WinRT: added platform-specific APIs to access common, writable folder paths

VisualC/SDL/SDL_VS2012_WinRT.vcxproj

@@ -53,6 +53,14 @@
       <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</CompileAsWinRT>
       <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</CompileAsWinRT>
     </ClCompile>
+    <ClCompile Include="..\..\src\core\windowsrt\SDL_winrtpaths.cpp">
+      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|ARM'">true</CompileAsWinRT>
+      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|ARM'">true</CompileAsWinRT>
+      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">true</CompileAsWinRT>
+      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">true</CompileAsWinRT>
+      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">true</CompileAsWinRT>
+      <CompileAsWinRT Condition="'$(Configuration)|$(Platform)'=='Release|x64'">true</CompileAsWinRT>
+    </ClCompile>
     <ClCompile Include="..\..\src\core\windows\SDL_windows.c" />
     <ClCompile Include="..\..\src\cpuinfo\SDL_cpuinfo.c" />
     <ClCompile Include="..\..\src\events\SDL_clipboardevents.c" />

include/SDL_system.h

@@ -93,6 +93,45 @@ extern DECLSPEC const char * SDLCALL SDL_AndroidGetExternalStoragePath();
 #endif /* __ANDROID__ */
 
 
+/* Platform specific functions for Windows RT */
+#if defined(__WINRT__) && __WINRT__
+
+/* Gets the path to the local app data store.
+   Files and directories that should be limited to the local device can be
+   created in this path.
+
+   This function may be used safely on Windows Phone 8, as opposed to
+   SDL_WinRTGetRoamingFolderPath() and SDL_WinRTGetTemporaryFolderPath(),
+   which do not work on Windows Phone 8 (and will return NULL if called
+   from this platform).
+ */
+extern DECLSPEC const char * SDLCALL SDL_WinRTGetLocalFolderPath();
+
+/* Gets the path to the roaming app data store.
+   Files and directories that should roam to different devices can be
+   created in this path.  Be sure to read Microsoft's documentation on
+   roaming files for more information on how this works, as restrictions
+   do apply.
+
+   Please note that on Windows Phone 8, this function will return NULL,
+   as Windows Phone 8 apps do not have an accessible roaming app data
+   store.
+ */
+extern DECLSPEC const char * SDLCALL SDL_WinRTGetRoamingFolderPath();
+
+/* Gets the path to the temporary app data store.
+   Files and directories may be written here, however they may be deleted
+   by Windows at a future date.
+
+   Please note that on Windows Phone 8, this function will return NULL,
+   as Windows Phone 8 apps do not have an accessible temporary app data
+   store.
+*/
+extern DECLSPEC const char * SDLCALL SDL_WinRTGetTemporaryFolderPath();
+
+#endif /* __WINRT__ */
+
+
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus
 /* *INDENT-OFF* */

src/core/windowsrt/SDL_winrtpaths.cpp

@@ -0,0 +1,45 @@
+/* TODO, WinRT: include copyright info in SDL_winrtpaths.cpp
+   TODO, WinRT: add note to SDL_winrtpaths.cpp mentioning that /ZW must be used when compiling the file
+*/
+
+#include "SDL_config.h"
+
+#ifdef __WINRT__
+
+extern "C" {
+#include "SDL_system.h"
+#include "../windows/SDL_windows.h"
+}
+
+using namespace Windows::Storage;
+
+extern "C" const char * SDL_WinRTGetLocalFolderPath()
+{
+    static const char * path = nullptr;
+    if (!path) {
+        path = WIN_StringToUTF8(ApplicationData::Current->LocalFolder->Path->Data());
+    }
+    return path;
+}
+
+extern "C" const char * SDL_WinRTGetRoamingFolderPath()
+{
+    // TODO, WinRT: make SDL_WinRTGetRoamingFolderPath return NULL on Windows Phone 8
+    static const char * path = nullptr;
+    if (!path) {
+        path = WIN_StringToUTF8(ApplicationData::Current->RoamingFolder->Path->Data());
+    }
+    return path;
+}
+
+extern "C" const char * SDL_WinRTGetTemporaryFolderPath()
+{
+    // TODO, WinRT: make SDL_WinRTGetTemporaryFolderPath return NULL on Windows Phone 8
+    static const char * path = nullptr;
+    if (!path) {
+        path = WIN_StringToUTF8(ApplicationData::Current->TemporaryFolder->Path->Data());
+    }
+    return path;
+}
+
+#endif /* __WINRT__ */