author David Ludwig <>
Sat, 29 Nov 2014 10:09:30 -0500
changeset 9247 eddb899239fe
parent 8215 54555ad9342c
child 9619 b94b6d0bff0f
permissions -rw-r--r--
WinRT: bug and data-integrity fixes for SDL_GetPrefPath()

This change does a few things, all with regards to the WinRT implementation of

1. it fixes a bug whereby SDL_GetPrefPath() did not create the directory it
returned. On other SDL platforms, SDL_GetPrefPath() will create separate
directories for its 'org' and 'app' folders. Without this, attempts to create
files in the pref-path would fail, unless those directories were first created
by the app, or by some other library the app used. This change makes sure
that these directories get created, before SDL_GetPrefPath() returns to its

2. it defaults to having SDL_GetPrefPath() return a WinRT 'Local' folder
on all platforms. Previously, for Windows Store apps, it would have used a
different, 'Roaming' folder. Files in Roaming folders can be automatically,
and synchronized across multiple devices by Windows. This synchronization can
happen while the app runs, with new files being copied into a running app's
pref-path. Unless an app is specifically designed to handle this scenario,
there is a chance that save-data could be overwritten in unwanted or
unexpected ways.

The default is now to use a Local folder, which does not get synchronized, and
which is arguably a bit safer to use. Apps that wish to use Roaming folders
can do so by setting SDL_HINT_WINRT_PREF_PATH_ROOT to "roaming", however it
is recommended that one first read Microsoft's documentation for Roaming
files, a link to which is provided in

To preserve older pref-path selection behavior (found in SDL 2.0.3, as well as
many pre-2.0.4 versions of SDL from, which uses a Roaming path
in Windows Store apps, and a Local path in Windows Phone, set

Please note that Roaming paths are not supported on Windows Phone 8.0, due to
limitations in the OS itself. Attempts to use this will fail.
(Windows Phone 8.1 does not have this limitation, however.)

3. It makes SDL_GetPrefPath(), when on Windows Phone 8.0, and when
SDL_HINT_WINRT_PREF_PATH_ROOT is set to "roaming", return NULL, rather than
silently defaulting to a Local path (then switching to a Roaming path if and
when the user upgraded to Windows Phone 8.1).
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2014 Sam Lantinga <>
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    22 /**
    23  *  \file SDL_loadso.h
    24  *
    25  *  System dependent library loading routines
    26  *
    27  *  Some things to keep in mind:
    28  *  \li These functions only work on C function names.  Other languages may
    29  *      have name mangling and intrinsic language support that varies from
    30  *      compiler to compiler.
    31  *  \li Make sure you declare your function pointers with the same calling
    32  *      convention as the actual library function.  Your code will crash
    33  *      mysteriously if you do not do this.
    34  *  \li Avoid namespace collisions.  If you load a symbol from the library,
    35  *      it is not defined whether or not it goes into the global symbol
    36  *      namespace for the application.  If it does and it conflicts with
    37  *      symbols in your code or other shared libraries, you will not get
    38  *      the results you expect. :)
    39  */
    41 #ifndef _SDL_loadso_h
    42 #define _SDL_loadso_h
    44 #include "SDL_stdinc.h"
    45 #include "SDL_error.h"
    47 #include "begin_code.h"
    48 /* Set up for C function definitions, even when using C++ */
    49 #ifdef __cplusplus
    50 extern "C" {
    51 #endif
    53 /**
    54  *  This function dynamically loads a shared object and returns a pointer
    55  *  to the object handle (or NULL if there was an error).
    56  *  The 'sofile' parameter is a system dependent name of the object file.
    57  */
    58 extern DECLSPEC void *SDLCALL SDL_LoadObject(const char *sofile);
    60 /**
    61  *  Given an object handle, this function looks up the address of the
    62  *  named function in the shared object and returns it.  This address
    63  *  is no longer valid after calling SDL_UnloadObject().
    64  */
    65 extern DECLSPEC void *SDLCALL SDL_LoadFunction(void *handle,
    66                                                const char *name);
    68 /**
    69  *  Unload a shared object from memory.
    70  */
    71 extern DECLSPEC void SDLCALL SDL_UnloadObject(void *handle);
    73 /* Ends C function definitions when using C++ */
    74 #ifdef __cplusplus
    75 }
    76 #endif
    77 #include "close_code.h"
    79 #endif /* _SDL_loadso_h */
    81 /* vi: set ts=4 sw=4 expandtab: */