Reworked XInput and DirectInput joystick code.

Now multiple XInput controllers map correctly to device indexes instead of grabbing
the first available userid, and are completely separated out from DirectInput.

Also, the hardcoded limitation on number of DirectInput devices is gone. I don't
expect there to really ever be more than eight joysticks plugged into a machine, but
it was a leftover limitation for a static array we didn't actually use anymore.

Fixes Bugzilla #1984. (etc?)

src/joystick/SDL_gamecontroller.c

@@ -851,9 +851,6 @@ SDL_GameControllerOpen(int device_index)
     SDL_GameController *gamecontroller;
     SDL_GameController *gamecontrollerlist;
     ControllerMapping_t *pSupportedController = NULL;
-#ifdef SDL_JOYSTICK_DINPUT
-	SDL_bool bIsXinputDevice;
-#endif
 
     if ((device_index < 0) || (device_index >= SDL_NumJoysticks())) {
         SDL_SetError("There are %d joysticks available", SDL_NumJoysticks());
@@ -886,11 +883,6 @@ SDL_GameControllerOpen(int device_index)
         return NULL;
     }
 
-#ifdef SDL_JOYSTICK_DINPUT
-	/* check if we think we should open this device in XInput mode */
-	bIsXinputDevice = SDL_SYS_IsXInputDeviceIndex(device_index);
-#endif
-
     SDL_memset(gamecontroller, 0, (sizeof *gamecontroller));
     gamecontroller->joystick = SDL_JoystickOpen(device_index);
     if ( !gamecontroller->joystick ) {
@@ -898,19 +890,6 @@ SDL_GameControllerOpen(int device_index)
         return NULL;
     }
 
-#ifdef SDL_JOYSTICK_DINPUT
-	if ( !SDL_SYS_IsXInputJoystick( gamecontroller->joystick ) && bIsXinputDevice )
-	{
-		/* we tried to open the controller in XInput mode and failed, so get the mapping again for the direct input variant if possible */
-		SDL_JoystickGUID jGUID = SDL_JoystickGetDeviceGUID( device_index );
-		pSupportedController = SDL_PrivateGetControllerMappingForGUID(&jGUID);
-		if ( !pSupportedController ) {
-			SDL_SetError("Failed to open device in XInput mode (%d)", device_index );
-			return (NULL);
-		}
-	}
-#endif
-
     SDL_PrivateLoadButtonMapping( &gamecontroller->mapping, pSupportedController->guid, pSupportedController->name, pSupportedController->mapping );
 
     /* Add joystick to list */

src/joystick/windows/SDL_dxjoystick.c

@@ -55,7 +55,6 @@
 
 
 #define INPUT_QSIZE 32      /* Buffer up to 32 input messages */
-#define MAX_JOYSTICKS 8
 #define AXIS_MIN    -32768  /* minimum value for axis coordinate */
 #define AXIS_MAX    32767   /* maximum value for axis coordinate */
 #define JOY_AXIS_THRESHOLD  (((AXIS_MAX)-(AXIS_MIN))/100)   /* 1% motion */
@@ -70,7 +69,6 @@ static LPDIRECTINPUT8 dinput = NULL;
 static SDL_bool s_bDeviceAdded = SDL_FALSE;
 static SDL_bool s_bDeviceRemoved = SDL_FALSE;
 static SDL_JoystickID s_nInstanceID = -1;
-static GUID *s_pKnownJoystickGUIDs = NULL;
 static SDL_cond *s_condJoystickThread = NULL;
 static SDL_mutex *s_mutexJoyStickEnum = NULL;
 static SDL_Thread *s_threadJoystick = NULL;
@@ -481,10 +479,10 @@ SDL_JoystickThread(void *_data)
     HWND messageWindow = 0;
     HDEVNOTIFY hNotify = 0;
     DEV_BROADCAST_DEVICEINTERFACE dbh;
-    SDL_bool bOpenedXInputDevices[4];
+    SDL_bool bOpenedXInputDevices[SDL_XINPUT_MAX_DEVICES];
     WNDCLASSEX wincl;
 
-    SDL_memset( bOpenedXInputDevices, 0x0, sizeof(bOpenedXInputDevices) );
+    SDL_zero(bOpenedXInputDevices);
 
     WIN_CoInitialize();
 
@@ -505,7 +503,7 @@ SDL_JoystickThread(void *_data)
         return SDL_SetError("Failed to create message window for joystick autodetect.", GetLastError());
     }
 
-    SDL_memset(&dbh, 0x0, sizeof(dbh));
+    SDL_zero(dbh);
 
     dbh.dbcc_size = sizeof(dbh);
     dbh.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
@@ -521,9 +519,8 @@ SDL_JoystickThread(void *_data)
     while ( s_bJoystickThreadQuit == SDL_FALSE )
     {
         MSG messages;
-        Uint8 userId;
-        int nCurrentOpenedXInputDevices = 0;
-        int nNewOpenedXInputDevices = 0;
+        SDL_bool bXInputChanged = SDL_FALSE;
+
         SDL_CondWaitTimeout( s_condJoystickThread, s_mutexJoyStickEnum, 300 );
 
         while ( s_bJoystickThreadQuit == SDL_FALSE && PeekMessage(&messages, messageWindow, 0, 0, PM_NOREMOVE) )
@@ -534,33 +531,24 @@ SDL_JoystickThread(void *_data)
             }
         }
 
-        if ( s_bXInputEnabled && XINPUTGETCAPABILITIES )
-        {
+        if ( s_bXInputEnabled && XINPUTGETCAPABILITIES ) {
             /* scan for any change in XInput devices */
-            for ( userId = 0; userId < 4; userId++ )
-            {
+            Uint8 userId;
+            for (userId = 0; userId < SDL_XINPUT_MAX_DEVICES; userId++) {
                 XINPUT_CAPABILITIES capabilities;
-                DWORD result;
-
-                if ( bOpenedXInputDevices[userId] == SDL_TRUE )
-                    nCurrentOpenedXInputDevices++;
-
-                result = XINPUTGETCAPABILITIES( userId, XINPUT_FLAG_GAMEPAD, &capabilities );
-                if ( result == ERROR_SUCCESS )
-                {
-                    bOpenedXInputDevices[userId] = SDL_TRUE;
-                    nNewOpenedXInputDevices++;
-                }
-                else
-                {
-                    bOpenedXInputDevices[userId] = SDL_FALSE;
+                const DWORD result = XINPUTGETCAPABILITIES( userId, XINPUT_FLAG_GAMEPAD, &capabilities );
+                const SDL_bool available = (result == ERROR_SUCCESS);
+                if (bOpenedXInputDevices[userId] != available) {
+                    bXInputChanged = SDL_TRUE;
+                    bOpenedXInputDevices[userId] = available;
                 }
             }
         }
 
-        if ( s_pKnownJoystickGUIDs && ( s_bWindowsDeviceChanged || nNewOpenedXInputDevices != nCurrentOpenedXInputDevices ) )
-        {
+        if (s_bWindowsDeviceChanged || bXInputChanged) {
+            SDL_UnlockMutex( s_mutexJoyStickEnum );  /* let main thread go while we SDL_Delay(). */
             SDL_Delay( 300 ); /* wait for direct input to find out about this device */
+            SDL_LockMutex( s_mutexJoyStickEnum );
 
             s_bDeviceRemoved = SDL_TRUE;
             s_bDeviceAdded = SDL_TRUE;
@@ -625,14 +613,15 @@ SDL_SYS_JoystickInit(void)
         return SetDIerror("IDirectInput::Initialize", result);
     }
 
+    if ((s_bXInputEnabled) && (WIN_LoadXInputDLL() == -1)) {
+        s_bXInputEnabled = SDL_FALSE;  /* oh well. */
+    }
+
     s_mutexJoyStickEnum = SDL_CreateMutex();
     s_condJoystickThread = SDL_CreateCond();
     s_bDeviceAdded = SDL_TRUE; /* force a scan of the system for joysticks this first time */
-    SDL_SYS_JoystickDetect();
 
-    if ((s_bXInputEnabled) && (WIN_LoadXInputDLL() == -1)) {
-        s_bXInputEnabled = SDL_FALSE;  /* oh well. */
-    }
+    SDL_SYS_JoystickDetect();
 
     if ( !s_threadJoystick )
     {
@@ -662,15 +651,17 @@ int SDL_SYS_NumJoysticks()
     return nJoysticks;
 }
 
-static int s_iNewGUID = 0;
-
 /* helper function for direct input, gets called for each connected joystick */
 static BOOL CALLBACK
     EnumJoysticksCallback(const DIDEVICEINSTANCE * pdidInstance, VOID * pContext)
 {
     JoyStick_DeviceData *pNewJoystick;
     JoyStick_DeviceData *pPrevJoystick = NULL;
-    SDL_bool bXInputDevice;
+
+    if (SDL_IsXInputDevice( &pdidInstance->guidProduct )) {
+        return DIENUM_CONTINUE;  /* ignore XInput devices here, keep going. */
+    }
+
     pNewJoystick = *(JoyStick_DeviceData **)pContext;
     while ( pNewJoystick )
     {
@@ -689,58 +680,107 @@ static BOOL CALLBACK
             pNewJoystick->pNext = SYS_Joystick;
             SYS_Joystick = pNewJoystick;
 
-            s_pKnownJoystickGUIDs[ s_iNewGUID ] = pdidInstance->guidInstance;
-            s_iNewGUID++;
-            if ( s_iNewGUID < MAX_JOYSTICKS )
-                return DIENUM_CONTINUE; /* already have this joystick loaded, just keep going */
-            else
-                return DIENUM_STOP;
+            return DIENUM_CONTINUE; /* already have this joystick loaded, just keep going */
         }
 
         pPrevJoystick = pNewJoystick;
         pNewJoystick = pNewJoystick->pNext;
     }
 
-    s_bDeviceAdded = SDL_TRUE;
-
-    bXInputDevice = SDL_IsXInputDevice( &pdidInstance->guidProduct );
-
     pNewJoystick = (JoyStick_DeviceData *)SDL_malloc( sizeof(JoyStick_DeviceData) );
-
-    if ( bXInputDevice )
-    {
-        pNewJoystick->bXInputDevice = SDL_TRUE;
-        pNewJoystick->XInputUserId = INVALID_XINPUT_USERID;
+    if (!pNewJoystick) {
+        return DIENUM_CONTINUE; /* better luck next time? */
     }
-    else
-    {
-        pNewJoystick->bXInputDevice = SDL_FALSE;
+
+    SDL_zerop(pNewJoystick);
+    pNewJoystick->joystickname = WIN_StringToUTF8(pdidInstance->tszProductName);
+    if (!pNewJoystick->joystickname) {
+        SDL_free(pNewJoystick);
+        return DIENUM_CONTINUE; /* better luck next time? */
     }
 
     SDL_memcpy(&(pNewJoystick->dxdevice), pdidInstance,
         sizeof(DIDEVICEINSTANCE));
 
-    pNewJoystick->joystickname = WIN_StringToUTF8(pdidInstance->tszProductName);
+    pNewJoystick->XInputUserId = INVALID_XINPUT_USERID;
     pNewJoystick->send_add_event = 1;
     pNewJoystick->nInstanceID = ++s_nInstanceID;
     SDL_memcpy( &pNewJoystick->guid, &pdidInstance->guidProduct, sizeof(pNewJoystick->guid) );
-    pNewJoystick->pNext = NULL;
+    pNewJoystick->pNext = SYS_Joystick;
+    SYS_Joystick = pNewJoystick;
 
-    if ( SYS_Joystick )
-    {
-        pNewJoystick->pNext = SYS_Joystick;
+    s_bDeviceAdded = SDL_TRUE;
+
+    return DIENUM_CONTINUE; /* get next device, please */
+}
+
+static void
+AddXInputDevice(const Uint8 userid, JoyStick_DeviceData **pContext)
+{
+    char name[32];
+    JoyStick_DeviceData *pPrevJoystick = NULL;
+    JoyStick_DeviceData *pNewJoystick = *pContext;
+
+    while (pNewJoystick) {
+        if ((pNewJoystick->bXInputDevice) && (pNewJoystick->XInputUserId == userid)) {
+            /* if we are replacing the front of the list then update it */
+            if (pNewJoystick == *pContext) {
+                *pContext = pNewJoystick->pNext;
+            } else if (pPrevJoystick) {
+                pPrevJoystick->pNext = pNewJoystick->pNext;
+            }
+
+            pNewJoystick->pNext = SYS_Joystick;
+            SYS_Joystick = pNewJoystick;
+        }
+
+        pPrevJoystick = pNewJoystick;
+        pNewJoystick = pNewJoystick->pNext;
+        return;   /* already in the list. */
     }
+
+    pNewJoystick = (JoyStick_DeviceData *) SDL_malloc(sizeof (JoyStick_DeviceData));
+    if (!pNewJoystick) {
+        return; /* better luck next time? */
+    }
+    SDL_zerop(pNewJoystick);
+
+    SDL_snprintf(name, sizeof (name), "XInput Controller #%d", (int) userid);
+    pNewJoystick->joystickname = SDL_strdup(name);
+    if (!pNewJoystick->joystickname) {
+        SDL_free(pNewJoystick);
+        return; /* better luck next time? */
+    }
+
+    pNewJoystick->bXInputDevice = SDL_TRUE;
+    pNewJoystick->XInputUserId = userid;
+    pNewJoystick->send_add_event = 1;
+    pNewJoystick->nInstanceID = ++s_nInstanceID;
+    pNewJoystick->pNext = SYS_Joystick;
     SYS_Joystick = pNewJoystick;
 
-    s_pKnownJoystickGUIDs[ s_iNewGUID ] = pdidInstance->guidInstance;
-    s_iNewGUID++;
+    s_bDeviceAdded = SDL_TRUE;
+}
 
-    if ( s_iNewGUID < MAX_JOYSTICKS )
-        return DIENUM_CONTINUE; /* already have this joystick loaded, just keep going */
-    else
-        return DIENUM_STOP;
+static void
+EnumXInputDevices(JoyStick_DeviceData **pContext)
+{
+    if (s_bXInputEnabled) {
+        Uint8 userid;
+        for (userid = 0; userid < SDL_XINPUT_MAX_DEVICES; userid++) {
+            XINPUT_CAPABILITIES capabilities;
+            if (XINPUTGETCAPABILITIES(userid, XINPUT_FLAG_GAMEPAD, &capabilities) == ERROR_SUCCESS) {
+                /* Current version of XInput mistakenly returns 0 as the Type. Ignore it and ensure the subtype is a gamepad. */
+                /* !!! FIXME: we might want to support steering wheels or guitars or whatever laster. */
+                if (capabilities.SubType == XINPUT_DEVSUBTYPE_GAMEPAD) {
+                    AddXInputDevice(userid, pContext);
+                }
+            }
+        }
+    }
 }
 
+
 /* detect any new joysticks being inserted into the system */
 void SDL_SYS_JoystickDetect()
 {
@@ -748,27 +788,26 @@ void SDL_SYS_JoystickDetect()
     /* only enum the devices if the joystick thread told us something changed */
     if ( s_bDeviceAdded || s_bDeviceRemoved )
     {
+        SDL_LockMutex( s_mutexJoyStickEnum );
+
         s_bDeviceAdded = SDL_FALSE;
         s_bDeviceRemoved = SDL_FALSE;
 
         pCurList = SYS_Joystick;
         SYS_Joystick = NULL;
-        s_iNewGUID = 0;
-        SDL_LockMutex( s_mutexJoyStickEnum );
 
-        if ( !s_pKnownJoystickGUIDs )
-            s_pKnownJoystickGUIDs = SDL_malloc( sizeof(GUID)*MAX_JOYSTICKS );
+        /* Look for XInput devices... */
+        EnumXInputDevices(&pCurList);
 
-        SDL_memset( s_pKnownJoystickGUIDs, 0x0, sizeof(GUID)*MAX_JOYSTICKS );
-
-        /* Look for joysticks, wheels, head trackers, gamepads, etc.. */
+        /* Look for DirectInput joysticks, wheels, head trackers, gamepads, etc.. */
         IDirectInput8_EnumDevices(dinput,
             DI8DEVCLASS_GAMECTRL,
             EnumJoysticksCallback,
             &pCurList, DIEDFL_ATTACHEDONLY);
 
-        SDL_free(SDL_RawDevList);  /* in case we used this. */
+        SDL_free(SDL_RawDevList);  /* in case we used this in DirectInput enumerator. */
         SDL_RawDevList = NULL;
+        SDL_RawDevListCount = 0;
 
         SDL_UnlockMutex( s_mutexJoyStickEnum );
     }
@@ -872,17 +911,11 @@ int
 SDL_SYS_JoystickOpen(SDL_Joystick * joystick, int device_index)
 {
     HRESULT result;
-    LPDIRECTINPUTDEVICE8 device;
-    DIPROPDWORD dipdw;
     JoyStick_DeviceData *joystickdevice = SYS_Joystick;
 
     for (; device_index > 0; device_index--)
         joystickdevice = joystickdevice->pNext;
 
-    SDL_memset(&dipdw, 0, sizeof(DIPROPDWORD));
-    dipdw.diph.dwSize = sizeof(DIPROPDWORD);
-    dipdw.diph.dwHeaderSize = sizeof(DIPROPHEADER);
-
     /* allocate memory for system specific hardware data */
     joystick->instance_id = joystickdevice->nInstanceID;
     joystick->closed = 0;
@@ -891,97 +924,50 @@ SDL_SYS_JoystickOpen(SDL_Joystick * joystick, int device_index)
     if (joystick->hwdata == NULL) {
         return SDL_OutOfMemory();
     }
-    SDL_memset(joystick->hwdata, 0, sizeof(struct joystick_hwdata));
-    joystick->hwdata->buffered = 1;
-    joystick->hwdata->removed = 0;
-    joystick->hwdata->Capabilities.dwSize = sizeof(DIDEVCAPS);
-    joystick->hwdata->guid = joystickdevice->guid;
+    SDL_zerop(joystick->hwdata);
 
-    if ( joystickdevice->bXInputDevice )
-    {
+    if (joystickdevice->bXInputDevice) {
+        const SDL_bool bIs14OrLater = (SDL_XInputVersion >= ((1<<16)|4));
+        const Uint8 userId = joystickdevice->XInputUserId;
         XINPUT_CAPABILITIES capabilities;
-        Uint8 userId = 0;
-        DWORD result;
-        JoyStick_DeviceData *joysticklist = SYS_Joystick;
-        /* scan the opened joysticks and pick the next free xinput userid for this one */
-        for( ; joysticklist; joysticklist = joysticklist->pNext)
-        {
-            if ( joysticklist->bXInputDevice && joysticklist->XInputUserId == userId )
-                userId++;
-        }
 
-        if ( s_bXInputEnabled && XINPUTGETCAPABILITIES )
-        {
-			while ( 1 )
-			{
-				result = XINPUTGETCAPABILITIES( userId, XINPUT_FLAG_GAMEPAD, &capabilities );
-				if ( result == ERROR_SUCCESS )
-				{
-					const SDL_bool bIs14OrLater = (SDL_XInputVersion >= ((1<<16)|4));
-					SDL_bool bIsSupported = SDL_FALSE;
-					/* Current version of XInput mistakenly returns 0 as the Type. Ignore it and ensure the subtype is a gamepad. */
-					bIsSupported = ( capabilities.SubType == XINPUT_DEVSUBTYPE_GAMEPAD );
-
-					if ( !bIsSupported )
-					{
-						joystickdevice->bXInputDevice = SDL_FALSE;
-					}
-					else
-					{
-						/* valid */
-						joystick->hwdata->bXInputDevice = SDL_TRUE;
-						if ((!bIs14OrLater) || (capabilities.Flags & XINPUT_CAPS_FFB_SUPPORTED)) {
-							joystick->hwdata->bXInputHaptic = SDL_TRUE;
-						}
-						SDL_memset( joystick->hwdata->XInputState, 0x0, sizeof(joystick->hwdata->XInputState) );
-						joystickdevice->XInputUserId = userId;
-						joystick->hwdata->userid = userId;
-						joystick->hwdata->currentXInputSlot = 0;
-						/* The XInput API has a hard coded button/axis mapping, so we just match it */
-						joystick->naxes = 6;
-						joystick->nbuttons = 15;
-						joystick->nballs = 0;
-						joystick->nhats = 0;
-					}
-					break;
-				}
-				else
-				{
-					if ( userId < XUSER_MAX_COUNT && result == ERROR_DEVICE_NOT_CONNECTED )
-					{
-						/* scan the opened joysticks and pick the next free xinput userid for this one */
-						++userId;
-
-						joysticklist = SYS_Joystick;
-						for( ; joysticklist; joysticklist = joysticklist->pNext)
-						{
-							if ( joysticklist->bXInputDevice && joysticklist->XInputUserId == userId )
-								userId++;
-						}
-
-						if ( userId >= XUSER_MAX_COUNT )
-						{
-							joystickdevice->bXInputDevice = SDL_FALSE;
-							break;
-						}
-					}
-					else
-					{
-						joystickdevice->bXInputDevice = SDL_FALSE;
-						break;
-					}
-				}
-			}
-        }
-        else
-        {
-            joystickdevice->bXInputDevice = SDL_FALSE;
-        }
-    }
-
-    if ( joystickdevice->bXInputDevice == SDL_FALSE )
-    {
-        joystick->hwdata->bXInputDevice = SDL_FALSE;
+        SDL_assert(s_bXInputEnabled);
+        SDL_assert(XINPUTGETCAPABILITIES);
+        SDL_assert(userId >= 0);
+        SDL_assert(userId < SDL_XINPUT_MAX_DEVICES);
+
+        joystick->hwdata->bXInputDevice = SDL_TRUE;
+
+        if (XINPUTGETCAPABILITIES(userId, XINPUT_FLAG_GAMEPAD, &capabilities) != ERROR_SUCCESS) {
+            SDL_free(joystick->hwdata);
+            joystick->hwdata = NULL;
+            return SDL_SetError("Failed to obtain XInput device capabilities. Device disconnected?");
+        } else {
+            /* Current version of XInput mistakenly returns 0 as the Type. Ignore it and ensure the subtype is a gamepad. */
+            SDL_assert(capabilities.SubType == XINPUT_DEVSUBTYPE_GAMEPAD);
+            if ((!bIs14OrLater) || (capabilities.Flags & XINPUT_CAPS_FFB_SUPPORTED)) {
+                joystick->hwdata->bXInputHaptic = SDL_TRUE;
+            }
+            joystick->hwdata->userid = userId;
+
+            /* The XInput API has a hard coded button/axis mapping, so we just match it */
+            joystick->naxes = 6;
+            joystick->nbuttons = 15;
+            joystick->nballs = 0;
+            joystick->nhats = 0;
+		}
+    } else {  /* use DirectInput, not XInput. */
+        LPDIRECTINPUTDEVICE8 device;
+        DIPROPDWORD dipdw;
+
+        joystick->hwdata->buffered = 1;
+        joystick->hwdata->removed = 0;
+        joystick->hwdata->Capabilities.dwSize = sizeof(DIDEVCAPS);
+        joystick->hwdata->guid = joystickdevice->guid;
+
+        SDL_zero(dipdw);
+        dipdw.diph.dwSize = sizeof(DIPROPDWORD);
+        dipdw.diph.dwHeaderSize = sizeof(DIPROPHEADER);
 
         result =
             IDirectInput8_CreateDevice(dinput,
@@ -1633,18 +1619,11 @@ SDL_SYS_JoystickQuit(void)
         coinitialized = SDL_FALSE;
     }
 
-    if ( s_pKnownJoystickGUIDs )
-    {
-        SDL_free( s_pKnownJoystickGUIDs );
-        s_pKnownJoystickGUIDs = NULL;
-    }
-
     if (s_bXInputEnabled) {
         WIN_UnloadXInputDLL();
     }
 }
 
-
 /* return the stable device guid for this device index */
 SDL_JoystickGUID SDL_SYS_JoystickGetDeviceGUID( int device_index )
 {