DRAFT |
SDL_Init
Use this function to initialize the SDL library. This must be called before using any other SDL function.
Contents
Syntax
int SDL_Init(Uint32 flags)
Function Parameters
flags |
subsystem initialization flags; see Remarks for details |
Return Value
Returns 0 on success or -1 on failure; call SDL_GetError() for more information.
Code Examples
C
#include "SDL.h"
int main(int, char**) {
if (SDL_Init(SDL_INIT_VIDEO|SDL_INIT_TIMER) != 0) {
fprintf(stderr,
"\nUnable to initialize SDL: %s\n",
SDL_GetError()
);
return 1;
}
atexit(SDL_Quit);
/* ... */
return 0;
}
C++
#include <exception>
#include <string>
#include "SDL.h"
class InitError: public std::exception {
public:
InitError();
InitError(const std::string&);
virtual ~InitError() throw();
virtual const char* what() const throw();
private:
std::string msg;
};
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 Event Handling, File I/O, and Threading subsystems are initialized by default. To initialize other subsystems you must specifically call them. You can call SDL_Init(0) or SDL_Init(SDL_INIT_NOPARACHUTE) to initialize SDL without initializing any subsystems.
These are the flags which may be passed to SDL_Init() and may be OR'd together to initialize multiple subsystems.
SDL_INIT_TIMER |
timer subsystem |
SDL_INIT_AUDIO |
audio subsystem |
SDL_INIT_VIDEO |
video subsystem |
SDL_INIT_JOYSTICK |
joystick subsystem |
SDL_INIT_HAPTIC |
haptic (force feedback) subsystem |
SDL_INIT_EVERYTHING |
all of the above subsystems |
SDL_INIT_NOPARACHUTE |
don't catch fatal signals |
SDL_INIT_EVENTTHREAD |
run the event loop in a separate thread (not supported by all OSs) |
This function initializes the subsystems specified by flags. Unless the SDL_INIT_NOPARACHUTE flag is set, it will install cleanup signal handlers for some commonly ignored fatal signals (like SIGSEGV).
Note that the event system is actually started by the video subsystem, so using SDL_INIT_EVENTTHREAD without SDL_INIT_VIDEO is pointless.
*
Typical cause of this error The most common cause for error is using a particular display without having according the corresponding subsystem supported, such as missing a mouse driver when using <<Color2(green,using what? SDL? A mouse?)>> with a framebuffer green
device. In this case you can either compile SDL without a mouse device, or set the "SDL_NOMOUSE=1" environment variable before running your application.
*
