Added SDL_GameControllerMappingForDeviceIndex() to get the mapping for a controller before it's opened

WhatsNew.txt

@@ -1,6 +1,14 @@
 
 This is a list of major changes in SDL's version history.
 
+---------------------------------------------------------------------------
+2.0.9:
+---------------------------------------------------------------------------
+
+General:
+* Added SDL_GameControllerMappingForDeviceIndex() to get the mapping for a controller before it's opened
+
+
 ---------------------------------------------------------------------------
 2.0.8:
 ---------------------------------------------------------------------------

include/SDL_gamecontroller.h

@@ -175,6 +175,14 @@ extern DECLSPEC SDL_bool SDLCALL SDL_IsGameController(int joystick_index);
  */
 extern DECLSPEC const char *SDLCALL SDL_GameControllerNameForIndex(int joystick_index);
 
+/**
+ *  Get the mapping of a game controller.
+ *  This can be called before any controllers are opened.
+ *
+ *  \return the mapping string.  Must be freed with SDL_free().  Returns NULL if no mapping is available
+ */
+extern DECLSPEC char *SDLCALL SDL_GameControllerMappingForDeviceIndex(int joystick_index);
+
 /**
  *  Open a game controller for use.
  *  The index passed as an argument refers to the N'th game controller on the system.

src/dynapi/SDL_dynapi_overrides.h

@@ -669,3 +669,4 @@
 #define SDL_WinRTGetDeviceFamily SDL_WinRTGetDeviceFamily_REAL
 #define SDL_log10 SDL_log10_REAL
 #define SDL_log10f SDL_log10f_REAL
+#define SDL_GameControllerMappingForDeviceIndex SDL_GameControllerMappingForDeviceIndex_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -707,3 +707,4 @@ SDL_DYNAPI_PROC(SDL_bool,SDL_IsAndroidTV,(void),(),return)
 #endif
 SDL_DYNAPI_PROC(double,SDL_log10,(double a),(a),return)
 SDL_DYNAPI_PROC(float,SDL_log10f,(float a),(a),return)
+SDL_DYNAPI_PROC(char*,SDL_GameControllerMappingForDeviceIndex,(int a),(a),return)

src/joystick/SDL_gamecontroller.c

@@ -425,6 +425,12 @@ static ControllerMapping_t *SDL_PrivateGetControllerMappingForGUID(SDL_JoystickG
         }
         pSupportedController = pSupportedController->next;
     }
+#if SDL_JOYSTICK_XINPUT
+    if (guid->data[14] == 'x') {
+        /* This is an XInput device */
+        return s_pXInputMapping;
+    }
+#endif
     return NULL;
 }
 
@@ -1033,11 +1039,6 @@ static ControllerMapping_t *SDL_PrivateGetControllerMapping(int device_index)
     name = SDL_JoystickNameForIndex(device_index);
     guid = SDL_JoystickGetDeviceGUID(device_index);
     mapping = SDL_PrivateGetControllerMappingForNameAndGUID(name, guid);
-#if SDL_JOYSTICK_XINPUT
-    if (!mapping && SDL_SYS_IsXInputGamepad_DeviceIndex(device_index)) {
-        mapping = s_pXInputMapping;
-    }
-#endif
     SDL_UnlockJoysticks();
     return mapping;
 }
@@ -1374,6 +1375,40 @@ SDL_GameControllerNameForIndex(int device_index)
 }
 
 
+/**
+ *  Get the mapping of a game controller.
+ *  This can be called before any controllers are opened.
+ *  If no mapping can be found, this function returns NULL.
+ */
+char *
+SDL_GameControllerMappingForDeviceIndex(int joystick_index)
+{
+    char *pMappingString = NULL;
+    ControllerMapping_t *mapping;
+
+    SDL_LockJoysticks();
+    mapping = SDL_PrivateGetControllerMapping(joystick_index);
+    if (mapping) {
+        SDL_JoystickGUID guid;
+        char pchGUID[33];
+        size_t needed;
+        guid = SDL_JoystickGetDeviceGUID(joystick_index);
+        SDL_JoystickGetGUIDString(guid, pchGUID, sizeof(pchGUID));
+        /* allocate enough memory for GUID + ',' + name + ',' + mapping + \0 */
+        needed = SDL_strlen(pchGUID) + 1 + SDL_strlen(mapping->name) + 1 + SDL_strlen(mapping->mapping) + 1;
+        pMappingString = SDL_malloc(needed);
+        if (!pMappingString) {
+            SDL_OutOfMemory();
+            SDL_UnlockJoysticks();
+            return NULL;
+        }
+        SDL_snprintf(pMappingString, needed, "%s,%s,%s", pchGUID, mapping->name, mapping->mapping);
+    }
+    SDL_UnlockJoysticks();
+    return pMappingString;
+}
+
+
 /*
  * Return 1 if the joystick with this name and GUID is a supported controller
  */

src/joystick/SDL_sysjoystick.h

@@ -121,11 +121,6 @@ extern SDL_JoystickGUID SDL_SYS_JoystickGetDeviceGUID(int device_index);
 /* Function to return the stable GUID for a opened joystick */
 extern SDL_JoystickGUID SDL_SYS_JoystickGetGUID(SDL_Joystick * joystick);
 
-#if SDL_JOYSTICK_XINPUT
-/* Function returns SDL_TRUE if this device is an XInput gamepad */
-extern SDL_bool SDL_SYS_IsXInputGamepad_DeviceIndex(int device_index);
-#endif
-
 #endif /* SDL_sysjoystick_h_ */
 
 /* vi: set ts=4 sw=4 expandtab: */

src/joystick/windows/SDL_xinputjoystick.c

@@ -464,18 +464,6 @@ SDL_XINPUT_JoystickQuit(void)
     }
 }
 
-SDL_bool
-SDL_SYS_IsXInputGamepad_DeviceIndex(int device_index)
-{
-    JoyStick_DeviceData *device = SYS_Joystick;
-    int index;
-
-    for (index = device_index; index > 0; index--)
-        device = device->pNext;
-
-    return device->bXInputDevice;
-}
-
 #else /* !SDL_JOYSTICK_XINPUT */
 
 typedef struct JoyStick_DeviceData JoyStick_DeviceData;