Differences between revisions 31 and 52 (spanning 21 versions)

SDL_Init

Use this function to initialize the SDL library. This must be called before using most other SDL functions.

Contents

SDL_Init

Syntax

int SDL_Init(Uint32 flags)

Function Parameters

flags

subsystem initialization flags; see Remarks for details

Return Value

Returns 0 on success or a negative error code on failure; call SDL_GetError() for more information.

Code Examples

#include "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;
}

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 and threading subsystems are initialized by default. You must specifically initialize other subsystems if you use them in your application.

Logging 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_GAMECONTROLLER	controller subsystem; automatically initializes the joystick subsystem
SDL_INIT_EVENTS	events subsystem
SDL_INIT_EVERYTHING	all of the above subsystems
SDL_INIT_NOPARACHUTE	compatibility; this flag is ignored

If you want to initialize subsystems separately you would call SDL_Init(0) followed by SDL_InitSubSystem() with the desired subsystem flag.

Related Functions

CategoryAPI, CategoryInit

-  ⇤ ← Revision 31 as of 2013-08-10 04:17:44 → 
  Size: 3327
  Editor: Sam Lantinga
  Comment: Use the right pragma to disable camelcase
+   ← Revision 52 as of 2017-04-08 21:22:04 → ⇥
  Size: 2484
  Editor: PhilippWiesemann
  Comment: Fixed description, see Remarks.
-Deletions are marked like this.
+Additions are marked like this.
 Line 5:
-Use this function to initialize the SDL library.  This must be called before using any other SDL function.
+Use this function to initialize the SDL library.  This must be called before using most other SDL functions.
 Line 21:
-=== C ===
-Line 25:
+Line 24:
-int main(int, char**)  {
    if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0) {
        fprintf(stderr, 
                "\nUnable to initialize SDL:  %s\n",                  SDL_GetError()
               );
+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());
-Line 33:
+Line 30:
-    atexit(SDL_Quit);
-Line 36:
+Line 32:
+    SDL_Quit();
-Line 41:
+Line 39:
-=== C++ ===
{{{#!highlight cpp
#include <exception>
#include <string>
#include "SDL.h"
+== 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.
-Line 47:
+Line 42:
-class InitError: public std::exception {
    public:
        InitError();
        InitError(const std::string&);
        virtual ~InitError() throw();
        virtual const char* what() const throw();
    private:
        std::string msg;
};
+The [[CategoryIO|file I/O]] and [[CategoryThread|threading]] subsystems are initialized by default.  You must specifically initialize other subsystems if you use them in your application.
-Line 57:
+Line 44:
-InitError::InitError():
  exception(), msg(SDL_GetError()) {}
InitError::InitError(const std::string& m):
  exception(), msg(m) {}
InitError::~InitError() throw() {}
const char* InitError::what() const throw() {
    return msg.c_str();
}

class SDL {
    public:
        SDL(Uint32 flags = 0) throw(InitError);
        virtual ~SDL();
};

SDL::SDL(Uint32 flags) throw(InitError) {
    if (SDL_Init(flags) != 0)
        throw InitError();
}

SDL::~SDL() {
    SDL_Quit();
}

/* ... */

#include <iostream>

int main(int argc, char **argv) {
    try {
        SDL sdl(SDL_INIT_VIDEO|SDL_INIT_TIMER);

        /* ... */

        return 0;
    }

    catch (const InitError& err) {
        std::cerr
            << "Error while initializing SDL:  " 
            << err.what() << std::endl;
    }
    
    return 1;
}
}}}

== Remarks ==
The [[CategoryEvents|Event Handling]], [[CategoryIO|File I/O]], and [[CategoryThread|Threading]] subsystems are initialized by default.  You must specifically initialize other subsystems if you use them in your application.
+[[CategoryLog|Logging]] works without initialization, too.
-Line 109:
+Line 48:
+##The following content is included on `SDL_InitSubSystem`.  Any changes between these comments will be reflected there as well.  Please use caution when editing.  Start Include here.
-Line 111:
+Line 52:
-||'''SDL_INIT_VIDEO'''||video subsystem||
||'''SDL_INIT_JOYSTICK'''||joystick subsystem||
+||'''SDL_INIT_VIDEO'''||video subsystem; automatically initializes the events subsystem||
||'''SDL_INIT_JOYSTICK'''||joystick subsystem; automatically initializes the events subsystem||
-Line 114:
+Line 55:
-||'''SDL_INIT_GAMECONTROLLER'''||controller subsystem||
+||'''SDL_INIT_GAMECONTROLLER'''||controller subsystem; automatically initializes the joystick subsystem||
-Line 117:
+Line 58:
-||'''SDL_INIT_NOPARACHUTE'''||don't catch fatal signals||
+||'''SDL_INIT_NOPARACHUTE'''||compatibility; this flag is ignored||
-Line 119:
+Line 60:
-Unless the SDL_INIT_NOPARACHUTE flag is set, it will install cleanup signal handlers for some commonly ignored fatal signals (like SIGSEGV).
+##End Include here.
-Line 124:
+Line 65:
- .[[SDL_InitSubSystem]] 
 .[[SDL_Quit]]   .[[SDL_WasInit]] 
 .[[SDL_SetMainReady]]
+ .[[SDL_InitSubSystem]]
 .[[SDL_Quit]]
 .[[SDL_SetMainReady]]
 .[[SDL_WasInit]]

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