDL_INIT_EVENTS     0x00004000u
#define SDL_INIT_SENSOR     0x00008000u /**< `SDL_INIT_SENSOR` implies `SDL_INIT_EVENTS` */
#define SDL_INIT_CAMERA     0x00010000u /**< `SDL_INIT_CAMERA` implies `SDL_INIT_EVENTS` */

/**
 * Return values for optional main callbacks.
 *
 * See
 * https://wiki.libsdl.org/SDL3/README/main-functions#main-callbacks-in-sdl3
 * for details.
 *
 * \since This enum is available since SDL 3.0.0.
 */
typedef enum SDL_AppResult
{
    SDL_APP_CONTINUE,   /** Value that requests that the app continue from the main callbacks. If SDL_AppInit, SDL_AppEvent, or SDL_AppIterate returns this value, the program will continue to run. */
    SDL_APP_SUCCESS,    /** Value that requests termination with success from the main callbacks. If SDL_AppInit, SDL_AppEvent, or SDL_AppIterate returns this value, the program will terminate and report success to the operating system. What that success looks like is platform-dependent. On Unix, for example, the process error code will be zero. */
    SDL_APP_FAILURE     /** Value that requests termination with error from the main callbacks. If SDL_AppInit, SDL_AppEvent, or SDL_AppIterate returns this value, the program will terminate and report failure to the operating system. What that failure looks like is platform-dependent. On Unix, for example, the process error code will be non-zero. */
} SDL_AppResult;

typedef SDL_AppResult (SDLCALL *SDL_AppInit_func)(void **appstate, int argc, char *argv[]);
typedef SDL_AppResult (SDLCALL *SDL_AppIterate_func)(void *appstate);
typedef SDL_AppResult (SDLCALL *SDL_AppEvent_func)(void *appstate, const SDL_Event *event);
typedef void (SDLCALL *SDL_AppQuit_func)(void *appstate);

/**
 * Initialize the SDL library.
 *
 * SDL_Init() simply forwards to calling SDL_InitSubSystem(). Therefore, the
 * two may be used interchangeably. Though for readability of your code
 * SDL_InitSubSystem() might be preferred.
 *
 * The file I/O (for example: SDL_IOFromFile) and threading (SDL_CreateThread)
 * subsystems are initialized by default. Message boxes
 * (SDL_ShowSimpleMessageBox) also attempt to work without initializing the
 * video subsystem, in hopes of being useful in showing an error dialog when
 * SDL_Init fails. You must specifically initialize other subsystems if you
 * use them in your application.
 *
 * Logging (such as SDL_Log) works without initialization, too.
 *
 * `flags` may be any of the following OR'd together:
 *
 * - `SDL_INIT_TIMER`: timer subsystem
 * - `SDL_INIT_AUDIO`: audio subsystem; automatically initializes the events
 *   subsystem
 * - `SDL_INIT_VIDEO`: video subsystem; automatically initializes the events
 *   subsystem
 * - `SDL_INIT_JOYSTICK`: joystick subsystem; automatically initializes the
 *   events subsystem
 * - `SDL_INIT_HAPTIC`: haptic (force feedback) subsystem
 * - `SDL_INIT_GAMEPAD`: gamepad subsystem; automatically initializes the
 *   joystick subsystem
 * - `SDL_INIT_EVENTS`: events subsystem
 * - `SDL_INIT_SENSOR`: sensor subsystem; automatically initializes the events
 *   subsystem
 * - `SDL_INIT_CAMERA`: camera subsystem; automatically initializes the events
 *   subsystem
 *
 * Subsystem initialization is ref-counted, you must call SDL_QuitSubSystem()
 * for each SDL_InitSubSystem() to correctly shutdown a subsystem manually (or
 * call SDL_Quit() to force shutdown). If a subsystem is already loaded then
 * this call will increase the ref-count and return.
 *
 * Consider reporting some basic metadata about your application before
 * calling SDL_Init, using either SDL_SetAppMetadata() or
 * SDL_SetAppMetadataProperty().
 *
 * \param flags subsystem initialization flags.
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_SetAppMetadata
 * \sa SDL_SetAppMetadataProperty
 * \sa SDL_InitSubSystem
 * \sa SDL_Quit
 * \sa SDL_SetMainReady
 * \sa SDL_WasInit
 */
extern SDL_DECLSPEC int SDLCALL SDL_Init(SDL_InitFlags flags);

/**
 * Compatibility function to initialize the SDL library.
 *
 * This function and SDL_Init() are interchangeable.
 *
 * \param flags any of the flags used by SDL_Init(); see SDL_Init for details.
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_Init
 * \sa SDL_Quit
 * \sa SDL_QuitSubSystem
 */
extern SDL_DECLSPEC int SDLCALL SDL_InitSubSystem(SDL_InitFlags flags);

/**
 * Shut down specific SDL subsystems.
 *
 * You still need to call SDL_Quit() even if you close all open subsystems
 * with SDL_QuitSubSystem().
 *
 * \param flags any of the flags used by SDL_Init(); see SDL_Init for details.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_InitSubSystem
 * \sa SDL_Quit
 */
extern SDL_DECLSPEC void SDLCALL SDL_QuitSubSystem(SDL_InitFlags flags);

/**
 * Get a mask of the specified subsystems which are currently initialized.
 *
 * \param flags any of the flags used by SDL_Init(); see SDL_Init for details.
 * \returns a mask of all initialized subsystems if `flags` is 0, otherwise it
 *          returns the initialization status of the specified subsystems.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_Init
 * \sa SDL_InitSubSystem
 */
extern SDL_DECLSPEC SDL_InitFlags SDLCALL SDL_WasInit(SDL_InitFlags flags);

/**
 * Clean up all initialized subsystems.
 *
 * You should call this function even if you have already shutdown each
 * initialized subsystem with SDL_QuitSubSystem(). It is safe to call this
 * function even in the case of errors in initialization.
 *
 * You can use this function with atexit() to ensure that it is run when your
 * application is shutdown, but it is not wise to do this from a library or
 * other dynamically loaded code.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_Init
 * \sa SDL_QuitSubSystem
 */
extern SDL_DECLSPEC void SDLCALL SDL_Quit(void);

/**
 * Specify basic metadata about your app.
 *
 * You can optionally provide metadata about your app to SDL. This is not
 * required, but strongly encouraged.
 *
 * There are several locations where SDL can make use of metadata (an "About"
 * box in the macOS menu bar, the name of the app can be shown on some audio
 * mixers, etc). Any piece of metadata can be left as NULL, if a specific
 * detail doesn't make sense for the app.
 *
 * This function should be called as early as possible, before SDL_Init.
 * Multiple calls to this function are allowed, but various state might not
 * change once it has been set up with a previous call to this function.
 *
 * Passing a NULL removes any previous metadata.
 *
 * This is a simplified interface for the most important information. You can
 * supply significantly more detailed metadata with
 * SDL_SetAppMetadataProperty().
 *
 * \param appname The name of the application ("My Game 2: Bad Guy's
 *                Revenge!").
 * \param appversion The version of the application ("1.0.0beta5" or a git
 *                   hash, or whatever makes sense).
 * \param appidentifier A unique string in reverse-domain format that
 *                      identifies this app ("com.example.mygame2").
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \threadsafety It is safe to call this function from any thread.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_SetAppMetadataProperty
 */
extern SDL_DECLSPEC int SDLCALL SDL_SetAppMetadata(const char *appname, const char *appversion, const char *appidentifier);

/**
 * Specify metadata about your app through a set of properties.
 *
 * You can optionally provide metadata about your app to SDL. This is not
 * required, but strongly encouraged.
 *
 * There are several locations where SDL can make use of metadata (an "About"
 * box in the macOS menu bar, the name of the app can be shown on some audio
 * mixers, etc). Any piece of metadata can be left out, if a specific detail
 * doesn't make sense for the app.
 *
 * This function should be called as early as possible, before SDL_Init.
 * Multiple calls to this function are allowed, but various state might not
 * change once it has been set up with a previous call to this function.
 *
 * Once set, this metadata can be read using SDL_GetMetadataProperty().
 *
 * These are the supported properties:
 *
 * - `SDL_PROP_APP_METADATA_NAME_STRING`: The human-readable name of the
 *   application, like "My Game 2: Bad Guy's Revenge!". This will show up
 *   anywhere the OS shows the name of the application separately from window
 *   titles, such as volume control applets, etc. This defaults to "SDL
 *   Application".
 * - SDL_PROP_APP_METADATA_VERSION_STRING`: The version of the app that is
 *   running; there are no rules on format, so "1.0.3beta2" and "April 22nd,
 *   2024" and a git hash are all valid options. This has no default.
 * - `SDL_PROP_APP_METADATA_IDENTIFIER_STRING`: A unique string that
 *   identifies this app. This must be in reverse-domain format, like
 *   "com.example.mygame2". This string is used by desktop compositors to
 *   identify and group windows together, as well as match applications with
 *   associated desktop settings and icons. If you plan to package your
 *   application in a container such as Flatpak, the app ID should match the
 *   name of your Flatpak container as well. This has no default.
 * - SDL_PROP_APP_METADATA_CREATOR_STRING`: The human-readable name of the
 *   creator/developer/maker of this app, like "MojoWorkshop, LLC"
 * - SDL_PROP_APP_METADATA_COPYRIGHT_STRING`: The human-readable copyright
 *   notice, like "Copyright (c) 2024 MojoWorkshop, LLC" or whatnot. Keep this
 *   to one line, don't paste a copy of a whole software license in here. This
 *   has no default.
 * - SDL_PROP_APP_METADATA_URL_STRING`: A URL to the app on the web. Maybe a
 *   product page, or a storefront, or even a GitHub repository, for user's
 *   further information This has no default.
 * - SDL_PROP_APP_METADATA_TYPE_STRING`: The type of application this is.
 *   Currently this string can be "game" for a video game, "mediaplayer" for a
 *   media player, or generically "application" if nothing else applies.
 *   Future versions of SDL might add new types. This defaults to
 *   "application".
 *
 * \param name the name of the metadata property to set.
 * \param value the value of the property, or NULL to remove that property.
 * \returns 0 on success or a negative error code on failure; call
 *          SDL_GetError() for more information.
 *
 * \threadsafety It is safe to call this function from any thread.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_GetAppMetadataProperty
 * \sa SDL_SetAppMetadata
 */
extern SDL_DECLSPEC int SDLCALL SDL_SetAppMetadataProperty(const char *name, const char *value);

#define SDL_PROP_APP_METADATA_NAME_STRING         "SDL.app.metadata.name"
#define SDL_PROP_APP_METADATA_VERSION_STRING      "SDL.app.metadata.version"
#define SDL_PROP_APP_METADATA_IDENTIFIER_STRING   "SDL.app.metadata.identifier"
#define SDL_PROP_APP_METADATA_CREATOR_STRING      "SDL.app.metadata.creator"
#define SDL_PROP_APP_METADATA_COPYRIGHT_STRING    "SDL.app.metadata.copyright"
#define SDL_PROP_APP_METADATA_URL_STRING          "SDL.app.metadata.url"
#define SDL_PROP_APP_METADATA_TYPE_STRING         "SDL.app.metadata.type"

/**
 * Get metadata about your app.
 *
 * This returns metadata previously set using SDL_SetAppMetadata() or
 * SDL_SetAppMetadataProperty(). See SDL_SetAppMetadataProperty() for the list
 * of available properties and their meanings.
 *
 * \param name the name of the metadata property to get.
 * \returns the current value of the metadata property, or the default if it
 *          is not set, NULL for properties with no default.
 *
 * \threadsafety It is safe to call this function from any thread, although
 *               the string returned is not protected and could potentially be
 *               freed if you call SDL_SetAppMetadataProperty() to set that
 *               property from another thread.
 *
 * \since This function is available since SDL 3.0.0.
 *
 * \sa SDL_SetAppMetadata
 * \sa SDL_SetAppMetadataProperty
 */
extern SDL_DECLSPEC const char * SDLCALL SDL_GetAppMetadataProperty(const char *name);

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include <SDL3/SDL_close_code.h>

#endif /* SDL_init_h_ */