include/SDL_version.h
author David Ludwig <dludwig@pobox.com>
Sat, 29 Nov 2014 10:09:30 -0500
changeset 9247 eddb899239fe
parent 9121 00d99eff96a6
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
SDL_GetPrefPath():

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
caller(s).


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 README-winrt.md.

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 hg.libsdl.org), which uses a Roaming path
in Windows Store apps, and a Local path in Windows Phone, set
SDL_HINT_WINRT_PREF_PATH_ROOT to "old".

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 <slouken@libsdl.org>
     4 
     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.
     8 
     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:
    12 
    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 */
    21 
    22 /**
    23  *  \file SDL_version.h
    24  *
    25  *  This header defines the current SDL version.
    26  */
    27 
    28 #ifndef _SDL_version_h
    29 #define _SDL_version_h
    30 
    31 #include "SDL_stdinc.h"
    32 
    33 #include "begin_code.h"
    34 /* Set up for C function definitions, even when using C++ */
    35 #ifdef __cplusplus
    36 extern "C" {
    37 #endif
    38 
    39 /**
    40  *  \brief Information the version of SDL in use.
    41  *
    42  *  Represents the library's version as three levels: major revision
    43  *  (increments with massive changes, additions, and enhancements),
    44  *  minor revision (increments with backwards-compatible changes to the
    45  *  major revision), and patchlevel (increments with fixes to the minor
    46  *  revision).
    47  *
    48  *  \sa SDL_VERSION
    49  *  \sa SDL_GetVersion
    50  */
    51 typedef struct SDL_version
    52 {
    53     Uint8 major;        /**< major version */
    54     Uint8 minor;        /**< minor version */
    55     Uint8 patch;        /**< update version */
    56 } SDL_version;
    57 
    58 /* Printable format: "%d.%d.%d", MAJOR, MINOR, PATCHLEVEL
    59 */
    60 #define SDL_MAJOR_VERSION   2
    61 #define SDL_MINOR_VERSION   0
    62 #define SDL_PATCHLEVEL      4
    63 
    64 /**
    65  *  \brief Macro to determine SDL version program was compiled against.
    66  *
    67  *  This macro fills in a SDL_version structure with the version of the
    68  *  library you compiled against. This is determined by what header the
    69  *  compiler uses. Note that if you dynamically linked the library, you might
    70  *  have a slightly newer or older version at runtime. That version can be
    71  *  determined with SDL_GetVersion(), which, unlike SDL_VERSION(),
    72  *  is not a macro.
    73  *
    74  *  \param x A pointer to a SDL_version struct to initialize.
    75  *
    76  *  \sa SDL_version
    77  *  \sa SDL_GetVersion
    78  */
    79 #define SDL_VERSION(x)                          \
    80 {                                   \
    81     (x)->major = SDL_MAJOR_VERSION;                 \
    82     (x)->minor = SDL_MINOR_VERSION;                 \
    83     (x)->patch = SDL_PATCHLEVEL;                    \
    84 }
    85 
    86 /**
    87  *  This macro turns the version numbers into a numeric value:
    88  *  \verbatim
    89     (1,2,3) -> (1203)
    90     \endverbatim
    91  *
    92  *  This assumes that there will never be more than 100 patchlevels.
    93  */
    94 #define SDL_VERSIONNUM(X, Y, Z)                     \
    95     ((X)*1000 + (Y)*100 + (Z))
    96 
    97 /**
    98  *  This is the version number macro for the current SDL version.
    99  */
   100 #define SDL_COMPILEDVERSION \
   101     SDL_VERSIONNUM(SDL_MAJOR_VERSION, SDL_MINOR_VERSION, SDL_PATCHLEVEL)
   102 
   103 /**
   104  *  This macro will evaluate to true if compiled with SDL at least X.Y.Z.
   105  */
   106 #define SDL_VERSION_ATLEAST(X, Y, Z) \
   107     (SDL_COMPILEDVERSION >= SDL_VERSIONNUM(X, Y, Z))
   108 
   109 /**
   110  *  \brief Get the version of SDL that is linked against your program.
   111  *
   112  *  If you are linking to SDL dynamically, then it is possible that the
   113  *  current version will be different than the version you compiled against.
   114  *  This function returns the current version, while SDL_VERSION() is a
   115  *  macro that tells you what version you compiled with.
   116  *
   117  *  \code
   118  *  SDL_version compiled;
   119  *  SDL_version linked;
   120  *
   121  *  SDL_VERSION(&compiled);
   122  *  SDL_GetVersion(&linked);
   123  *  printf("We compiled against SDL version %d.%d.%d ...\n",
   124  *         compiled.major, compiled.minor, compiled.patch);
   125  *  printf("But we linked against SDL version %d.%d.%d.\n",
   126  *         linked.major, linked.minor, linked.patch);
   127  *  \endcode
   128  *
   129  *  This function may be called safely at any time, even before SDL_Init().
   130  *
   131  *  \sa SDL_VERSION
   132  */
   133 extern DECLSPEC void SDLCALL SDL_GetVersion(SDL_version * ver);
   134 
   135 /**
   136  *  \brief Get the code revision of SDL that is linked against your program.
   137  *
   138  *  Returns an arbitrary string (a hash value) uniquely identifying the
   139  *  exact revision of the SDL library in use, and is only useful in comparing
   140  *  against other revisions. It is NOT an incrementing number.
   141  */
   142 extern DECLSPEC const char *SDLCALL SDL_GetRevision(void);
   143 
   144 /**
   145  *  \brief Get the revision number of SDL that is linked against your program.
   146  *
   147  *  Returns a number uniquely identifying the exact revision of the SDL
   148  *  library in use. It is an incrementing number based on commits to
   149  *  hg.libsdl.org.
   150  */
   151 extern DECLSPEC int SDLCALL SDL_GetRevisionNumber(void);
   152 
   153 
   154 /* Ends C function definitions when using C++ */
   155 #ifdef __cplusplus
   156 }
   157 #endif
   158 #include "close_code.h"
   159 
   160 #endif /* _SDL_version_h */
   161 
   162 /* vi: set ts=4 sw=4 expandtab: */