src/joystick/windows/SDL_mmjoystick.c - third_party/sdl - Git at Google

 /*
   Simple DirectMedia Layer
   Copyright (C) 1997-2021 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"

 #ifdef SDL_JOYSTICK_WINMM

 /* Win32 MultiMedia Joystick driver, contributed by Andrei de A. Formiga */

 #include "../../core/windows/SDL_windows.h"
 #include <mmsystem.h>
 #include <regstr.h>

 #include "SDL_events.h"
 #include "SDL_joystick.h"
 #include "../SDL_sysjoystick.h"
 #include "../SDL_joystick_c.h"

 #ifdef REGSTR_VAL_JOYOEMNAME
 #undef REGSTR_VAL_JOYOEMNAME
 #endif
 #define REGSTR_VAL_JOYOEMNAME "OEMName"

 #define MAX_JOYSTICKS   16
 #define MAX_AXES    6       /* each joystick can have up to 6 axes */
 #define MAX_BUTTONS 32      /* and 32 buttons                      */
 #define JOY_BUTTON_FLAG(n)  (1<<n)


 /* array to hold joystick ID values */
 static UINT SYS_JoystickID[MAX_JOYSTICKS];
 static JOYCAPSA SYS_Joystick[MAX_JOYSTICKS];
 static char *SYS_JoystickName[MAX_JOYSTICKS];

 /* The private structure used to keep track of a joystick */
 struct joystick_hwdata
 {
     /* joystick ID */
     UINT id;

     /* values used to translate device-specific coordinates into
        SDL-standard ranges */
     struct _transaxis
     {
         int offset;
         float scale;
     } transaxis[6];
 };

 /* Convert a Windows Multimedia API return code to a text message */
 static void SetMMerror(char *function, int code);


 static char *
 GetJoystickName(int index, const char *szRegKey)
 {
     /* added 7/24/2004 by Eckhard Stolberg */
     /*
        see if there is a joystick for the current
        index (1-16) listed in the registry
      */
     char *name = NULL;
     HKEY hTopKey;
     HKEY hKey;
     DWORD regsize;
     LONG regresult;
     char regkey[256];
     char regvalue[256];
     char regname[256];

     SDL_snprintf(regkey, SDL_arraysize(regkey),
 #ifdef UNICODE
                  "%S\\%s\\%S",
 #else
                  "%s\\%s\\%s",
 #endif
                  REGSTR_PATH_JOYCONFIG, szRegKey, REGSTR_KEY_JOYCURR);
     hTopKey = HKEY_LOCAL_MACHINE;
     regresult = RegOpenKeyExA(hTopKey, regkey, 0, KEY_READ, &hKey);
     if (regresult != ERROR_SUCCESS) {
         hTopKey = HKEY_CURRENT_USER;
         regresult = RegOpenKeyExA(hTopKey, regkey, 0, KEY_READ, &hKey);
     }
     if (regresult != ERROR_SUCCESS) {
         return NULL;
     }

     /* find the registry key name for the joystick's properties */
     regsize = sizeof(regname);
     SDL_snprintf(regvalue, SDL_arraysize(regvalue), "Joystick%d%s", index + 1,
                  REGSTR_VAL_JOYOEMNAME);
     regresult =
         RegQueryValueExA(hKey, regvalue, 0, 0, (LPBYTE) regname, &regsize);
     RegCloseKey(hKey);

     if (regresult != ERROR_SUCCESS) {
         return NULL;
     }

     /* open that registry key */
     SDL_snprintf(regkey, SDL_arraysize(regkey),
 #ifdef UNICODE
                  "%S\\%s",
 #else
                  "%s\\%s",
 #endif
                  REGSTR_PATH_JOYOEM, regname);
     regresult = RegOpenKeyExA(hTopKey, regkey, 0, KEY_READ, &hKey);
     if (regresult != ERROR_SUCCESS) {
         return NULL;
     }

     /* find the size for the OEM name text */
     regsize = sizeof(regvalue);
     regresult =
         RegQueryValueExA(hKey, REGSTR_VAL_JOYOEMNAME, 0, 0, NULL, &regsize);
     if (regresult == ERROR_SUCCESS) {
         /* allocate enough memory for the OEM name text ... */
         name = (char *) SDL_malloc(regsize);
         if (name) {
             /* ... and read it from the registry */
             regresult = RegQueryValueExA(hKey,
                                          REGSTR_VAL_JOYOEMNAME, 0, 0,
                                          (LPBYTE) name, &regsize);
         }
     }
     RegCloseKey(hKey);

     return (name);
 }

 static int numjoysticks = 0;

 /* Function to scan the system for joysticks.
  * Joystick 0 should be the system default joystick.
  * It should return 0, or -1 on an unrecoverable fatal error.
  */
 static int
 WINMM_JoystickInit(void)
 {
     int i;
     int maxdevs;
     JOYINFOEX joyinfo;
     JOYCAPSA joycaps;
     MMRESULT result;

     /* Reset the joystick ID & name mapping tables */
     for (i = 0; i < MAX_JOYSTICKS; ++i) {
         SYS_JoystickID[i] = 0;
         SYS_JoystickName[i] = NULL;
     }

     /* Loop over all potential joystick devices */
     numjoysticks = 0;
     maxdevs = joyGetNumDevs();
     for (i = JOYSTICKID1; i < maxdevs && numjoysticks < MAX_JOYSTICKS; ++i) {

         joyinfo.dwSize = sizeof(joyinfo);
         joyinfo.dwFlags = JOY_RETURNALL;
         result = joyGetPosEx(i, &joyinfo);
         if (result == JOYERR_NOERROR) {
             result = joyGetDevCapsA(i, &joycaps, sizeof(joycaps));
             if (result == JOYERR_NOERROR) {
                 SYS_JoystickID[numjoysticks] = i;
                 SYS_Joystick[numjoysticks] = joycaps;
                 SYS_JoystickName[numjoysticks] =
                     GetJoystickName(i, joycaps.szRegKey);
                 numjoysticks++;
             }
         }
     }
     return numjoysticks;
 }

 static int
 WINMM_NumJoysticks(void)
 {
     return numjoysticks;
 }

 static void
 WINMM_JoystickDetect(void)
 {
 }

 /* Function to get the device-dependent name of a joystick */
 static const char *
 WINMM_JoystickGetDeviceName(int device_index)
 {
     if (SYS_JoystickName[device_index] != NULL) {
         return (SYS_JoystickName[device_index]);
     } else {
         return (SYS_Joystick[device_index].szPname);
     }
 }

 static int
 WINMM_JoystickGetDevicePlayerIndex(int device_index)
 {
     return -1;
 }

 static void
 WINMM_JoystickSetDevicePlayerIndex(int device_index, int player_index)
 {
 }

 static SDL_JoystickGUID WINMM_JoystickGetDeviceGUID(int device_index)
 {
     SDL_JoystickGUID guid;
     /* the GUID is just the first 16 chars of the name for now */
     const char *name = WINMM_JoystickGetDeviceName(device_index);
     SDL_zero(guid);
     SDL_memcpy(&guid, name, SDL_min(sizeof(guid), SDL_strlen(name)));
     return guid;
 }

 /* Function to perform the mapping from device index to the instance id for this index */
 static SDL_JoystickID WINMM_JoystickGetDeviceInstanceID(int device_index)
 {
     return device_index;
 }

 /* Function to open a joystick for use.
    The joystick to open is specified by the device index.
    This should fill the nbuttons and naxes fields of the joystick structure.
    It returns 0, or -1 if there is an error.
  */
 static int
 WINMM_JoystickOpen(SDL_Joystick * joystick, int device_index)
 {
     int index, i;
     int caps_flags[MAX_AXES - 2] =
         { JOYCAPS_HASZ, JOYCAPS_HASR, JOYCAPS_HASU, JOYCAPS_HASV };
     int axis_min[MAX_AXES], axis_max[MAX_AXES];

     /* shortcut */
     index = device_index;
     axis_min[0] = SYS_Joystick[index].wXmin;
     axis_max[0] = SYS_Joystick[index].wXmax;
     axis_min[1] = SYS_Joystick[index].wYmin;
     axis_max[1] = SYS_Joystick[index].wYmax;
     axis_min[2] = SYS_Joystick[index].wZmin;
     axis_max[2] = SYS_Joystick[index].wZmax;
     axis_min[3] = SYS_Joystick[index].wRmin;
     axis_max[3] = SYS_Joystick[index].wRmax;
     axis_min[4] = SYS_Joystick[index].wUmin;
     axis_max[4] = SYS_Joystick[index].wUmax;
     axis_min[5] = SYS_Joystick[index].wVmin;
     axis_max[5] = SYS_Joystick[index].wVmax;

     /* allocate memory for system specific hardware data */
     joystick->instance_id = device_index;
     joystick->hwdata =
         (struct joystick_hwdata *) SDL_malloc(sizeof(*joystick->hwdata));
     if (joystick->hwdata == NULL) {
         return SDL_OutOfMemory();
     }
     SDL_memset(joystick->hwdata, 0, sizeof(*joystick->hwdata));

     /* set hardware data */
     joystick->hwdata->id = SYS_JoystickID[index];
     for (i = 0; i < MAX_AXES; ++i) {
         if ((i < 2) || (SYS_Joystick[index].wCaps & caps_flags[i - 2])) {
             joystick->hwdata->transaxis[i].offset = SDL_JOYSTICK_AXIS_MIN - axis_min[i];
             joystick->hwdata->transaxis[i].scale =
                 (float) (SDL_JOYSTICK_AXIS_MAX - SDL_JOYSTICK_AXIS_MIN) / (axis_max[i] - axis_min[i]);
         } else {
             joystick->hwdata->transaxis[i].offset = 0;
             joystick->hwdata->transaxis[i].scale = 1.0; /* Just in case */
         }
     }

     /* fill nbuttons, naxes, and nhats fields */
     joystick->nbuttons = SYS_Joystick[index].wNumButtons;
     joystick->naxes = SYS_Joystick[index].wNumAxes;
     if (SYS_Joystick[index].wCaps & JOYCAPS_HASPOV) {
         joystick->nhats = 1;
     } else {
         joystick->nhats = 0;
     }
     return (0);
 }

 static Uint8
 TranslatePOV(DWORD value)
 {
     Uint8 pos;

     pos = SDL_HAT_CENTERED;
     if (value != JOY_POVCENTERED) {
         if ((value > JOY_POVLEFT) || (value < JOY_POVRIGHT)) {
             pos |= SDL_HAT_UP;
         }
         if ((value > JOY_POVFORWARD) && (value < JOY_POVBACKWARD)) {
             pos |= SDL_HAT_RIGHT;
         }
         if ((value > JOY_POVRIGHT) && (value < JOY_POVLEFT)) {
             pos |= SDL_HAT_DOWN;
         }
         if (value > JOY_POVBACKWARD) {
             pos |= SDL_HAT_LEFT;
         }
     }
     return (pos);
 }

 static int
 WINMM_JoystickRumble(SDL_Joystick *joystick, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble)
 {
     return SDL_Unsupported();
 }

 static int
 WINMM_JoystickRumbleTriggers(SDL_Joystick *joystick, Uint16 left_rumble, Uint16 right_rumble)
 {
     return SDL_Unsupported();
 }

 static SDL_bool WINMM_JoystickHasLED(SDL_Joystick *joystick)
 {
     return SDL_FALSE;
 }

 static int
 WINMM_JoystickSetLED(SDL_Joystick *joystick, Uint8 red, Uint8 green, Uint8 blue)
 {
     return SDL_Unsupported();
 }

 static int WINMM_JoystickSetSensorsEnabled(SDL_Joystick *joystick, SDL_bool enabled)
 {
     return SDL_Unsupported();
 }

 /* Function to update the state of a joystick - called as a device poll.
  * This function shouldn't update the joystick structure directly,
  * but instead should call SDL_PrivateJoystick*() to deliver events
  * and update joystick device state.
  */
 static void
 WINMM_JoystickUpdate(SDL_Joystick * joystick)
 {
     MMRESULT result;
     int i;
     DWORD flags[MAX_AXES] = { JOY_RETURNX, JOY_RETURNY, JOY_RETURNZ,
                               JOY_RETURNR, JOY_RETURNU, JOY_RETURNV
     };
     DWORD pos[MAX_AXES];
     struct _transaxis *transaxis;
     int value;
     JOYINFOEX joyinfo;

     joyinfo.dwSize = sizeof(joyinfo);
     joyinfo.dwFlags = JOY_RETURNALL | JOY_RETURNPOVCTS;
     if (!joystick->hats) {
         joyinfo.dwFlags &= ~(JOY_RETURNPOV | JOY_RETURNPOVCTS);
     }
     result = joyGetPosEx(joystick->hwdata->id, &joyinfo);
     if (result != JOYERR_NOERROR) {
         SetMMerror("joyGetPosEx", result);
         return;
     }

     /* joystick motion events */
     pos[0] = joyinfo.dwXpos;
     pos[1] = joyinfo.dwYpos;
     pos[2] = joyinfo.dwZpos;
     pos[3] = joyinfo.dwRpos;
     pos[4] = joyinfo.dwUpos;
     pos[5] = joyinfo.dwVpos;

     transaxis = joystick->hwdata->transaxis;
     for (i = 0; i < joystick->naxes; i++) {
         if (joyinfo.dwFlags & flags[i]) {
             value = (int) (((float) pos[i] + transaxis[i].offset) * transaxis[i].scale);
             SDL_PrivateJoystickAxis(joystick, (Uint8) i, (Sint16) value);
         }
     }

     /* joystick button events */
     if (joyinfo.dwFlags & JOY_RETURNBUTTONS) {
         for (i = 0; i < joystick->nbuttons; ++i) {
             if (joyinfo.dwButtons & JOY_BUTTON_FLAG(i)) {
                 SDL_PrivateJoystickButton(joystick, (Uint8) i, SDL_PRESSED);
             } else {
                 SDL_PrivateJoystickButton(joystick, (Uint8) i, SDL_RELEASED);
             }
         }
     }

     /* joystick hat events */
     if (joyinfo.dwFlags & JOY_RETURNPOV) {
         SDL_PrivateJoystickHat(joystick, 0, TranslatePOV(joyinfo.dwPOV));
     }
 }

 /* Function to close a joystick after use */
 static void
 WINMM_JoystickClose(SDL_Joystick * joystick)
 {
     SDL_free(joystick->hwdata);
 }

 /* Function to perform any system-specific joystick related cleanup */
 static void
 WINMM_JoystickQuit(void)
 {
     int i;
     for (i = 0; i < MAX_JOYSTICKS; i++) {
         SDL_free(SYS_JoystickName[i]);
         SYS_JoystickName[i] = NULL;
     }
 }

 static SDL_bool
 WINMM_JoystickGetGamepadMapping(int device_index, SDL_GamepadMapping *out)
 {
     return SDL_FALSE;
 }


 /* implementation functions */
 void
 SetMMerror(char *function, int code)
 {
     static char *error;
     static char errbuf[1024];

     errbuf[0] = 0;
     switch (code) {
     case MMSYSERR_NODRIVER:
         error = "Joystick driver not present";
         break;

     case MMSYSERR_INVALPARAM:
     case JOYERR_PARMS:
         error = "Invalid parameter(s)";
         break;

     case MMSYSERR_BADDEVICEID:
         error = "Bad device ID";
         break;

     case JOYERR_UNPLUGGED:
         error = "Joystick not attached";
         break;

     case JOYERR_NOCANDO:
         error = "Can't capture joystick input";
         break;

     default:
         SDL_snprintf(errbuf, SDL_arraysize(errbuf),
                      "%s: Unknown Multimedia system error: 0x%x",
                      function, code);
         break;
     }

     if (!errbuf[0]) {
         SDL_snprintf(errbuf, SDL_arraysize(errbuf), "%s: %s", function,
                      error);
     }
     SDL_SetError("%s", errbuf);
 }

 SDL_JoystickDriver SDL_WINMM_JoystickDriver =
 {
     WINMM_JoystickInit,
     WINMM_NumJoysticks,
     WINMM_JoystickDetect,
     WINMM_JoystickGetDeviceName,
     WINMM_JoystickGetDevicePlayerIndex,
     WINMM_JoystickSetDevicePlayerIndex,
     WINMM_JoystickGetDeviceGUID,
     WINMM_JoystickGetDeviceInstanceID,
     WINMM_JoystickOpen,
     WINMM_JoystickRumble,
     WINMM_JoystickRumbleTriggers,
     WINMM_JoystickHasLED,
     WINMM_JoystickSetLED,
     WINMM_JoystickSetSensorsEnabled,
     WINMM_JoystickUpdate,
     WINMM_JoystickClose,
     WINMM_JoystickQuit,
     WINMM_JoystickGetGamepadMapping
 };

 #endif /* SDL_JOYSTICK_WINMM */

 /* vi: set ts=4 sw=4 expandtab: */
	/*
	Simple DirectMedia Layer
	Copyright (C) 1997-2021 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"

	#ifdef SDL_JOYSTICK_WINMM

	/* Win32 MultiMedia Joystick driver, contributed by Andrei de A. Formiga */

	#include "../../core/windows/SDL_windows.h"
	#include <mmsystem.h>
	#include <regstr.h>

	#include "SDL_events.h"
	#include "SDL_joystick.h"
	#include "../SDL_sysjoystick.h"
	#include "../SDL_joystick_c.h"

	#ifdef REGSTR_VAL_JOYOEMNAME
	#undef REGSTR_VAL_JOYOEMNAME
	#endif
	#define REGSTR_VAL_JOYOEMNAME "OEMName"

	#define MAX_JOYSTICKS 16
	#define MAX_AXES 6 /* each joystick can have up to 6 axes */
	#define MAX_BUTTONS 32 /* and 32 buttons */
	#define JOY_BUTTON_FLAG(n) (1<<n)


	/* array to hold joystick ID values */
	static UINT SYS_JoystickID[MAX_JOYSTICKS];
	static JOYCAPSA SYS_Joystick[MAX_JOYSTICKS];
	static char *SYS_JoystickName[MAX_JOYSTICKS];

	/* The private structure used to keep track of a joystick */
	struct joystick_hwdata
	{
	/* joystick ID */
	UINT id;

	/* values used to translate device-specific coordinates into
	SDL-standard ranges */
	struct _transaxis
	{
	int offset;
	float scale;
	} transaxis[6];
	};

	/* Convert a Windows Multimedia API return code to a text message */
	static void SetMMerror(char *function, int code);


	static char *
	GetJoystickName(int index, const char *szRegKey)
	{
	/* added 7/24/2004 by Eckhard Stolberg */
	/*
	see if there is a joystick for the current
	index (1-16) listed in the registry
	*/
	char *name = NULL;
	HKEY hTopKey;
	HKEY hKey;
	DWORD regsize;
	LONG regresult;
	char regkey[256];
	char regvalue[256];
	char regname[256];

	SDL_snprintf(regkey, SDL_arraysize(regkey),
	#ifdef UNICODE
	"%S\\%s\\%S",
	#else
	"%s\\%s\\%s",
	#endif
	REGSTR_PATH_JOYCONFIG, szRegKey, REGSTR_KEY_JOYCURR);
	hTopKey = HKEY_LOCAL_MACHINE;
	regresult = RegOpenKeyExA(hTopKey, regkey, 0, KEY_READ, &hKey);
	if (regresult != ERROR_SUCCESS) {
	hTopKey = HKEY_CURRENT_USER;
	regresult = RegOpenKeyExA(hTopKey, regkey, 0, KEY_READ, &hKey);
	}
	if (regresult != ERROR_SUCCESS) {
	return NULL;
	}

	/* find the registry key name for the joystick's properties */
	regsize = sizeof(regname);
	SDL_snprintf(regvalue, SDL_arraysize(regvalue), "Joystick%d%s", index + 1,
	REGSTR_VAL_JOYOEMNAME);
	regresult =
	RegQueryValueExA(hKey, regvalue, 0, 0, (LPBYTE) regname, &regsize);
	RegCloseKey(hKey);

	if (regresult != ERROR_SUCCESS) {
	return NULL;
	}

	/* open that registry key */
	SDL_snprintf(regkey, SDL_arraysize(regkey),
	#ifdef UNICODE
	"%S\\%s",
	#else
	"%s\\%s",
	#endif
	REGSTR_PATH_JOYOEM, regname);
	regresult = RegOpenKeyExA(hTopKey, regkey, 0, KEY_READ, &hKey);
	if (regresult != ERROR_SUCCESS) {
	return NULL;
	}

	/* find the size for the OEM name text */
	regsize = sizeof(regvalue);
	regresult =
	RegQueryValueExA(hKey, REGSTR_VAL_JOYOEMNAME, 0, 0, NULL, &regsize);
	if (regresult == ERROR_SUCCESS) {
	/* allocate enough memory for the OEM name text ... */
	name = (char *) SDL_malloc(regsize);
	if (name) {
	/* ... and read it from the registry */
	regresult = RegQueryValueExA(hKey,
	REGSTR_VAL_JOYOEMNAME, 0, 0,
	(LPBYTE) name, &regsize);
	}
	}
	RegCloseKey(hKey);

	return (name);
	}

	static int numjoysticks = 0;

	/* Function to scan the system for joysticks.
	* Joystick 0 should be the system default joystick.
	* It should return 0, or -1 on an unrecoverable fatal error.
	*/
	static int
	WINMM_JoystickInit(void)
	{
	int i;
	int maxdevs;
	JOYINFOEX joyinfo;
	JOYCAPSA joycaps;
	MMRESULT result;

	/* Reset the joystick ID & name mapping tables */
	for (i = 0; i < MAX_JOYSTICKS; ++i) {
	SYS_JoystickID[i] = 0;
	SYS_JoystickName[i] = NULL;
	}

	/* Loop over all potential joystick devices */
	numjoysticks = 0;
	maxdevs = joyGetNumDevs();
	for (i = JOYSTICKID1; i < maxdevs && numjoysticks < MAX_JOYSTICKS; ++i) {

	joyinfo.dwSize = sizeof(joyinfo);
	joyinfo.dwFlags = JOY_RETURNALL;
	result = joyGetPosEx(i, &joyinfo);
	if (result == JOYERR_NOERROR) {
	result = joyGetDevCapsA(i, &joycaps, sizeof(joycaps));
	if (result == JOYERR_NOERROR) {
	SYS_JoystickID[numjoysticks] = i;
	SYS_Joystick[numjoysticks] = joycaps;
	SYS_JoystickName[numjoysticks] =
	GetJoystickName(i, joycaps.szRegKey);
	numjoysticks++;
	}
	}
	}
	return numjoysticks;
	}

	static int
	WINMM_NumJoysticks(void)
	{
	return numjoysticks;
	}

	static void
	WINMM_JoystickDetect(void)
	{
	}

	/* Function to get the device-dependent name of a joystick */
	static const char *
	WINMM_JoystickGetDeviceName(int device_index)
	{
	if (SYS_JoystickName[device_index] != NULL) {
	return (SYS_JoystickName[device_index]);
	} else {
	return (SYS_Joystick[device_index].szPname);
	}
	}

	static int
	WINMM_JoystickGetDevicePlayerIndex(int device_index)
	{
	return -1;
	}

	static void
	WINMM_JoystickSetDevicePlayerIndex(int device_index, int player_index)
	{
	}

	static SDL_JoystickGUID WINMM_JoystickGetDeviceGUID(int device_index)
	{
	SDL_JoystickGUID guid;
	/* the GUID is just the first 16 chars of the name for now */
	const char *name = WINMM_JoystickGetDeviceName(device_index);
	SDL_zero(guid);
	SDL_memcpy(&guid, name, SDL_min(sizeof(guid), SDL_strlen(name)));
	return guid;
	}

	/* Function to perform the mapping from device index to the instance id for this index */
	static SDL_JoystickID WINMM_JoystickGetDeviceInstanceID(int device_index)
	{
	return device_index;
	}

	/* Function to open a joystick for use.
	The joystick to open is specified by the device index.
	This should fill the nbuttons and naxes fields of the joystick structure.
	It returns 0, or -1 if there is an error.
	*/
	static int
	WINMM_JoystickOpen(SDL_Joystick * joystick, int device_index)
	{
	int index, i;
	int caps_flags[MAX_AXES - 2] =
	{ JOYCAPS_HASZ, JOYCAPS_HASR, JOYCAPS_HASU, JOYCAPS_HASV };
	int axis_min[MAX_AXES], axis_max[MAX_AXES];

	/* shortcut */
	index = device_index;
	axis_min[0] = SYS_Joystick[index].wXmin;
	axis_max[0] = SYS_Joystick[index].wXmax;
	axis_min[1] = SYS_Joystick[index].wYmin;
	axis_max[1] = SYS_Joystick[index].wYmax;
	axis_min[2] = SYS_Joystick[index].wZmin;
	axis_max[2] = SYS_Joystick[index].wZmax;
	axis_min[3] = SYS_Joystick[index].wRmin;
	axis_max[3] = SYS_Joystick[index].wRmax;
	axis_min[4] = SYS_Joystick[index].wUmin;
	axis_max[4] = SYS_Joystick[index].wUmax;
	axis_min[5] = SYS_Joystick[index].wVmin;
	axis_max[5] = SYS_Joystick[index].wVmax;

	/* allocate memory for system specific hardware data */
	joystick->instance_id = device_index;
	joystick->hwdata =
	(struct joystick_hwdata ) SDL_malloc(sizeof(joystick->hwdata));
	if (joystick->hwdata == NULL) {
	return SDL_OutOfMemory();
	}
	SDL_memset(joystick->hwdata, 0, sizeof(*joystick->hwdata));

	/* set hardware data */
	joystick->hwdata->id = SYS_JoystickID[index];
	for (i = 0; i < MAX_AXES; ++i) {
	if ((i < 2) \|\| (SYS_Joystick[index].wCaps & caps_flags[i - 2])) {
	joystick->hwdata->transaxis[i].offset = SDL_JOYSTICK_AXIS_MIN - axis_min[i];
	joystick->hwdata->transaxis[i].scale =
	(float) (SDL_JOYSTICK_AXIS_MAX - SDL_JOYSTICK_AXIS_MIN) / (axis_max[i] - axis_min[i]);
	} else {
	joystick->hwdata->transaxis[i].offset = 0;
	joystick->hwdata->transaxis[i].scale = 1.0; /* Just in case */
	}
	}

	/* fill nbuttons, naxes, and nhats fields */
	joystick->nbuttons = SYS_Joystick[index].wNumButtons;
	joystick->naxes = SYS_Joystick[index].wNumAxes;
	if (SYS_Joystick[index].wCaps & JOYCAPS_HASPOV) {
	joystick->nhats = 1;
	} else {
	joystick->nhats = 0;
	}
	return (0);
	}

	static Uint8
	TranslatePOV(DWORD value)
	{
	Uint8 pos;

	pos = SDL_HAT_CENTERED;
	if (value != JOY_POVCENTERED) {
	if ((value > JOY_POVLEFT) \|\| (value < JOY_POVRIGHT)) {
	pos \|= SDL_HAT_UP;
	}
	if ((value > JOY_POVFORWARD) && (value < JOY_POVBACKWARD)) {
	pos \|= SDL_HAT_RIGHT;
	}
	if ((value > JOY_POVRIGHT) && (value < JOY_POVLEFT)) {
	pos \|= SDL_HAT_DOWN;
	}
	if (value > JOY_POVBACKWARD) {
	pos \|= SDL_HAT_LEFT;
	}
	}
	return (pos);
	}

	static int
	WINMM_JoystickRumble(SDL_Joystick *joystick, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble)
	{
	return SDL_Unsupported();
	}

	static int
	WINMM_JoystickRumbleTriggers(SDL_Joystick *joystick, Uint16 left_rumble, Uint16 right_rumble)
	{
	return SDL_Unsupported();
	}

	static SDL_bool WINMM_JoystickHasLED(SDL_Joystick *joystick)
	{
	return SDL_FALSE;
	}

	static int
	WINMM_JoystickSetLED(SDL_Joystick *joystick, Uint8 red, Uint8 green, Uint8 blue)
	{
	return SDL_Unsupported();
	}

	static int WINMM_JoystickSetSensorsEnabled(SDL_Joystick *joystick, SDL_bool enabled)
	{
	return SDL_Unsupported();
	}

	/* Function to update the state of a joystick - called as a device poll.
	* This function shouldn't update the joystick structure directly,
	* but instead should call SDL_PrivateJoystick*() to deliver events
	* and update joystick device state.
	*/
	static void
	WINMM_JoystickUpdate(SDL_Joystick * joystick)
	{
	MMRESULT result;
	int i;
	DWORD flags[MAX_AXES] = { JOY_RETURNX, JOY_RETURNY, JOY_RETURNZ,
	JOY_RETURNR, JOY_RETURNU, JOY_RETURNV
	};
	DWORD pos[MAX_AXES];
	struct _transaxis *transaxis;
	int value;
	JOYINFOEX joyinfo;

	joyinfo.dwSize = sizeof(joyinfo);
	joyinfo.dwFlags = JOY_RETURNALL \| JOY_RETURNPOVCTS;
	if (!joystick->hats) {
	joyinfo.dwFlags &= ~(JOY_RETURNPOV \| JOY_RETURNPOVCTS);
	}
	result = joyGetPosEx(joystick->hwdata->id, &joyinfo);
	if (result != JOYERR_NOERROR) {
	SetMMerror("joyGetPosEx", result);
	return;
	}

	/* joystick motion events */
	pos[0] = joyinfo.dwXpos;
	pos[1] = joyinfo.dwYpos;
	pos[2] = joyinfo.dwZpos;
	pos[3] = joyinfo.dwRpos;
	pos[4] = joyinfo.dwUpos;
	pos[5] = joyinfo.dwVpos;

	transaxis = joystick->hwdata->transaxis;
	for (i = 0; i < joystick->naxes; i++) {
	if (joyinfo.dwFlags & flags[i]) {
	value = (int) (((float) pos[i] + transaxis[i].offset) * transaxis[i].scale);
	SDL_PrivateJoystickAxis(joystick, (Uint8) i, (Sint16) value);
	}
	}

	/* joystick button events */
	if (joyinfo.dwFlags & JOY_RETURNBUTTONS) {
	for (i = 0; i < joystick->nbuttons; ++i) {
	if (joyinfo.dwButtons & JOY_BUTTON_FLAG(i)) {
	SDL_PrivateJoystickButton(joystick, (Uint8) i, SDL_PRESSED);
	} else {
	SDL_PrivateJoystickButton(joystick, (Uint8) i, SDL_RELEASED);
	}
	}
	}

	/* joystick hat events */
	if (joyinfo.dwFlags & JOY_RETURNPOV) {
	SDL_PrivateJoystickHat(joystick, 0, TranslatePOV(joyinfo.dwPOV));
	}
	}

	/* Function to close a joystick after use */
	static void
	WINMM_JoystickClose(SDL_Joystick * joystick)
	{
	SDL_free(joystick->hwdata);
	}

	/* Function to perform any system-specific joystick related cleanup */
	static void
	WINMM_JoystickQuit(void)
	{
	int i;
	for (i = 0; i < MAX_JOYSTICKS; i++) {
	SDL_free(SYS_JoystickName[i]);
	SYS_JoystickName[i] = NULL;
	}
	}

	static SDL_bool
	WINMM_JoystickGetGamepadMapping(int device_index, SDL_GamepadMapping *out)
	{
	return SDL_FALSE;
	}


	/* implementation functions */
	void
	SetMMerror(char *function, int code)
	{
	static char *error;
	static char errbuf[1024];

	errbuf[0] = 0;
	switch (code) {
	case MMSYSERR_NODRIVER:
	error = "Joystick driver not present";
	break;

	case MMSYSERR_INVALPARAM:
	case JOYERR_PARMS:
	error = "Invalid parameter(s)";
	break;

	case MMSYSERR_BADDEVICEID:
	error = "Bad device ID";
	break;

	case JOYERR_UNPLUGGED:
	error = "Joystick not attached";
	break;

	case JOYERR_NOCANDO:
	error = "Can't capture joystick input";
	break;

	default:
	SDL_snprintf(errbuf, SDL_arraysize(errbuf),
	"%s: Unknown Multimedia system error: 0x%x",
	function, code);
	break;
	}

	if (!errbuf[0]) {
	SDL_snprintf(errbuf, SDL_arraysize(errbuf), "%s: %s", function,
	error);
	}
	SDL_SetError("%s", errbuf);
	}

	SDL_JoystickDriver SDL_WINMM_JoystickDriver =
	{
	WINMM_JoystickInit,
	WINMM_NumJoysticks,
	WINMM_JoystickDetect,
	WINMM_JoystickGetDeviceName,
	WINMM_JoystickGetDevicePlayerIndex,
	WINMM_JoystickSetDevicePlayerIndex,
	WINMM_JoystickGetDeviceGUID,
	WINMM_JoystickGetDeviceInstanceID,
	WINMM_JoystickOpen,
	WINMM_JoystickRumble,
	WINMM_JoystickRumbleTriggers,
	WINMM_JoystickHasLED,
	WINMM_JoystickSetLED,
	WINMM_JoystickSetSensorsEnabled,
	WINMM_JoystickUpdate,
	WINMM_JoystickClose,
	WINMM_JoystickQuit,
	WINMM_JoystickGetGamepadMapping
	};

	#endif /* SDL_JOYSTICK_WINMM */

	/* vi: set ts=4 sw=4 expandtab: */