Hooks-windows.cpp

/*
https://github.com/peterix/dfhack
Copyright (c) 2009-2012 Petr Mrázek (peterix@gmail.com)

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.
*/

#define DFhackCExport extern "C" __declspec(dllexport)

#include <windows.h>
#include <stdint.h>
#include <vector>
#include <string>
#include "Core.h"
#include "Hooks.h"
#include <stdio.h>

#include "tinythread.h"
#include "modules/Graphic.h"

/*************************************************************************/
// extremely boring wrappers beyond this point. Only fix when broken

// we don't know which of the SDL functions will be called first... so we
// just catch the first one and init all our function pointers at that time
bool FirstCall(void);
bool inited = false;

/// wrappers for SDL 1.2 functions used in 40d16
/***** Condition variables

SDL_CreateCond
    SDL_cond * SDLCALL SDL_CreateCond(void);
SDL_CondSignal
    int SDLCALL SDL_CondSignal(SDL_cond *cond);
SDL_CondWait
    int SDLCALL SDL_CondWait(SDL_cond *cond, SDL_mutex *mut);
SDL_DestroyCond
    void SDLCALL SDL_DestroyCond(SDL_cond *cond);
*/
static vPtr (*_SDL_CreateCond)() = 0;
DFhackCExport vPtr SDL_CreateCond()
{
    return _SDL_CreateCond();
}

static int (*_SDL_CondSignal)( vPtr ) = 0;
DFhackCExport int SDL_CondSignal( vPtr cond )
{
    return _SDL_CondSignal(cond);
}

static int (*_SDL_CondWait)( vPtr,vPtr ) = 0;
DFhackCExport int SDL_CondWait( vPtr cond, vPtr mutex )
{
    return _SDL_CondWait(cond, mutex);
}

static void (*_SDL_DestroyCond)( vPtr ) = 0;
DFhackCExport void SDL_DestroyCond( vPtr cond )
{
    _SDL_DestroyCond(cond);
}

/***** mutexes

SDL_CreateMutex
    SDL_mutex * SDLCALL SDL_CreateMutex(void);
SDL_mutexP
    int SDLCALL SDL_mutexP(SDL_mutex *mutex);
SDL_DestroyMutex
    void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex);
*/
static vPtr (*_SDL_CreateMutex)(void) = 0;
DFhackCExport vPtr SDL_CreateMutex(void)
{
    return _SDL_CreateMutex();
}

static int (*_SDL_mutexP)(vPtr mutex) = 0;
DFhackCExport int SDL_mutexP(vPtr mutex)
{
    return _SDL_mutexP(mutex);
}

static int (*_SDL_mutexV)(vPtr mutex) = 0;
DFhackCExport int SDL_mutexV(vPtr mutex)
{
    return _SDL_mutexV(mutex);
}

static void (*_SDL_DestroyMutex)(vPtr mutex) = 0;
DFhackCExport void SDL_DestroyMutex(vPtr mutex)
{
    _SDL_DestroyMutex(mutex);
}


/***** timers

SDL_AddTimer
    SDL_TimerID SDLCALL SDL_AddTimer(Uint32 interval, SDL_NewTimerCallback callback, void *param);
SDL_RemoveTimer
    SDL_bool SDLCALL SDL_RemoveTimer(SDL_TimerID t);
SDL_GetTicks
    Uint32 SDLCALL SDL_GetTicks(void);
*/
static vPtr (*_SDL_AddTimer)(uint32_t interval, fPtr callback, vPtr param) = 0;
DFhackCExport vPtr SDL_AddTimer(uint32_t interval, fPtr callback, vPtr param)
{
    return _SDL_AddTimer(interval, callback, param);
}

static bool (*_SDL_RemoveTimer)(vPtr timer) = 0;
DFhackCExport bool SDL_RemoveTimer(vPtr timer)
{
    return _SDL_RemoveTimer(timer);
}

static uint32_t (*_SDL_GetTicks)(void) = 0;
DFhackCExport uint32_t SDL_GetTicks(void)
{
    return _SDL_GetTicks();
}

/***** Surfaces
SDL_CreateRGBSurface
    SDL_Surface * SDLCALL SDL_CreateRGBSurface
        (Uint32 flags, int width, int height, int depth, 
        Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);

SDL_CreateRGBSurfaceFrom
    SDL_Surface * SDLCALL SDL_CreateRGBSurfaceFrom
        (void *pixels, int width, int height, int depth, int pitch,
        Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);

SDL_FreeSurface
    void SDLCALL SDL_FreeSurface(SDL_Surface *surface);

SDL_ConvertSurface
    SDL_Surface * SDLCALL SDL_ConvertSurface
        (SDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags);

SDL_LockSurface
    int SDLCALL SDL_LockSurface(SDL_Surface *surface);

SDL_UnlockSurface
    void SDLCALL SDL_UnlockSurface(SDL_Surface *surface);
*/

static vPtr (*_SDL_CreateRGBSurface)(uint32_t flags, int width, int height, int depth,
                                     uint32_t Rmask, uint32_t Gmask, uint32_t Bmask, uint32_t Amask) = 0;
DFhackCExport vPtr SDL_CreateRGBSurface(uint32_t flags, int width, int height, int depth,
                                     uint32_t Rmask, uint32_t Gmask, uint32_t Bmask, uint32_t Amask)
{
    return _SDL_CreateRGBSurface(flags, width, height, depth, Rmask, Gmask, Bmask, Amask);
}

static vPtr (*_SDL_CreateRGBSurfaceFrom)(vPtr pixels, int width, int height, int depth, int pitch,
                                         uint32_t Rmask, uint32_t Gmask, uint32_t Bmask, uint32_t Amask) = 0;
DFhackCExport vPtr SDL_CreateRGBSurfaceFrom(vPtr pixels, int width, int height, int depth, int pitch,
                                         uint32_t Rmask, uint32_t Gmask, uint32_t Bmask, uint32_t Amask)
{
    return _SDL_CreateRGBSurfaceFrom(pixels, width, height, depth, pitch, Rmask, Gmask, Bmask, Amask);
}

static void (*_SDL_FreeSurface)(vPtr surface) = 0;
DFhackCExport void SDL_FreeSurface(vPtr surface)
{
    _SDL_FreeSurface(surface);
}

static vPtr (*_SDL_ConvertSurface)(vPtr surface, vPtr format, uint32_t flags) = 0;
DFhackCExport vPtr SDL_ConvertSurface(vPtr surface, vPtr format, uint32_t flags)
{
    return _SDL_ConvertSurface(surface, format, flags);
}

static int (*_SDL_LockSurface)(vPtr surface) = 0;
DFhackCExport int SDL_LockSurface(vPtr surface)
{
    return _SDL_LockSurface(surface);
}

static void (*_SDL_UnlockSurface)(vPtr surface) = 0;
DFhackCExport void SDL_UnlockSurface(vPtr surface)
{
    _SDL_UnlockSurface(surface);
}

/***** More surface stuff
SDL_MapRGB
     Uint32 SDLCALL SDL_MapRGB
        (const SDL_PixelFormat * const format, const Uint8 r, const Uint8 g, const Uint8 b);

SDL_SaveBMP_RW
    int SDLCALL SDL_SaveBMP_RW
        (SDL_Surface *surface, SDL_RWops *dst, int freedst);

SDL_SetAlpha
    int SDLCALL SDL_SetAlpha(SDL_Surface *surface, Uint32 flag, Uint8 alpha);
    
SDL_SetColorKey
    int SDLCALL SDL_SetColorKey(SDL_Surface *surface, Uint32 flag, Uint32 key);

SDL_GetVideoInfo
    const SDL_VideoInfo * SDLCALL SDL_GetVideoInfo(void);

SDL_SetVideoMode
    SDL_Surface * SDLCALL SDL_SetVideoMode
        (int width, int height, int bpp, Uint32 flags);

SDL_UpperBlit
    int SDLCALL SDL_UpperBlit
        (SDL_Surface *src, SDL_Rect *srcrect, SDL_Surface *dst, SDL_Rect *dstrect);
*/

static uint32_t (*_SDL_MapRGB)(vPtr pixelformat, uint8_t r, uint8_t g, uint8_t b) = 0;
DFhackCExport uint32_t SDL_MapRGB(vPtr pixelformat, uint8_t r, uint8_t g, uint8_t b)
{
    return _SDL_MapRGB(pixelformat,r,g,b);
}

static int (*_SDL_SaveBMP_RW)(vPtr surface, vPtr dst, int freedst) = 0;
DFhackCExport int SDL_SaveBMP_RW(vPtr surface, vPtr dst, int freedst)
{
    return _SDL_SaveBMP_RW(surface,dst,freedst);
}

static int (*_SDL_SetAlpha)(vPtr surface, uint32_t flag, uint8_t alpha) = 0;
DFhackCExport int SDL_SetAlpha(vPtr surface, uint32_t flag, uint8_t alpha)
{
    return _SDL_SetAlpha(surface,flag,alpha);
}

static int (*_SDL_SetColorKey)(vPtr surface, uint32_t flag, uint32_t key) = 0;
DFhackCExport int SDL_SetColorKey(vPtr surface, uint32_t flag, uint32_t key)
{
    return _SDL_SetColorKey(surface,flag,key);
}

static vPtr (*_SDL_GetVideoInfo)(void) = 0;
DFhackCExport vPtr SDL_GetVideoInfo(void)
{
    return _SDL_GetVideoInfo();
}

static vPtr (*_SDL_SetVideoMode)(int width, int height, int bpp, uint32_t flags) = 0;
DFhackCExport vPtr SDL_SetVideoMode(int width, int height, int bpp, uint32_t flags)
{
    return _SDL_SetVideoMode(width, height, bpp, flags);
}

static int (*_SDL_UpperBlit)(DFHack::DFSDL_Surface* src, DFHack::DFSDL_Rect* srcrect, DFHack::DFSDL_Surface* dst, DFHack::DFSDL_Rect* dstrect) = 0;
DFhackCExport int SDL_UpperBlit(DFHack::DFSDL_Surface* src, DFHack::DFSDL_Rect* srcrect, DFHack::DFSDL_Surface* dst, DFHack::DFSDL_Rect* dstrect)
{
    if ( dstrect != NULL && dstrect->h != 0 && dstrect->w != 0 )
    {
        DFHack::Core & c = DFHack::Core::getInstance();
        DFHack::Graphic* g = c.getGraphic();
        DFHack::DFTileSurface* ov = g->Call(dstrect->x/dstrect->w, dstrect->y/dstrect->h);

        if ( ov != NULL )
        {
            if ( ov->paintOver )
            {
                _SDL_UpperBlit(src, srcrect, dst, dstrect);
            }

            DFHack::DFSDL_Rect* dstrect2 = new DFHack::DFSDL_Rect;
            dstrect2->x = dstrect->x;
            dstrect2->y = dstrect->y;
            dstrect2->w = dstrect->w;
            dstrect2->h = dstrect->h;

            if ( ov->dstResize != NULL )
            {
                DFHack::DFSDL_Rect* r = (DFHack::DFSDL_Rect*)ov->dstResize;
                dstrect2->x += r->x;
                dstrect2->y += r->y;
                dstrect2->w += r->w;
                dstrect2->h += r->h;
            }

            int result = _SDL_UpperBlit(ov->surface, ov->rect, dst, dstrect2);
            delete dstrect2;
            return result;
        }
    }

    return _SDL_UpperBlit(src, srcrect, dst, dstrect);
}

/***** Even more surface
SDL_GL_GetAttribute
    int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int* value);
    
SDL_GL_SetAttribute
    int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);
    
SDL_WM_SetCaption
    void SDLCALL SDL_WM_SetCaption(const char *title, const char *icon);
    
SDL_WM_SetIcon
    void SDLCALL SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);
    
SDL_FillRect
    int SDLCALL SDL_FillRect(SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);
*/


static void * (*_SDL_GetVideoSurface)( void ) = 0;
DFhackCExport void * SDL_GetVideoSurface(void)
{
    return _SDL_GetVideoSurface();
}

static void * (*_SDL_DisplayFormat)( void * surface ) = 0;
DFhackCExport void * SDL_DisplayFormat(void *surface)
{
    return _SDL_DisplayFormat(surface);
}

// SDL_Surface *SDL_DisplayFormatAlpha(SDL_Surface *surface);
static void * (*_SDL_DisplayFormatAlpha)( void * surface ) = 0;
DFhackCExport void * SDL_DisplayFormatAlpha(void *surface)
{
    return _SDL_DisplayFormatAlpha(surface);
}

//void SDL_GetRGBA(Uint32 pixel, SDL_PixelFormat *fmt, Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);

static void (*_SDL_GetRGBA)(uint32_t pixel, void * fmt, uint8_t * r, uint8_t * g, uint8_t * b, uint8_t *a) = 0;
DFhackCExport void SDL_GetRGBA(uint32_t pixel, void * fmt, uint8_t * r, uint8_t * g, uint8_t * b, uint8_t *a)
{
    return _SDL_GetRGBA(pixel, fmt, r, g, b, a);
}

static int (*_SDL_GL_GetAttribute)(int attr, int * value) = 0;
DFhackCExport int SDL_GL_GetAttribute(int attr, int * value)
{
    return _SDL_GL_GetAttribute(attr,value);
}

static int (*_SDL_GL_SetAttribute)(int attr, int value) = 0;
DFhackCExport int SDL_GL_SetAttribute(int attr, int value)
{
    return _SDL_GL_SetAttribute(attr,value);
}

static void (*_SDL_WM_SetCaption)(const char *title, const char *icon) = 0;
DFhackCExport void SDL_WM_SetCaption(const char *title, const char *icon)
{
    //_SDL_WM_SetCaption("DwarfHacked the Fortress of Hacks",icon);
    _SDL_WM_SetCaption(title,icon);
}

static void (*_SDL_WM_SetIcon)(vPtr icon, uint8_t *mask) = 0;
DFhackCExport void SDL_WM_SetIcon(vPtr icon, uint8_t *mask)
{
    _SDL_WM_SetIcon(icon, mask);
}

static int (*_SDL_FillRect)(vPtr dst, vPtr dstrect, uint32_t color) = 0;
DFhackCExport int SDL_FillRect(vPtr dst, vPtr dstrect, uint32_t color)
{
    return _SDL_FillRect(dst,dstrect,color);
}

/***** Events and input
SDL_EnableKeyRepeat
    int SDLCALL SDL_EnableKeyRepeat(int delay, int interval);
SDL_EnableUNICODE
    int SDLCALL SDL_EnableUNICODE(int enable);
SDL_GetKeyState
    Uint8 * SDLCALL SDL_GetKeyState(int *numkeys);
SDL_PollEvent
    int SDLCALL SDL_PollEvent(SDL_Event *event);
*/

static int (*_SDL_EnableKeyRepeat)(int delay, int interval) = 0;
DFhackCExport int SDL_EnableKeyRepeat(int delay, int interval)
{
    return _SDL_EnableKeyRepeat(delay, interval);
}

static int (*_SDL_EnableUNICODE)(int enable) = 0;
DFhackCExport int SDL_EnableUNICODE(int enable)
{
    if(!enable)
    {
        fprintf(stderr, "SDL_EnableUNICODE turned off.  Keybindings may break.\n");
    }
    return _SDL_EnableUNICODE(enable);
}

static uint8_t * (*_SDL_GetKeyState)(int* numkeys) = 0;
DFhackCExport uint8_t * SDL_GetKeyState(int* numkeys)
{
    return _SDL_GetKeyState(numkeys);
}

// called by DF to check input events
static int (*_SDL_PollEvent)(SDL::Event* event) = 0;
DFhackCExport int SDL_PollEvent(SDL::Event* event)
{
    pollevent_again:
    // if SDL returns 0 here, it means there are no more events. return 0
    int orig_return = _SDL_PollEvent(event);
    if(!orig_return)
        return 0;
    // otherwise we have an event to filter
    else if( event != 0 )
    {
        DFHack::Core & c = DFHack::Core::getInstance();
        // if we consume the event, ask SDL for more.
        if(!c.DFH_SDL_Event(event))
            goto pollevent_again;
    }
    return orig_return;
}

/***** error handling
SDL_GetError
    char * SDLCALL SDL_GetError(void);
SDL_SetError
    extern DECLSPEC void SDLCALL SDL_SetError(const char *fmt, ...);
SDL_ClearError
    extern DECLSPEC void SDLCALL SDL_ClearError(void);
SDL_Error
    extern DECLSPEC void SDLCALL SDL_Error(SDL_errorcode code);
*/

static char * (*_SDL_GetError)(void) = 0;
DFhackCExport char * SDL_GetError(void)
{
    return _SDL_GetError();
}

static void (*_SDL_SetError)(const char *fmt, ...) = 0;
DFhackCExport void SDL_SetError(const char *fmt, ...)
{
    char buf[1024];
    va_list args;
    va_start(args,fmt);
    vsnprintf(buf, sizeof(buf) - 1 ,fmt,args);
    va_end(args);
    _SDL_SetError(buf);
}

static void (*_SDL_ClearError)(void) = 0;
DFhackCExport void SDL_ClearError(void)
{
    _SDL_ClearError();
}

static void (*_SDL_Error)(int code) = 0;
DFhackCExport void SDL_Error(int code)
{
    _SDL_Error(code);
}

/***** symbol resolution
SDL_LoadFunction
    extern DECLSPEC void * SDLCALL SDL_LoadFunction(void *handle, const char *name);
SDL_LoadObject
    extern DECLSPEC void * SDLCALL SDL_LoadObject(const char *sofile);
SDL_UnloadObject
    extern DECLSPEC void SDLCALL SDL_UnloadObject(void *handle);
*/

static void * (*_SDL_LoadFunction)(vPtr handle, const char *name) = 0;
DFhackCExport void * SDL_LoadFunction(vPtr handle, const char *name)
{
    return _SDL_LoadFunction(handle, name);
}

extern "C" static vPtr (*_SDL_LoadObject)(const char *sofile) = 0;
DFhackCExport vPtr SDL_LoadObject(const char *sofile)
{
    return _SDL_LoadObject(sofile);
}

static void (*_SDL_UnloadObject)(vPtr handle) = 0;
DFhackCExport void SDL_UnloadObject(vPtr handle)
{
    _SDL_UnloadObject(handle);
}

/***** r/w
SDL_ReadBE32
    extern DECLSPEC Uint32 SDLCALL SDL_ReadBE32(SDL_RWops *src);
SDL_ReadLE16
    extern DECLSPEC Uint16 SDLCALL SDL_ReadLE16(SDL_RWops *src);
SDL_ReadLE32
    extern DECLSPEC Uint32 SDLCALL SDL_ReadLE32(SDL_RWops *src);
*/

static uint32_t (*_SDL_ReadBE32)(vPtr src) = 0;
DFhackCExport uint32_t SDL_ReadBE32(vPtr src)
{
    return _SDL_ReadBE32(src);
}

static uint16_t (*_SDL_ReadLE16)(vPtr src) = 0;
DFhackCExport uint16_t SDL_ReadLE16(vPtr src)
{
    return _SDL_ReadLE16(src);
}

static uint32_t (*_SDL_ReadLE32)(vPtr src) = 0;
DFhackCExport uint32_t SDL_ReadLE32(vPtr src)
{
    return _SDL_ReadLE32(src);
}

/***** Misc
SDL_RWFromFile
    SDL_RWops * SDLCALL SDL_RWFromFile(const char *file, const char *mode);
SDL_SetModuleHandle
    void SDLCALL SDL_SetModuleHandle(void *hInst);
SDL_ShowCursor
    int SDLCALL SDL_ShowCursor(int toggle);
SDL_strlcpy
    size_t SDLCALL SDL_strlcpy(char *dst, const char *src, size_t maxlen);
*/

static vPtr (*_SDL_RWFromFile)(const char* file, const char *mode) = 0;
DFhackCExport vPtr SDL_RWFromFile(const char* file, const char *mode)
{
    return _SDL_RWFromFile(file, mode);
}

static void (*_SDL_SetModuleHandle)(vPtr hInst) = 0;
DFhackCExport void SDL_SetModuleHandle(vPtr hInst)
{
    _SDL_SetModuleHandle(hInst);
}

static int (*_SDL_ShowCursor)(int toggle) = 0;
DFhackCExport int SDL_ShowCursor(int toggle)
{
    return _SDL_ShowCursor(toggle);
}

static size_t (*_SDL_strlcpy)(char *dst, const char *src, size_t maxlen) = 0;
DFhackCExport size_t SDL_strlcpy(char *dst, const char *src, size_t maxlen)
{
    if(!_SDL_strlcpy)
    {
        HMODULE realSDLlib =  LoadLibrary("SDLreal.dll");
        if(!realSDLlib)
        {
            exit(-111);
        }
        _SDL_strlcpy = (size_t (*)(char*, const char*, size_t))GetProcAddress(realSDLlib,"SDL_strlcpy");
    }
    return _SDL_strlcpy(dst,src,maxlen);
}

/***** The real meat of this
SDL_Init
SDL_Quit
SDL_GL_SwapBuffers
    void SDLCALL SDL_GL_SwapBuffers(void);
*/


// hook - called at program exit
static void (*_SDL_Quit)(void) = 0;
DFhackCExport void SDL_Quit(void)
{
    DFHack::Core & c = DFHack::Core::getInstance();
    c.Shutdown();
    if(_SDL_Quit)
    {
        _SDL_Quit();
    }
}
// this is supported from 0.31.04 forward
DFhackCExport int SDL_NumJoysticks(void)
{
    DFHack::Core & c = DFHack::Core::getInstance();
    return c.Update();
}

static void (*_SDL_GL_SwapBuffers)(void) = 0;
DFhackCExport void SDL_GL_SwapBuffers(void)
{
    if(!inited)
        FirstCall();
    _SDL_GL_SwapBuffers();
}

// hook - called every tick in the 2D mode of DF
static int (*_SDL_Flip)(void * some_ptr) = 0;
DFhackCExport int SDL_Flip(void * some_ptr)
{
    if(!inited)
        FirstCall();
    return _SDL_Flip(some_ptr);
}

static int (*_SDL_Init)(uint32_t flags) = 0;
DFhackCExport int SDL_Init(uint32_t flags)
{
    if(!inited)
        FirstCall();
    return _SDL_Init(flags);
}

/*
MORE CRAP
*/
static void * (*_SDL_CreateSemaphore)(uint32_t initial_value) = 0;
DFhackCExport void *SDL_CreateSemaphore(uint32_t initial_value)
{
    if(!inited)
        FirstCall();
    return _SDL_CreateSemaphore(initial_value);
}

static vPtr (*_SDL_CreateThread)(int (*fn)(void *), void *data) = 0;
DFhackCExport  vPtr SDL_CreateThread(int (*fn)(void *), void *data)
{
    if(!inited)
        FirstCall();
    return _SDL_CreateThread(fn,data);
}


static void (*_SDL_Delay)(uint32_t ms) = 0;
DFhackCExport void SDL_Delay(uint32_t ms)
{
    if(!inited)
        FirstCall();
    _SDL_Delay(ms);
}

static void (*_SDL_DestroySemaphore)(void *sem) = 0;
DFhackCExport void SDL_DestroySemaphore(void *sem)
{
    if(!inited)
        FirstCall();
    _SDL_DestroySemaphore(sem);
}

static uint8_t (*_SDL_GetAppState)(void) = 0;
DFhackCExport uint8_t SDL_GetAppState(void)
{
    if(!inited)
        FirstCall();
    return _SDL_GetAppState();
}

static uint8_t (*_SDL_GetMouseState)(int *, int *) = 0;
DFhackCExport uint8_t SDL_GetMouseState(int *x, int *y)
{
    if(!inited)
        FirstCall();
    return _SDL_GetMouseState(x,y);
}

static int (*_SDL_InitSubSystem)(uint32_t flags) = 0;
DFhackCExport int SDL_InitSubSystem(uint32_t flags)
{
    if(!inited)
        FirstCall();
    return _SDL_InitSubSystem(flags);
}

static int (*_SDL_SemPost)(void *sem) = 0;
DFhackCExport int SDL_SemPost(void *sem)
{
    if(!inited)
        FirstCall();
    return _SDL_SemPost(sem);
}

static int (*_SDL_SemTryWait)(void *sem) = 0;
DFhackCExport int SDL_SemTryWait(void *sem)
{
    if(!inited)
        FirstCall();
    return _SDL_SemTryWait(sem);
}

static int (*_SDL_SemWait)(void *sem) = 0;
DFhackCExport int SDL_SemWait(void *sem)
{
    if(!inited)
        FirstCall();
    return _SDL_SemWait(sem);
}

static uint32_t (*_SDL_ThreadID)(void) = 0;
DFhackCExport uint32_t SDL_ThreadID(void)
{
    if(!inited)
        FirstCall();
    return _SDL_ThreadID();
}

// FIXME: this has to be thread-safe.
bool FirstCall()
{
    // reroute stdout and stderr
    freopen("stdout.log", "w", stdout);
    freopen("stderr.log", "w", stderr);
    HMODULE realSDLlib =  LoadLibrary("SDLreal.dll");
    if(!realSDLlib)
    {
        MessageBox(0,"Can't load SDLreal.dll\n","Error", MB_OK);
        fprintf(stderr, "Can't load SDLreal.dll\n");
        return 0;
    }
    fprintf(stderr, "FirstCall()\n");
    // stuff for DF
    _SDL_AddTimer = (void*(*)(uint32_t, void*, void*)) GetProcAddress(realSDLlib,"SDL_AddTimer");
    _SDL_CondSignal = (int (*)(vPtr))GetProcAddress(realSDLlib,"SDL_CondSignal");
    _SDL_CondWait = (int (*)(vPtr, vPtr))GetProcAddress(realSDLlib,"SDL_CondWait");
    _SDL_ConvertSurface = (void*(*)(void*, void*, uint32_t))GetProcAddress(realSDLlib,"SDL_ConvertSurface");
    _SDL_CreateCond = (vPtr(*)())GetProcAddress(realSDLlib,"SDL_CreateCond");
    _SDL_CreateMutex = (vPtr(*)())GetProcAddress(realSDLlib,"SDL_CreateMutex");
    _SDL_CreateRGBSurface = (void*(*)(uint32_t, int, int, int, uint32_t, uint32_t, uint32_t, uint32_t))GetProcAddress(realSDLlib,"SDL_CreateRGBSurface");
    _SDL_CreateRGBSurfaceFrom = (void*(*)(void*, int, int, int, int, uint32_t, uint32_t, uint32_t, uint32_t))GetProcAddress(realSDLlib,"SDL_CreateRGBSurfaceFrom");
    _SDL_DestroyCond = (void (*)(vPtr))GetProcAddress(realSDLlib,"SDL_DestroyCond");
    _SDL_DestroyMutex = (void (*)(vPtr))GetProcAddress(realSDLlib,"SDL_DestroyMutex");
    _SDL_EnableKeyRepeat = (int (*)(int, int))GetProcAddress(realSDLlib,"SDL_EnableKeyRepeat");
    _SDL_EnableUNICODE = (int (*)(int))GetProcAddress(realSDLlib,"SDL_EnableUNICODE");
    _SDL_GetVideoSurface = (void*(*)())GetProcAddress(realSDLlib,"SDL_GetVideoSurface");
    _SDL_DisplayFormat = (void * (*) (void *))GetProcAddress(realSDLlib,"SDL_DisplayFormat");
    _SDL_DisplayFormatAlpha = (void * (*) (void *))GetProcAddress(realSDLlib,"SDL_DisplayFormatAlpha");
    _SDL_GetRGBA = (void (*) (uint32_t, void *, uint8_t *, uint8_t *, uint8_t *, uint8_t *))GetProcAddress(realSDLlib,"SDL_GetRGBA");
    _SDL_FreeSurface = (void (*)(void*))GetProcAddress(realSDLlib,"SDL_FreeSurface");
    _SDL_GL_GetAttribute = (int (*)(int, int*))GetProcAddress(realSDLlib,"SDL_GL_GetAttribute");
    _SDL_GL_SetAttribute = (int (*)(int, int))GetProcAddress(realSDLlib,"SDL_GL_SetAttribute");
    _SDL_GL_SwapBuffers = (void (*)())GetProcAddress(realSDLlib,"SDL_GL_SwapBuffers");
    _SDL_GetError = (char*(*)())GetProcAddress(realSDLlib,"SDL_GetError");
    _SDL_GetKeyState = (uint8_t*(*)(int*))GetProcAddress(realSDLlib,"SDL_GetKeyState");
    _SDL_GetTicks = (uint32_t (*)())GetProcAddress(realSDLlib,"SDL_GetTicks");
    _SDL_GetVideoInfo = (void*(*)())GetProcAddress(realSDLlib,"SDL_GetVideoInfo");
    _SDL_Init = (int (*)(uint32_t))GetProcAddress(realSDLlib,"SDL_Init");
    _SDL_Flip = (int (*)( void * )) GetProcAddress(realSDLlib, "SDL_Flip");
    _SDL_LockSurface = (int (*)(void*))GetProcAddress(realSDLlib,"SDL_LockSurface");
    _SDL_MapRGB = (uint32_t (*)(void*, uint8_t, uint8_t, uint8_t))GetProcAddress(realSDLlib,"SDL_MapRGB");
    _SDL_PollEvent = (int (*)(SDL::Event*))GetProcAddress(realSDLlib,"SDL_PollEvent");
    _SDL_Quit = (void (*)())GetProcAddress(realSDLlib,"SDL_Quit");
    _SDL_RWFromFile = (void*(*)(const char*, const char*))GetProcAddress(realSDLlib,"SDL_RWFromFile");
    _SDL_RemoveTimer = (bool (*)(void*))GetProcAddress(realSDLlib,"SDL_RemoveTimer");
    _SDL_SaveBMP_RW = (int (*)(void*, void*, int))GetProcAddress(realSDLlib,"SDL_SaveBMP_RW");
    _SDL_SetAlpha = (int (*)(void*, uint32_t, uint8_t))GetProcAddress(realSDLlib,"SDL_SetAlpha");
    _SDL_SetColorKey = (int (*)(void*, uint32_t, uint32_t))GetProcAddress(realSDLlib,"SDL_SetColorKey");
    _SDL_SetModuleHandle = (void (*)(void*))GetProcAddress(realSDLlib,"SDL_SetModuleHandle");
    _SDL_SetVideoMode = (void*(*)(int, int, int, uint32_t))GetProcAddress(realSDLlib,"SDL_SetVideoMode");
    _SDL_ShowCursor = (int (*)(int))GetProcAddress(realSDLlib,"SDL_ShowCursor");
    _SDL_UnlockSurface = (void (*)(void*))GetProcAddress(realSDLlib,"SDL_UnlockSurface");
    _SDL_UpperBlit = (int (*)(DFHack::DFSDL_Surface*, DFHack::DFSDL_Rect*, DFHack::DFSDL_Surface*, DFHack::DFSDL_Rect*))GetProcAddress(realSDLlib,"SDL_UpperBlit");
    _SDL_WM_SetCaption = (void (*)(const char*, const char*))GetProcAddress(realSDLlib,"SDL_WM_SetCaption");
    _SDL_WM_SetIcon = (void (*)(void*, uint8_t*))GetProcAddress(realSDLlib,"SDL_WM_SetIcon");
    _SDL_mutexP = (int (*)(vPtr))GetProcAddress(realSDLlib,"SDL_mutexP");
    _SDL_mutexV = (int (*)(vPtr))GetProcAddress(realSDLlib,"SDL_mutexV");
    _SDL_strlcpy = (size_t (*)(char*, const char*, size_t))GetProcAddress(realSDLlib,"SDL_strlcpy");
    
    // stuff for SDL_Image
    _SDL_ClearError = (void (*)())GetProcAddress(realSDLlib,"SDL_ClearError");
    _SDL_Error = (void (*)(int))GetProcAddress(realSDLlib,"SDL_Error");
    _SDL_LoadFunction = (void*(*)(vPtr, const char*))GetProcAddress(realSDLlib,"SDL_LoadFunction");
    _SDL_LoadObject = (vPtr(*)(const char*))GetProcAddress(realSDLlib,"SDL_LoadObject");
    _SDL_ReadBE32 = (uint32_t (*)(void*))GetProcAddress(realSDLlib,"SDL_ReadBE32");
    _SDL_ReadLE16 = (uint16_t (*)(void*))GetProcAddress(realSDLlib,"SDL_ReadLE16");
    _SDL_ReadLE32 = (uint32_t (*)(void*))GetProcAddress(realSDLlib,"SDL_ReadLE32");
    _SDL_SetError = (void (*)(const char*, ...))GetProcAddress(realSDLlib,"SDL_SetError");
    _SDL_UnloadObject = (void (*)(vPtr))GetProcAddress(realSDLlib,"SDL_UnloadObject");
    _SDL_FillRect = (int (*)(void*,void*,uint32_t))GetProcAddress(realSDLlib,"SDL_FillRect");
    
    // new in DF 0.31.04
    _SDL_CreateSemaphore = (void* (*)(uint32_t))GetProcAddress(realSDLlib,"SDL_CreateSemaphore");
    _SDL_CreateThread = (vPtr (*)(int (*fn)(void *), void *data))GetProcAddress(realSDLlib,"SDL_CreateThread");
    _SDL_Delay = (void (*)(uint32_t))GetProcAddress(realSDLlib,"SDL_Delay");
    _SDL_DestroySemaphore = (void (*)(void *))GetProcAddress(realSDLlib,"SDL_DestroySemaphore");
    _SDL_GetAppState = (uint8_t (*)(void))GetProcAddress(realSDLlib,"SDL_GetAppState");
    _SDL_GetMouseState = (uint8_t (*)(int *, int *))GetProcAddress(realSDLlib,"SDL_GetMouseState");
    _SDL_InitSubSystem = (int (*)(uint32_t))GetProcAddress(realSDLlib,"SDL_InitSubSystem");
    _SDL_SemPost = (int (*)(void *))GetProcAddress(realSDLlib,"SDL_SemPost");
    _SDL_SemTryWait = (int (*)(void *))GetProcAddress(realSDLlib,"SDL_SemTryWait");
    _SDL_SemWait = (int (*)(void *))GetProcAddress(realSDLlib,"SDL_SemWait");
    _SDL_ThreadID = (uint32_t (*)(void))GetProcAddress(realSDLlib,"SDL_ThreadID");
    
    _SDL_EnableUNICODE(1);

    fprintf(stderr,"Initized HOOKS!\n");
    inited = true;
    return 1;
}