src/SDL.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2012 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.
*/
#include "SDL_config.h"

/* Initialization code for SDL */

#include "SDL.h"
#include "SDL_bits.h"
#include "SDL_revision.h"
#include "SDL_fatal.h"
#include "SDL_assert_c.h"
#include "haptic/SDL_haptic_c.h"
#include "joystick/SDL_joystick_c.h"

/* Initialization/Cleanup routines */
#if !SDL_TIMERS_DISABLED
extern void SDL_StartTicks(void);
extern int SDL_TimerInit(void);
extern void SDL_TimerQuit(void);
#endif
#if defined(__WIN32__)
extern int SDL_HelperWindowCreate(void);
extern int SDL_HelperWindowDestroy(void);
#endif


/* The initialized subsystems */
static Uint32 ticks_started = 0;
static SDL_bool SDL_bInMainQuit = SDL_FALSE;
static Uint8 SDL_SubsystemRefCount[ 32 ];

/* Private helper to increment a subsystem's ref counter. */
static void SDL_PrivateSubsystemRefCountIncr(Uint32 subsystem)
{
    int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    SDL_assert(SDL_SubsystemRefCount[subsystem_index] < 255);
    ++SDL_SubsystemRefCount[subsystem_index];
}

/* Private helper to decrement a subsystem's ref counter. */
void SDL_PrivateSubsystemRefCountDecr(Uint32 subsystem)
{
    int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    if (SDL_SubsystemRefCount[subsystem_index] > 0) {
        --SDL_SubsystemRefCount[subsystem_index];
    }
}

/* Private helper to check if a system needs init. */
static SDL_bool
SDL_PrivateShouldInitSubsystem(Uint32 flags, Uint32 subsystem)
{
    if ((flags & subsystem) == 0) {
      return SDL_FALSE;
    }

    int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    SDL_assert(SDL_SubsystemRefCount[subsystem_index] < 255);
    return (SDL_SubsystemRefCount[subsystem_index] == 0);
}

/* Private helper to check if a system needs to be quit. */
static SDL_bool
SDL_PrivateShouldQuitSubsystem(Uint32 subsystem) {
    int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    if (SDL_SubsystemRefCount[subsystem_index] == 0) {
      return SDL_FALSE;
    }

    /* If we're in SDL_Quit, we shut down every subsystem, even if refcount
     * isn't zero.
     */
    return SDL_SubsystemRefCount[subsystem_index] == 1 || SDL_bInMainQuit;
}

int
SDL_InitSubSystem(Uint32 flags)
{
#if !SDL_TIMERS_DISABLED
    if (!ticks_started) {
        SDL_StartTicks();
        ticks_started = 1;
    }
#endif

    /* Initialize the timer subsystem */
    if (SDL_PrivateShouldInitSubsystem(flags, SDL_INIT_TIMER)) {
#if !SDL_TIMERS_DISABLED
        if (SDL_TimerInit() < 0) {
            return (-1);
        }
        SDL_PrivateSubsystemRefCountIncr(SDL_INIT_TIMER);
#else
        SDL_SetError("SDL not built with timer support");
        return (-1);
#endif
    }

    /* Initialize the video/event subsystem */
    if (SDL_PrivateShouldInitSubsystem(flags, SDL_INIT_VIDEO)) {
#if !SDL_VIDEO_DISABLED
        if (SDL_VideoInit(NULL) < 0) {
            return (-1);
        }
        SDL_PrivateSubsystemRefCountIncr(SDL_INIT_VIDEO);
#else
        SDL_SetError("SDL not built with video support");
        return (-1);
#endif
    }

    /* Initialize the audio subsystem */
    if (SDL_PrivateShouldInitSubsystem(flags, SDL_INIT_AUDIO)) {
#if !SDL_AUDIO_DISABLED
        if (SDL_AudioInit(NULL) < 0) {
            return (-1);
        }
        SDL_PrivateSubsystemRefCountIncr(SDL_INIT_AUDIO);
#else
        SDL_SetError("SDL not built with audio support");
        return (-1);
#endif
    }

    if ((flags & SDL_INIT_GAMECONTROLLER)) {
        // Game controller implies Joystick.
        flags |= SDL_INIT_JOYSTICK;
    }

    /* Initialize the joystick subsystem */
    if (SDL_PrivateShouldInitSubsystem(flags, SDL_INIT_JOYSTICK)) {
#if !SDL_JOYSTICK_DISABLED
        if (SDL_JoystickInit() < 0) {
            return (-1);
        }
        SDL_PrivateSubsystemRefCountIncr(SDL_INIT_JOYSTICK);
#else
        SDL_SetError("SDL not built with joystick support");
        return (-1);
#endif
    }

    if (SDL_PrivateShouldInitSubsystem(flags, SDL_INIT_GAMECONTROLLER)) {
#if !SDL_JOYSTICK_DISABLED
        if (SDL_GameControllerInit() < 0) {
            return (-1);
        }
        SDL_PrivateSubsystemRefCountIncr(SDL_INIT_GAMECONTROLLER);
#else
        SDL_SetError("SDL not built with joystick support");
        return (-1);
#endif
    }

    /* Initialize the haptic subsystem */
    if (SDL_PrivateShouldInitSubsystem(flags, SDL_INIT_HAPTIC)) {
#if !SDL_HAPTIC_DISABLED
        if (SDL_HapticInit() < 0) {
            return (-1);
        }
        SDL_PrivateSubsystemRefCountIncr(SDL_INIT_HAPTIC);
#else
        SDL_SetError("SDL not built with haptic (force feedback) support");
        return (-1);
#endif
    }

    return (0);
}

int
SDL_Init(Uint32 flags)
{
    if (SDL_AssertionsInit() < 0) {
        return -1;
    }

    /* Clear the error message */
    SDL_ClearError();

#if defined(__WIN32__)
    if (SDL_HelperWindowCreate() < 0) {
        return -1;
    }
#endif

    /* Initialize the desired subsystems */
    if (SDL_InitSubSystem(flags) < 0) {
        return (-1);
    }

    /* Everything is initialized */
    if (!(flags & SDL_INIT_NOPARACHUTE)) {
        SDL_InstallParachute();
    }

    return (0);
}

void
SDL_QuitSubSystem(Uint32 flags)
{
    /* Shut down requested initialized subsystems */
#if !SDL_JOYSTICK_DISABLED
    if ((flags & SDL_INIT_GAMECONTROLLER)) {
        // Game controller implies Joystick.
        flags |= SDL_INIT_JOYSTICK;

        if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_GAMECONTROLLER)) {
            SDL_GameControllerQuit();
		}
        SDL_PrivateSubsystemRefCountDecr(SDL_INIT_GAMECONTROLLER);
    }

    if ((flags & SDL_INIT_JOYSTICK)) {
        if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_JOYSTICK)) {
			SDL_JoystickQuit();
		}
        SDL_PrivateSubsystemRefCountDecr(SDL_INIT_JOYSTICK);
    }
#endif

#if !SDL_HAPTIC_DISABLED
    if ((flags & SDL_INIT_HAPTIC)) {
        if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_HAPTIC)) {
			SDL_HapticQuit();
		}
        SDL_PrivateSubsystemRefCountDecr(SDL_INIT_HAPTIC);
    }
#endif

#if !SDL_AUDIO_DISABLED
    if ((flags & SDL_INIT_AUDIO)) {
        if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_AUDIO)) {
			SDL_AudioQuit();
		}
        SDL_PrivateSubsystemRefCountDecr(SDL_INIT_AUDIO);
    }
#endif

#if !SDL_VIDEO_DISABLED
    if ((flags & SDL_INIT_VIDEO)) {
        if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_VIDEO)) {
			SDL_VideoQuit();
		}
        SDL_PrivateSubsystemRefCountDecr(SDL_INIT_VIDEO);
    }
#endif

#if !SDL_TIMERS_DISABLED
    if ((flags & SDL_INIT_TIMER)) {
        if (SDL_PrivateShouldQuitSubsystem(SDL_INIT_TIMER)) {
			SDL_TimerQuit();
		}
        SDL_PrivateSubsystemRefCountDecr(SDL_INIT_TIMER);
    }
#endif
}

Uint32
SDL_WasInit(Uint32 flags)
{
    int i;
    int num_subsystems = SDL_arraysize(SDL_SubsystemRefCount);
    Uint32 initialized = 0;

    if (!flags) {
        flags = SDL_INIT_EVERYTHING;
    }

    num_subsystems = SDL_min(num_subsystems, SDL_MostSignificantBitIndex32(flags) + 1);

    /* Iterate over each bit in flags, and check the matching subsystem. */
    for (i = 0; i < num_subsystems; ++i) {
        if ((flags & 1) && SDL_SubsystemRefCount[i] > 0) {
            initialized |= (1 << i);
        }

        flags >>= 1;
    }

    return initialized;
}

void
SDL_Quit(void)
{
    SDL_bInMainQuit = SDL_TRUE;

    /* Quit all subsystems */
#if defined(__WIN32__)
    SDL_HelperWindowDestroy();
#endif
    SDL_QuitSubSystem(SDL_INIT_EVERYTHING);

    /* Uninstall any parachute signal handlers */
    SDL_UninstallParachute();

    SDL_ClearHints();
    SDL_AssertionsQuit();
    SDL_LogResetPriorities();

    /* Now that every subsystem has been quit, we reset the subsystem refcount
     * and the list of initialized subsystems.
     */
    SDL_memset( SDL_SubsystemRefCount, 0x0, sizeof(SDL_SubsystemRefCount) );

    SDL_bInMainQuit = SDL_FALSE;
}

/* Get the library version number */
void
SDL_GetVersion(SDL_version * ver)
{
    SDL_VERSION(ver);
}

/* Get the library source revision */
const char *
SDL_GetRevision(void)
{
    return SDL_REVISION;
}

/* Get the library source revision number */
int
SDL_GetRevisionNumber(void)
{
    return SDL_REVISION_NUMBER;
}

/* Get the name of the platform */
const char *
SDL_GetPlatform()
{
#if __AIX__
    return "AIX";
#elif __ANDROID__
    return "Android";
#elif __HAIKU__
/* Haiku must appear here before BeOS, since it also defines __BEOS__ */
    return "Haiku";
#elif __BEOS__
    return "BeOS";
#elif __BSDI__
    return "BSDI";
#elif __DREAMCAST__
    return "Dreamcast";
#elif __FREEBSD__
    return "FreeBSD";
#elif __HPUX__
    return "HP-UX";
#elif __IRIX__
    return "Irix";
#elif __LINUX__
    return "Linux";
#elif __MINT__
    return "Atari MiNT";
#elif __MACOS__
    return "MacOS Classic";
#elif __MACOSX__
    return "Mac OS X";
#elif __NETBSD__
    return "NetBSD";
#elif __NDS__
    return "Nintendo DS";
#elif __OPENBSD__
    return "OpenBSD";
#elif __OS2__
    return "OS/2";
#elif __OSF__
    return "OSF/1";
#elif __QNXNTO__
    return "QNX Neutrino";
#elif __RISCOS__
    return "RISC OS";
#elif __SOLARIS__
    return "Solaris";
#elif __WIN32__
    return "Windows";
#elif __IPHONEOS__
    return "iPhone OS";
#else
    return "Unknown (see SDL_platform.h)";
#endif
}

#if defined(__WIN32__)

#if !defined(HAVE_LIBC) || (defined(__WATCOMC__) && defined(BUILD_DLL))
/* Need to include DllMain() on Watcom C for some reason.. */
#include "core/windows/SDL_windows.h"

BOOL APIENTRY
_DllMainCRTStartup(HANDLE hModule,
                   DWORD ul_reason_for_call, LPVOID lpReserved)
{
    switch (ul_reason_for_call) {
    case DLL_PROCESS_ATTACH:
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:
        break;
    }
    return TRUE;
}
#endif /* building DLL with Watcom C */

#endif /* __WIN32__ */

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