SDL/src/SDL.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2022 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_internal.h"

#if defined(__WIN32__) || defined(__GDK__)
#include "core/windows/SDL_windows.h"
#elif !defined(__WINRT__)
#include <unistd.h> /* _exit(), etc. */
#endif

/* this checks for HAVE_DBUS_DBUS_H internally. */
#include "core/linux/SDL_dbus.h"

#if defined(__EMSCRIPTEN__)
#include <emscripten.h>
#endif

/* Initialization code for SDL */

#include "SDL_assert_c.h"
#include "SDL_log_c.h"
#include "audio/SDL_audio_c.h"
#include "video/SDL_video_c.h"
#include "events/SDL_events_c.h"
#include "haptic/SDL_haptic_c.h"
#include "joystick/SDL_gamepad_c.h"
#include "joystick/SDL_joystick_c.h"
#include "sensor/SDL_sensor_c.h"

/* Initialization/Cleanup routines */
#if !SDL_TIMERS_DISABLED
#include "timer/SDL_timer_c.h"
#endif
#if SDL_VIDEO_DRIVER_WINDOWS
extern int SDL_HelperWindowCreate(void);
extern int SDL_HelperWindowDestroy(void);
#endif

#ifdef SDL_BUILD_MAJOR_VERSION
SDL_COMPILE_TIME_ASSERT(SDL_BUILD_MAJOR_VERSION,
                        SDL_MAJOR_VERSION == SDL_BUILD_MAJOR_VERSION);
SDL_COMPILE_TIME_ASSERT(SDL_BUILD_MINOR_VERSION,
                        SDL_MINOR_VERSION == SDL_BUILD_MINOR_VERSION);
SDL_COMPILE_TIME_ASSERT(SDL_BUILD_MICRO_VERSION,
                        SDL_PATCHLEVEL == SDL_BUILD_MICRO_VERSION);
#endif

SDL_COMPILE_TIME_ASSERT(SDL_MAJOR_VERSION_min, SDL_MAJOR_VERSION >= 0);
/* Limited only by the need to fit in SDL_version */
SDL_COMPILE_TIME_ASSERT(SDL_MAJOR_VERSION_max, SDL_MAJOR_VERSION <= 255);

SDL_COMPILE_TIME_ASSERT(SDL_MINOR_VERSION_min, SDL_MINOR_VERSION >= 0);
/* Limited only by the need to fit in SDL_version */
SDL_COMPILE_TIME_ASSERT(SDL_MINOR_VERSION_max, SDL_MINOR_VERSION <= 255);

SDL_COMPILE_TIME_ASSERT(SDL_PATCHLEVEL_min, SDL_PATCHLEVEL >= 0);
/* Limited by its encoding in SDL_VERSIONNUM and in the ABI versions */
SDL_COMPILE_TIME_ASSERT(SDL_PATCHLEVEL_max, SDL_PATCHLEVEL <= 99);

/* This is not declared in any header, although it is shared between some
    parts of SDL, because we don't want anything calling it without an
    extremely good reason. */
extern SDL_NORETURN void SDL_ExitProcess(int exitcode);
SDL_NORETURN void SDL_ExitProcess(int exitcode)
{
#if defined(__WIN32__) || defined(__GDK__)
    /* "if you do not know the state of all threads in your process, it is
       better to call TerminateProcess than ExitProcess"
       https://msdn.microsoft.com/en-us/library/windows/desktop/ms682658(v=vs.85).aspx */
    TerminateProcess(GetCurrentProcess(), exitcode);
    /* MingW doesn't have TerminateProcess marked as noreturn, so add an
       ExitProcess here that will never be reached but make MingW happy. */
    ExitProcess(exitcode);
#elif defined(__EMSCRIPTEN__)
    emscripten_cancel_main_loop();   /* this should "kill" the app. */
    emscripten_force_exit(exitcode); /* this should "kill" the app. */
    exit(exitcode);
#elif defined(__HAIKU__)  /* Haiku has _Exit, but it's not marked noreturn. */
    _exit(exitcode);
#elif defined(HAVE__EXIT) /* Upper case _Exit() */
    _Exit(exitcode);
#else
    _exit(exitcode);
#endif
}

/* The initialized subsystems */
#ifdef SDL_MAIN_NEEDED
static SDL_bool SDL_MainIsReady = SDL_FALSE;
#else
static SDL_bool SDL_MainIsReady = SDL_TRUE;
#endif
static SDL_bool SDL_bInMainQuit = SDL_FALSE;
static Uint8 SDL_SubsystemRefCount[32];

/* Private helper to increment a subsystem's ref counter. */
static void SDL_IncrementSubsystemRefCount(Uint32 subsystem)
{
    const int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    SDL_assert((subsystem_index < 0) || (SDL_SubsystemRefCount[subsystem_index] < 255));
    if (subsystem_index >= 0) {
        ++SDL_SubsystemRefCount[subsystem_index];
    }
}

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

/* Private helper to check if a system needs init. */
static SDL_bool SDL_ShouldInitSubsystem(Uint32 subsystem)
{
    const int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    SDL_assert((subsystem_index < 0) || (SDL_SubsystemRefCount[subsystem_index] < 255));
    return ((subsystem_index >= 0) && (SDL_SubsystemRefCount[subsystem_index] == 0)) ? SDL_TRUE : SDL_FALSE;
}

/* Private helper to check if a system needs to be quit. */
static SDL_bool SDL_ShouldQuitSubsystem(Uint32 subsystem)
{
    const int subsystem_index = SDL_MostSignificantBitIndex32(subsystem);
    if ((subsystem_index >= 0) && (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 (((subsystem_index >= 0) && (SDL_SubsystemRefCount[subsystem_index] == 1)) || SDL_bInMainQuit) ? SDL_TRUE : SDL_FALSE;
}

void SDL_SetMainReady(void)
{
    SDL_MainIsReady = SDL_TRUE;
}

int SDL_InitSubSystem(Uint32 flags)
{
    Uint32 flags_initialized = 0;

    if (!SDL_MainIsReady) {
        return SDL_SetError("Application didn't initialize properly, did you include SDL_main.h in the file containing your main() function?");
    }

    SDL_InitLog();

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

#if SDL_USE_LIBDBUS
    SDL_DBus_Init();
#endif

    if ((flags & SDL_INIT_GAMEPAD)) {
        /* game controller implies joystick */
        flags |= SDL_INIT_JOYSTICK;
    }

    if ((flags & (SDL_INIT_VIDEO | SDL_INIT_JOYSTICK | SDL_INIT_AUDIO))) {
        /* video or joystick or audio implies events */
        flags |= SDL_INIT_EVENTS;
    }

#if SDL_VIDEO_DRIVER_WINDOWS
    if ((flags & (SDL_INIT_HAPTIC | SDL_INIT_JOYSTICK))) {
        if (SDL_HelperWindowCreate() < 0) {
            goto quit_and_error;
        }
    }
#endif

#if !SDL_TIMERS_DISABLED
    SDL_InitTicks();
#endif

    /* Initialize the event subsystem */
    if ((flags & SDL_INIT_EVENTS)) {
#if !SDL_EVENTS_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_EVENTS)) {
            if (SDL_InitEvents() < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_EVENTS);
        flags_initialized |= SDL_INIT_EVENTS;
#else
        SDL_SetError("SDL not built with events support");
        goto quit_and_error;
#endif
    }

    /* Initialize the timer subsystem */
    if ((flags & SDL_INIT_TIMER)) {
#if !SDL_TIMERS_DISABLED && !SDL_TIMER_DUMMY
        if (SDL_ShouldInitSubsystem(SDL_INIT_TIMER)) {
            if (SDL_InitTimers() < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_TIMER);
        flags_initialized |= SDL_INIT_TIMER;
#else
        SDL_SetError("SDL not built with timer support");
        goto quit_and_error;
#endif
    }

    /* Initialize the video subsystem */
    if ((flags & SDL_INIT_VIDEO)) {
#if !SDL_VIDEO_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_VIDEO)) {
            if (SDL_VideoInit(NULL) < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_VIDEO);
        flags_initialized |= SDL_INIT_VIDEO;
#else
        SDL_SetError("SDL not built with video support");
        goto quit_and_error;
#endif
    }

    /* Initialize the audio subsystem */
    if ((flags & SDL_INIT_AUDIO)) {
#if !SDL_AUDIO_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_AUDIO)) {
            if (SDL_InitAudio(NULL) < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_AUDIO);
        flags_initialized |= SDL_INIT_AUDIO;
#else
        SDL_SetError("SDL not built with audio support");
        goto quit_and_error;
#endif
    }

    /* Initialize the joystick subsystem */
    if ((flags & SDL_INIT_JOYSTICK)) {
#if !SDL_JOYSTICK_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_JOYSTICK)) {
            if (SDL_InitJoysticks() < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_JOYSTICK);
        flags_initialized |= SDL_INIT_JOYSTICK;
#else
        SDL_SetError("SDL not built with joystick support");
        goto quit_and_error;
#endif
    }

    if ((flags & SDL_INIT_GAMEPAD)) {
#if !SDL_JOYSTICK_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_GAMEPAD)) {
            if (SDL_InitGamepads() < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_GAMEPAD);
        flags_initialized |= SDL_INIT_GAMEPAD;
#else
        SDL_SetError("SDL not built with joystick support");
        goto quit_and_error;
#endif
    }

    /* Initialize the haptic subsystem */
    if ((flags & SDL_INIT_HAPTIC)) {
#if !SDL_HAPTIC_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_HAPTIC)) {
            if (SDL_InitHaptics() < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_HAPTIC);
        flags_initialized |= SDL_INIT_HAPTIC;
#else
        SDL_SetError("SDL not built with haptic (force feedback) support");
        goto quit_and_error;
#endif
    }

    /* Initialize the sensor subsystem */
    if ((flags & SDL_INIT_SENSOR)) {
#if !SDL_SENSOR_DISABLED
        if (SDL_ShouldInitSubsystem(SDL_INIT_SENSOR)) {
            if (SDL_InitSensors() < 0) {
                goto quit_and_error;
            }
        }
        SDL_IncrementSubsystemRefCount(SDL_INIT_SENSOR);
        flags_initialized |= SDL_INIT_SENSOR;
#else
        SDL_SetError("SDL not built with sensor support");
        goto quit_and_error;
#endif
    }

    (void)flags_initialized; /* make static analysis happy, since this only gets used in error cases. */

    return 0;

quit_and_error:
    SDL_QuitSubSystem(flags_initialized);
    return -1;
}

int SDL_Init(Uint32 flags)
{
    return SDL_InitSubSystem(flags);
}

void SDL_QuitSubSystem(Uint32 flags)
{
    /* Shut down requested initialized subsystems */
#if !SDL_SENSOR_DISABLED
    if ((flags & SDL_INIT_SENSOR)) {
        if (SDL_ShouldQuitSubsystem(SDL_INIT_SENSOR)) {
            SDL_QuitSensors();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_SENSOR);
    }
#endif

#if !SDL_JOYSTICK_DISABLED
    if ((flags & SDL_INIT_GAMEPAD)) {
        /* game controller implies joystick */
        flags |= SDL_INIT_JOYSTICK;

        if (SDL_ShouldQuitSubsystem(SDL_INIT_GAMEPAD)) {
            SDL_QuitGamepads();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_GAMEPAD);
    }

    if ((flags & SDL_INIT_JOYSTICK)) {
        /* joystick implies events */
        flags |= SDL_INIT_EVENTS;

        if (SDL_ShouldQuitSubsystem(SDL_INIT_JOYSTICK)) {
            SDL_QuitJoysticks();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_JOYSTICK);
    }
#endif

#if !SDL_HAPTIC_DISABLED
    if ((flags & SDL_INIT_HAPTIC)) {
        if (SDL_ShouldQuitSubsystem(SDL_INIT_HAPTIC)) {
            SDL_QuitHaptics();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_HAPTIC);
    }
#endif

#if !SDL_AUDIO_DISABLED
    if ((flags & SDL_INIT_AUDIO)) {
        /* audio implies events */
        flags |= SDL_INIT_EVENTS;

        if (SDL_ShouldQuitSubsystem(SDL_INIT_AUDIO)) {
            SDL_QuitAudio();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_AUDIO);
    }
#endif

#if !SDL_VIDEO_DISABLED
    if ((flags & SDL_INIT_VIDEO)) {
        /* video implies events */
        flags |= SDL_INIT_EVENTS;

        if (SDL_ShouldQuitSubsystem(SDL_INIT_VIDEO)) {
            SDL_VideoQuit();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_VIDEO);
    }
#endif

#if !SDL_TIMERS_DISABLED && !SDL_TIMER_DUMMY
    if ((flags & SDL_INIT_TIMER)) {
        if (SDL_ShouldQuitSubsystem(SDL_INIT_TIMER)) {
            SDL_QuitTimers();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_TIMER);
    }
#endif

#if !SDL_EVENTS_DISABLED
    if ((flags & SDL_INIT_EVENTS)) {
        if (SDL_ShouldQuitSubsystem(SDL_INIT_EVENTS)) {
            SDL_QuitEvents();
        }
        SDL_DecrementSubsystemRefCount(SDL_INIT_EVENTS);
    }
#endif
}

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

    /* Fast path for checking one flag */
    if (SDL_HasExactlyOneBitSet32(flags)) {
        int subsystem_index = SDL_MostSignificantBitIndex32(flags);
        return SDL_SubsystemRefCount[subsystem_index] ? flags : 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 SDL_VIDEO_DRIVER_WINDOWS
    SDL_HelperWindowDestroy();
#endif
    SDL_QuitSubSystem(SDL_INIT_EVERYTHING);

#if !SDL_TIMERS_DISABLED
    SDL_QuitTicks();
#endif

    SDL_ClearHints();
    SDL_AssertionsQuit();

#if SDL_USE_LIBDBUS
    SDL_DBus_Quit();
#endif

    SDL_QuitLog();

    /* 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_TLSCleanup();

    SDL_bInMainQuit = SDL_FALSE;
}

/* Get the library version number */
void SDL_GetVersion(SDL_version *ver)
{
    static SDL_bool check_hint = SDL_TRUE;
    static SDL_bool legacy_version = SDL_FALSE;

    if (ver == NULL) {
        return;
    }

    SDL_VERSION(ver);

    if (check_hint) {
        check_hint = SDL_FALSE;
        legacy_version = SDL_GetHintBoolean("SDL_LEGACY_VERSION", SDL_FALSE);
    }

    if (legacy_version) {
        /* Prior to SDL 2.24.0, the patch version was incremented with every release */
        ver->patch = ver->minor;
        ver->minor = 0;
    }
}

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

/* Get the name of the platform */
const char *
SDL_GetPlatform(void)
{
#if defined(__AIX__)
    return "AIX";
#elif defined(__ANDROID__)
    return "Android";
#elif defined(__BSDI__)
    return "BSDI";
#elif defined(__DREAMCAST__)
    return "Dreamcast";
#elif defined(__EMSCRIPTEN__)
    return "Emscripten";
#elif defined(__FREEBSD__)
    return "FreeBSD";
#elif defined(__HAIKU__)
    return "Haiku";
#elif defined(__HPUX__)
    return "HP-UX";
#elif defined(__IRIX__)
    return "Irix";
#elif defined(__LINUX__)
    return "Linux";
#elif defined(__MINT__)
    return "Atari MiNT";
#elif defined(__MACOS__)
    return "macOS";
#elif defined(__NACL__)
    return "NaCl";
#elif defined(__NETBSD__)
    return "NetBSD";
#elif defined(__OPENBSD__)
    return "OpenBSD";
#elif defined(__OS2__)
    return "OS/2";
#elif defined(__OSF__)
    return "OSF/1";
#elif defined(__QNXNTO__)
    return "QNX Neutrino";
#elif defined(__RISCOS__)
    return "RISC OS";
#elif defined(__SOLARIS__)
    return "Solaris";
#elif defined(__WIN32__)
    return "Windows";
#elif defined(__WINRT__)
    return "WinRT";
#elif defined(__WINGDK__)
    return "WinGDK";
#elif defined(__XBOXONE__)
    return "Xbox One";
#elif defined(__XBOXSERIES__)
    return "Xbox Series X|S";
#elif defined(__IOS__)
    return "iOS";
#elif defined(__TVOS__)
    return "tvOS";
#elif defined(__PS2__)
    return "PlayStation 2";
#elif defined(__PSP__)
    return "PlayStation Portable";
#elif defined(__VITA__)
    return "PlayStation Vita";
#elif defined(__NGAGE__)
    return "Nokia N-Gage";
#elif defined(__3DS__)
    return "Nintendo 3DS";
#else
    return "Unknown (see SDL_platform.h)";
#endif
}

SDL_bool
SDL_IsTablet(void)
{
#if __ANDROID__
    extern SDL_bool SDL_IsAndroidTablet(void);
    return SDL_IsAndroidTablet();
#elif __IOS__
    extern SDL_bool SDL_IsIPad(void);
    return SDL_IsIPad();
#else
    return SDL_FALSE;
#endif
}

#if defined(__WIN32__)

#if (!defined(HAVE_LIBC) || defined(__WATCOMC__)) && !defined(SDL_STATIC_LIB)
/* Need to include DllMain() on Watcom C for some reason.. */

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 */

#endif /* defined(__WIN32__) || defined(__GDK__) */