(This is the documentation for SDL3, which is the current stable version. SDL2 was the previous version!)

SDL_Init

Initialize the SDL library.

Header File

Syntax

bool SDL_Init(SDL_InitFlags flags);

Function Parameters

SDL_InitFlags

flags

subsystem initialization flags.

Return Value

(bool) Returns true on success or false on failure; call SDL_GetError() for more information.

Remarks

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_AUDIO: audio subsystem; automatically initializes the events subsystem
SDL_INIT_VIDEO: video subsystem; automatically initializes the events subsystem, should be initialized on the main thread.
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().

Version

This function is available since SDL 3.1.3.