(This is the documentation for SDL3, which is under heavy development and the API is changing! SDL2 is the current stable version!)

SDL_Init

Initialize the SDL library.

Header File

Defined in SDL_init.h, but apps should use #include <SDL3/SDL.h>

Syntax

int SDL_Init(Uint32 flags);

Function Parameters

flags

subsystem initialization flags

Return Value

Returns 0 on success or a negative error code 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_TIMER: timer subsystem
SDL_INIT_AUDIO: audio 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

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.

Version

This function is available since SDL 3.0.0.

Code Examples

#include <SDL3/SDL.h>

int main(int argc, char* argv[])
{
    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_AUDIO) != 0) {
        SDL_Log("Unable to initialize SDL: %s", SDL_GetError());
        return 1;
    }

    /* ... */

    SDL_Quit();

    return 0;
}