WinRT: added preliminary joystick / game controller support (minus hotplugging)
authorDavid Ludwig <dludwig@pobox.com>
Sun, 19 May 2013 23:30:34 -0400
changeset 8471 456c005ec72c
parent 8470 705d8db7644c
child 8472 53cfc3c75475
WinRT: added preliminary joystick / game controller support (minus hotplugging)
VisualC-WinRT/SDL/SDL_VS2012-WinRT.vcxproj
VisualC-WinRT/SDL/SDL_VS2012-WinRT.vcxproj.filters
include/SDL_config_windowsrt.h
src/joystick/SDL_gamecontroller.c
src/joystick/SDL_sysjoystick.h
src/joystick/windowsrt/SDL_xinputjoystick.c
--- a/VisualC-WinRT/SDL/SDL_VS2012-WinRT.vcxproj	Sun May 12 22:38:39 2013 -0400
+++ b/VisualC-WinRT/SDL/SDL_VS2012-WinRT.vcxproj	Sun May 19 23:30:34 2013 -0400
@@ -75,9 +75,9 @@
     <ClCompile Include="..\..\src\file\SDL_rwops.c" />
     <ClCompile Include="..\..\src\haptic\dummy\SDL_syshaptic.c" />
     <ClCompile Include="..\..\src\haptic\SDL_haptic.c" />
-    <ClCompile Include="..\..\src\joystick\dummy\SDL_sysjoystick.c" />
     <ClCompile Include="..\..\src\joystick\SDL_gamecontroller.c" />
     <ClCompile Include="..\..\src\joystick\SDL_joystick.c" />
+    <ClCompile Include="..\..\src\joystick\windowsrt\SDL_xinputjoystick.c" />
     <ClCompile Include="..\..\src\loadso\windows\SDL_sysloadso.c" />
     <ClCompile Include="..\..\src\render\direct3d11\SDL_render_d3d11.cpp">
       <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">true</CompileAsWinRT>
@@ -426,7 +426,7 @@
       <SubSystem>Console</SubSystem>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
@@ -440,7 +440,7 @@
       <SubSystem>Console</SubSystem>
       <IgnoreAllDefaultLibraries>false</IgnoreAllDefaultLibraries>
       <GenerateWindowsMetadata>false</GenerateWindowsMetadata>
-      <AdditionalDependencies>xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
+      <AdditionalDependencies>xinput.lib;xaudio2.lib;d2d1.lib;d3d11.lib;dxgi.lib;ole32.lib;windowscodecs.lib;dwrite.lib;kernel32.lib;%(AdditionalDependencies)</AdditionalDependencies>
     </Link>
   </ItemDefinitionGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|arm'">
--- a/VisualC-WinRT/SDL/SDL_VS2012-WinRT.vcxproj.filters	Sun May 12 22:38:39 2013 -0400
+++ b/VisualC-WinRT/SDL/SDL_VS2012-WinRT.vcxproj.filters	Sun May 19 23:30:34 2013 -0400
@@ -192,9 +192,6 @@
     <ClCompile Include="..\..\src\haptic\dummy\SDL_syshaptic.c">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="..\..\src\joystick\dummy\SDL_sysjoystick.c">
-      <Filter>Source Files</Filter>
-    </ClCompile>
     <ClCompile Include="..\..\src\loadso\windows\SDL_sysloadso.c">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -267,6 +264,9 @@
     <ClCompile Include="..\..\src\joystick\SDL_gamecontroller.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\joystick\windowsrt\SDL_xinputjoystick.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\include\begin_code.h">
--- a/include/SDL_config_windowsrt.h	Sun May 12 22:38:39 2013 -0400
+++ b/include/SDL_config_windowsrt.h	Sun May 19 23:30:34 2013 -0400
@@ -144,8 +144,12 @@
 /* Enable various input drivers */
 // TODO, WinRT: Get haptic support working
 #define SDL_HAPTIC_DISABLED	1
-// TODO, WinRT: Get joystick support working
-#define SDL_JOYSTICK_DISABLED	1
+
+#if WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP
+#define SDL_JOYSTICK_DISABLED 1
+#else
+#define SDL_JOYSTICK_XINPUT 1
+#endif
 
 /* Enable various shared object loading systems */
 #define SDL_LOADSO_WINDOWS	1
--- a/src/joystick/SDL_gamecontroller.c	Sun May 12 22:38:39 2013 -0400
+++ b/src/joystick/SDL_gamecontroller.c	Sun May 19 23:30:34 2013 -0400
@@ -89,8 +89,10 @@
 /* default mappings we support */
 const char *s_ControllerMappings [] =
 {
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
+	"xinput,X360 Controller,a:b10,b:b11,y:b13,x:b12,start:b4,guide:b14,back:b5,dpup:b0,dpleft:b2,dpdown:b1,dpright:b3,leftshoulder:b8,rightshoulder:b9,leftstick:b6,rightstick:b7,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5",
+#endif
 #ifdef SDL_JOYSTICK_DINPUT
-	"xinput,X360 Controller,a:b10,b:b11,y:b13,x:b12,start:b4,guide:b14,back:b5,dpup:b0,dpleft:b2,dpdown:b1,dpright:b3,leftshoulder:b8,rightshoulder:b9,leftstick:b6,rightstick:b7,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:a4,righttrigger:a5",
 	"341a3608000000000000504944564944,Afterglow PS3 Controller,a:b1,b:b2,y:b3,x:b0,start:b9,guide:b12,back:b8,dpup:h0.1,dpleft:h0.8,dpdown:h0.4,dpright:h0.2,leftshoulder:b4,rightshoulder:b5,leftstick:b10,rightstick:b11,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:b6,righttrigger:b7",
 	"88880803000000000000504944564944,PS3 Controller,a:b2,b:b1,x:b0,y:b3,start:b11,back:b8,leftstick:b9,rightstick:b10,leftshoulder:b4,rightshoulder:b5,dpup:h0.1,dpleft:h0.4,dpdown:h0.8,dpright:h0.2,leftx:a0,lefty:a1,rightx:a3,righty:a4,lefttrigger:b6,righttrigger:b7,guide:b12",
 	"4c056802000000000000504944564944,PS3 Controller,a:b14,b:b13,y:b12,x:b15,start:b3,guide:b16,back:b0,leftstick:b1,rightstick:b2,leftshoulder:b10,rightshoulder:b11,dpup:b4,dpleft:b7,dpdown:b6,dpright:b5,leftx:a0,lefty:a1,rightx:a2,righty:a3,lefttrigger:b8,righttrigger:b9,",
@@ -119,7 +121,7 @@
 };
 
 static ControllerMapping_t *s_pSupportedControllers = NULL;
-#ifdef SDL_JOYSTICK_DINPUT
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
 static ControllerMapping_t *s_pXInputMapping = NULL;
 #endif
 
@@ -310,7 +312,7 @@
  */
 ControllerMapping_t *SDL_PrivateGetControllerMapping(int device_index)
 {
-#ifdef SDL_JOYSTICK_DINPUT
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
 	if ( SDL_SYS_IsXInputDeviceIndex(device_index) && s_pXInputMapping )
 	{
 		return s_pXInputMapping;
@@ -699,7 +701,7 @@
 	char *pchMapping;
     SDL_JoystickGUID jGUID;
     ControllerMapping_t *pControllerMapping;
-#ifdef SDL_JOYSTICK_DINPUT
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
     SDL_bool is_xinput_mapping = SDL_FALSE;
 #endif
 
@@ -707,7 +709,7 @@
     if (!pchGUID) {
         return -1;
     }
-#ifdef SDL_JOYSTICK_DINPUT
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
     if ( !SDL_strcasecmp( pchGUID, "xinput" ) ) {
         is_xinput_mapping = SDL_TRUE;
     }
@@ -742,7 +744,7 @@
 			SDL_free( pchMapping );
 			return SDL_OutOfMemory();
 		}
-#ifdef SDL_JOYSTICK_DINPUT
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
 		if ( is_xinput_mapping )
 		{
 			s_pXInputMapping = pControllerMapping;
--- a/src/joystick/SDL_sysjoystick.h	Sun May 12 22:38:39 2013 -0400
+++ b/src/joystick/SDL_sysjoystick.h	Sun May 19 23:30:34 2013 -0400
@@ -108,7 +108,7 @@
 /* Function to return the stable GUID for a opened joystick */
 extern SDL_JoystickGUID SDL_SYS_JoystickGetGUID(SDL_Joystick * joystick);
 
-#ifdef SDL_JOYSTICK_DINPUT
+#if defined(SDL_JOYSTICK_DINPUT) || defined(SDL_JOYSTICK_XINPUT)
 /* Function to get the current instance id of the joystick located at device_index */
 extern SDL_bool SDL_SYS_IsXInputDeviceIndex( int device_index );
 #endif
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/joystick/windowsrt/SDL_xinputjoystick.c	Sun May 19 23:30:34 2013 -0400
@@ -0,0 +1,378 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2013 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_config.h"
+
+#if SDL_JOYSTICK_XINPUT
+
+/* SDL_xinputjoystick.c implements an XInput-only joystick and game controller
+   backend that is suitable for use on WinRT.  SDL's DirectInput backend, also
+   XInput-capable, was not used as DirectInput is not available on WinRT (or,
+   at least, it isn't a public API).  Some portions of this XInput backend
+   may copy parts of the XInput-using code from the DirectInput backend.
+   Refactoring the common parts into one location may be good to-do at some
+   point.
+
+   TODO, WinRT: add hotplug support for XInput based game controllers
+*/
+
+#include "SDL_joystick.h"
+#include "../SDL_sysjoystick.h"
+#include "../SDL_joystick_c.h"
+#include "SDL_events.h"
+
+#include <Windows.h>
+#include <Xinput.h>
+
+struct joystick_hwdata {
+    //Uint8 bXInputHaptic; // Supports force feedback via XInput.
+    DWORD userIndex;    // The XInput device index, in the range [0, XUSER_MAX_COUNT-1] (probably [0,3]).
+    XINPUT_STATE XInputState;   // the last-read in XInputState, kept around to compare old and new values
+    SDL_bool isDeviceConnected; // was the device connected (on the last polling, or during backend-initialization)?
+};
+
+/* Keep track of data on all XInput devices, regardless of whether or not
+   they've been opened (via SDL_JoystickOpen).
+ */
+static struct joystick_hwdata g_XInputData[XUSER_MAX_COUNT];
+
+/* Function to scan the system for joysticks.
+ * It should return 0, or -1 on an unrecoverable fatal error.
+ */
+int
+SDL_SYS_JoystickInit(void)
+{
+    HRESULT result = S_OK;
+    XINPUT_STATE tempXInputState;
+    int i;
+
+    SDL_zero(g_XInputData);
+
+    /* Make initial notes on whether or not devices are connected (or not).
+     */
+    for (i = 0; i < XUSER_MAX_COUNT; ++i) {
+        result = XInputGetState(i, &tempXInputState);
+        if (result == ERROR_SUCCESS) {
+            g_XInputData[i].isDeviceConnected = SDL_TRUE;
+        }
+    }
+
+    return (0);
+}
+
+int SDL_SYS_NumJoysticks()
+{
+    int joystickCount = 0;
+    DWORD i;
+
+    /* Iterate through each possible XInput device and see if something
+       was connected (at joystick init, or during the last polling).
+     */
+    for (i = 0; i < XUSER_MAX_COUNT; ++i) {
+        if (g_XInputData[i].isDeviceConnected) {
+            ++joystickCount;
+        }
+    }
+
+    return joystickCount;
+}
+
+void SDL_SYS_JoystickDetect()
+{
+}
+
+SDL_bool SDL_SYS_JoystickNeedsPolling()
+{
+    return SDL_FALSE;
+}
+
+/* Internal function to retreive device capabilities.
+   This function will return an SDL-standard value of 0 on success
+   (a device is connected, and data on it was retrieved), or -1
+   on failure (no device was connected, or some other error
+   occurred.  SDL_SetError() will be invoked to set an appropriate
+   error message.
+ */
+static int
+SDL_XInput_GetDeviceCapabilities(int device_index, XINPUT_CAPABILITIES * pDeviceCaps)
+{
+    HRESULT dwResult;
+
+    /* Make sure that the device index is a valid one.  If not, return to the
+       caller with an error.
+     */
+    if (device_index < 0 || device_index >= XUSER_MAX_COUNT) {
+        return SDL_SetError("invalid/unavailable device index");
+    }
+
+    /* See if a device exists, and if so, what its capabilities are.  If a
+       device is not available, return to the caller with an error.
+     */
+    switch ((dwResult = XInputGetCapabilities(device_index, 0, pDeviceCaps))) {
+        case ERROR_SUCCESS:
+            /* A device is available, and its capabilities were retrieved! */
+            return 0;
+        case ERROR_DEVICE_NOT_CONNECTED:
+            return SDL_SetError("no device is connected at joystick index, %d", device_index);
+        default:
+            return SDL_SetError("an unknown error occurred when retrieving info on a device at joystick index, %d", device_index);
+    }
+}
+
+/* Function to get the device-dependent name of a joystick */
+const char *
+SDL_SYS_JoystickNameForDeviceIndex(int device_index)
+{
+    XINPUT_CAPABILITIES deviceCaps;
+
+    if (SDL_XInput_GetDeviceCapabilities(device_index, &deviceCaps) != 0) {
+        /* Uh oh.  Device capabilities couldn't be retrieved.  Return to the
+           caller.  SDL_SetError() has already been invoked (with relevant
+           information).
+         */
+        return NULL;
+    }
+
+    switch (deviceCaps.SubType) {
+        default:
+            if (deviceCaps.Type == XINPUT_DEVTYPE_GAMEPAD) {
+                return "Undefined game controller";
+            } else {
+                return "Undefined controller";
+            }
+        case XINPUT_DEVSUBTYPE_UNKNOWN:
+            if (deviceCaps.Type == XINPUT_DEVTYPE_GAMEPAD) {
+                return "Unknown game controller";
+            } else {
+                return "Unknown controller";
+            }
+        case XINPUT_DEVSUBTYPE_GAMEPAD:
+            return "Gamepad controller";
+        case XINPUT_DEVSUBTYPE_WHEEL:
+            return "Racing wheel controller";
+        case XINPUT_DEVSUBTYPE_ARCADE_STICK:
+            return "Arcade stick controller";
+        case XINPUT_DEVSUBTYPE_FLIGHT_STICK:
+            return "Flight stick controller";
+        case XINPUT_DEVSUBTYPE_DANCE_PAD:
+            return "Dance pad controller";
+        case XINPUT_DEVSUBTYPE_GUITAR:
+            return "Guitar controller";
+        case XINPUT_DEVSUBTYPE_GUITAR_ALTERNATE:
+            return "Guitar controller, Alternate";
+        case XINPUT_DEVSUBTYPE_GUITAR_BASS:
+            return "Guitar controller, Bass";
+        case XINPUT_DEVSUBTYPE_DRUM_KIT:
+            return "Drum controller";
+        case XINPUT_DEVSUBTYPE_ARCADE_PAD:
+            return "Arcade pad controller";
+    }
+}
+
+/* Function to perform the mapping from device index to the instance id for this index */
+SDL_JoystickID SDL_SYS_GetInstanceIdOfDeviceIndex(int device_index)
+{
+    return device_index;
+}
+
+/* Function to open a joystick for use.
+   The joystick to open is specified by the index field of the joystick.
+   This should fill the nbuttons and naxes fields of the joystick structure.
+   It returns 0, or -1 if there is an error.
+ */
+int
+SDL_SYS_JoystickOpen(SDL_Joystick * joystick, int device_index)
+{
+    XINPUT_CAPABILITIES deviceCaps;
+
+    if (SDL_XInput_GetDeviceCapabilities(device_index, &deviceCaps) != 0) {
+        /* Uh oh.  Device capabilities couldn't be retrieved.  Return to the
+           caller.  SDL_SetError() has already been invoked (with relevant
+           information).
+         */
+        return -1;
+    }
+
+    /* For now, only game pads are supported.  If the device is something other
+       than that, return an error to the caller.
+     */
+    if (deviceCaps.Type != XINPUT_DEVTYPE_GAMEPAD) {
+        return SDL_SetError("a device is connected (at joystick index, %d), but it is of an unknown device type (deviceCaps.Flags=%ul)",
+            device_index, (unsigned int)deviceCaps.Flags);
+    }
+
+    /* Create the joystick data structure */
+    joystick->instance_id = device_index;
+    joystick->hwdata = &g_XInputData[device_index];
+
+    // 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;
+
+    /* We're done! */
+    return (0);
+}
+
+/* Function to determine is this joystick is attached to the system right now */
+SDL_bool SDL_SYS_JoystickAttached(SDL_Joystick *joystick)
+{
+    return joystick->hwdata->isDeviceConnected;
+}
+
+/* Function to return > 0 if a bit array of buttons differs after applying a mask
+*/
+static int ButtonChanged( int ButtonsNow, int ButtonsPrev, int ButtonMask )
+{
+    return ( ButtonsNow & ButtonMask ) != ( ButtonsPrev & ButtonMask );
+}
+
+/* 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.
+ */
+void
+SDL_SYS_JoystickUpdate(SDL_Joystick * joystick)
+{
+    HRESULT result;
+
+    /* Before polling for new data, make note of the old data */
+    XINPUT_STATE prevXInputState = joystick->hwdata->XInputState;
+
+    /* Poll for new data */
+    result = XInputGetState(joystick->hwdata->userIndex, &joystick->hwdata->XInputState);
+    if (result == ERROR_DEVICE_NOT_CONNECTED) {
+        /* TODO, WinRT: set a flag to indicate that a device-removal event
+           needs to be emitted.
+         */
+        //joystick->hwdata->send_remove_event = 1;
+        //joystick->hwdata->removed = 1;
+        joystick->hwdata->isDeviceConnected = SDL_FALSE;
+        return;
+    }
+
+    /* Make sure the device is marked as connected */
+    joystick->hwdata->isDeviceConnected = SDL_TRUE;
+
+    // only fire events if the data changed from last time
+    if ( joystick->hwdata->XInputState.dwPacketNumber != 0 
+        && joystick->hwdata->XInputState.dwPacketNumber != prevXInputState.dwPacketNumber )
+    {
+        XINPUT_STATE *pXInputState = &joystick->hwdata->XInputState;
+        XINPUT_STATE *pXInputStatePrev = &prevXInputState;
+
+        SDL_PrivateJoystickAxis(joystick, 0, (Sint16)pXInputState->Gamepad.sThumbLX );
+        SDL_PrivateJoystickAxis(joystick, 1, (Sint16)(-1*pXInputState->Gamepad.sThumbLY-1) );
+        SDL_PrivateJoystickAxis(joystick, 2, (Sint16)pXInputState->Gamepad.sThumbRX );
+        SDL_PrivateJoystickAxis(joystick, 3, (Sint16)(-1*pXInputState->Gamepad.sThumbRY-1) );
+        SDL_PrivateJoystickAxis(joystick, 4, (Sint16)((int)pXInputState->Gamepad.bLeftTrigger*32767/255) );
+        SDL_PrivateJoystickAxis(joystick, 5, (Sint16)((int)pXInputState->Gamepad.bRightTrigger*32767/255) );
+
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_DPAD_UP ) )
+            SDL_PrivateJoystickButton(joystick, 0, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_UP ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_DPAD_DOWN ) )
+            SDL_PrivateJoystickButton(joystick, 1, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_DOWN ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_DPAD_LEFT ) )
+            SDL_PrivateJoystickButton(joystick, 2, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_LEFT ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_DPAD_RIGHT ) )
+            SDL_PrivateJoystickButton(joystick, 3, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_DPAD_RIGHT ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_START ) )
+            SDL_PrivateJoystickButton(joystick, 4, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_START ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_BACK ) )
+            SDL_PrivateJoystickButton(joystick, 5, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_BACK ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_LEFT_THUMB ) )
+            SDL_PrivateJoystickButton(joystick, 6, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_LEFT_THUMB ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_RIGHT_THUMB ) )
+            SDL_PrivateJoystickButton(joystick, 7, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_RIGHT_THUMB ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_LEFT_SHOULDER ) )
+            SDL_PrivateJoystickButton(joystick, 8, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_LEFT_SHOULDER ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_RIGHT_SHOULDER ) )
+            SDL_PrivateJoystickButton(joystick, 9, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_RIGHT_SHOULDER ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_A ) )
+            SDL_PrivateJoystickButton(joystick, 10, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_A ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_B ) )
+            SDL_PrivateJoystickButton(joystick, 11, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_B ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_X ) )
+            SDL_PrivateJoystickButton(joystick, 12, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_X ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons, XINPUT_GAMEPAD_Y ) )
+            SDL_PrivateJoystickButton(joystick, 13, pXInputState->Gamepad.wButtons & XINPUT_GAMEPAD_Y ? SDL_PRESSED :	SDL_RELEASED );
+        if ( ButtonChanged( pXInputState->Gamepad.wButtons, pXInputStatePrev->Gamepad.wButtons,  0x400 ) )
+            SDL_PrivateJoystickButton(joystick, 14, pXInputState->Gamepad.wButtons & 0x400 ? SDL_PRESSED :	SDL_RELEASED ); // 0x400 is the undocumented code for the guide button
+    }
+}
+
+/* Function to close a joystick after use */
+void
+SDL_SYS_JoystickClose(SDL_Joystick * joystick)
+{
+    /* Clear cached button data on the joystick */
+    SDL_zero(joystick->hwdata->XInputState);
+
+    /* There's need to free 'hwdata', as it's a pointer to a global array.
+       The field will be cleared anyways, just to indicate that it's not
+       currently needed.
+     */
+    joystick->hwdata = NULL;
+}
+
+/* Function to perform any system-specific joystick related cleanup */
+void
+SDL_SYS_JoystickQuit(void)
+{
+    return;
+}
+
+SDL_JoystickGUID SDL_SYS_JoystickGetDeviceGUID( int device_index )
+{
+    SDL_JoystickGUID guid;
+    // the GUID is just the first 16 chars of the name for now
+    const char *name = SDL_SYS_JoystickNameForDeviceIndex( device_index );
+    SDL_zero( guid );
+    SDL_memcpy( &guid, name, SDL_min( sizeof(guid), SDL_strlen( name ) ) );
+    return guid;
+}
+
+
+SDL_JoystickGUID SDL_SYS_JoystickGetGUID(SDL_Joystick * joystick)
+{
+    SDL_JoystickGUID guid;
+    // the GUID is just the first 16 chars of the name for now
+    const char *name = joystick->name;
+    SDL_zero( guid );
+    SDL_memcpy( &guid, name, SDL_min( sizeof(guid), SDL_strlen( name ) ) );
+    return guid;
+}
+
+SDL_bool SDL_SYS_IsXInputDeviceIndex(int device_index)
+{
+    /* The XInput-capable DirectInput joystick backend implements the same
+       function (SDL_SYS_IsXInputDeviceIndex), however in that case, not all
+       joystick devices are XInput devices.  In this case, with the
+       WinRT-enabled XInput-only backend, all "joystick" devices are XInput
+       devices.
+     */
+    return SDL_TRUE;
+}
+
+#endif /* SDL_JOYSTICK_XINPUT */
+
+/* vi: set ts=4 sw=4 expandtab: */