docs/README-winrt.md
author David Ludwig
Tue, 02 Dec 2014 21:18:50 -0500
changeset 9255 c2ef0d8d6da0
parent 9247 eddb899239fe
child 9335 3eb0896ecb91
permissions -rw-r--r--
WinRT: removed SDL_HINT_WINRT_PREF_PATH_ROOT (introduced post-2.0.3 & pre-2.0.4)

A WinRT app's Roaming folder-path can still be retrieved via calls to
SDL_WinRTGetFSPathUTF8() or SDL_WinRTGetFSPathUNICODE(), if need be.
     1 WinRT
     2 =====
     3 
     4 This port allows SDL applications to run on Microsoft's platforms that require
     5 use of "Windows Runtime", aka. "WinRT", APIs.  WinRT apps are currently
     6 full-screen only, and run in what Microsoft sometimes refers to as their
     7 "Modern" (formerly, "Metro"), environment.  For Windows 8.x, Microsoft may also
     8 refer to them as "Windows Store" apps, due to them being distributed,
     9 primarily, via a Microsoft-run online store (of the same name).
    10 
    11 Some of the operating systems that include WinRT, are:
    12 
    13 * Windows 8.x
    14 * Windows RT 8.x (aka. Windows 8.x for ARM processors)
    15 * Windows Phone 8.x
    16 
    17 
    18 Requirements
    19 ------------
    20 
    21 * Microsoft Visual C++ (aka Visual Studio), either 2013 or 2012 versions
    22   - Free, "Community" or "Express" editions may be used, so long as they
    23     include  support for either "Windows Store" or "Windows Phone" apps.
    24     "Express" versions marked as supporting "Windows Desktop" development
    25     typically do not include support for creating WinRT apps, to note.
    26     (The "Community" edition of Visual C++ 2013 does, however, support both
    27     desktop/Win32 and WinRT development).
    28   - Visual C++ 2012 can only build apps that target versions 8.0 of Windows,
    29     or  Windows Phone.  8.0-targetted apps will run on devices running 8.1
    30     editions of Windows, however they will not be able to take advantage of
    31     8.1-specific features.
    32   - Visual C++ 2013 cannot create app projects that target Windows 8.0.
    33     Visual C++ 2013 Update 4, can create app projects for Windows Phone 8.0,
    34     Windows Phone 8.1, and Windows 8.1, but not Windows 8.0.  An optional
    35     Visual Studio add-in, "Tools for Maintaining Store apps for Windows 8",
    36     allows Visual C++ 2013 to load and build Windows 8.0 projects that were
    37     created with Visual C++ 2012, so long as Visual C++ 2012 is installed
    38     on the same machine.  More details on targeting different versions of
    39     Windows can found at the following web pages:
    40       - [Develop apps by using Visual Studio 2013](http://msdn.microsoft.com/en-us/library/windows/apps/br211384.aspx)
    41       - [To add the Tools for Maintaining Store apps for Windows 8](http://msdn.microsoft.com/en-us/library/windows/apps/dn263114.aspx#AddMaintenanceTools)
    42 * A valid Microsoft account - This requirement is not imposed by SDL, but
    43   rather by Microsoft's Visual C++ toolchain.  This is required to launch or 
    44   debug apps.
    45 
    46 
    47 Status
    48 ------
    49 
    50 Here is a rough list of what works, and what doens't:
    51 
    52 * What works:
    53   * compilation via Visual C++ 2012 and 2013
    54   * compile-time platform detection for SDL programs.  The C/C++ #define,
    55     `__WINRT__`, will be set to 1 (by SDL) when compiling for WinRT.
    56   * GPU-accelerated 2D rendering, via SDL_Renderer.
    57   * software rendering, via either SDL_Surface (optionally in conjunction with
    58     SDL_GetWindowSurface() and SDL_UpdateWindowSurface()) or via the
    59     SDL_Renderer APIs
    60   * threads.  Significant chunks of Win32's threading APIs are not available in
    61     WinRT.  A new, SDL threading backend was built using C++11's threading APIs
    62     (std::thread, std::mutex, std::condition_variable, etc.), which C or C++
    63     programs alike can access via SDL's threading APIs.  Support for thread
    64     priorities is not, however, currently available, due to restrictions in
    65     WinRT's own API set.
    66   * timers (via SDL_GetTicks(), SDL_AddTimer(), SDL_GetPerformanceCounter(),
    67     SDL_GetPerformanceFrequency(), etc.)
    68   * file I/O via SDL_RWops
    69   * mouse input  (unsupported on Windows Phone)
    70   * audio, via a modified version of SDL's XAudio2 backend
    71   * .DLL file loading.  Libraries must be packaged inside applications.  Loading
    72     anything outside of the app is not supported.
    73   * system path retrieval via SDL's filesystem APIs
    74   * game controllers.  Support is provided via the SDL_Joystick and
    75     SDL_GameController APIs, and is backed by Microsoft's XInput API.
    76   * multi-touch input
    77   * app events.  SDL_APP_WILLENTER* and SDL_APP_DIDENTER* events get sent out as
    78     appropriate.
    79   * window events.  SDL_WINDOWEVENT_MINIMIZED and SDL_WINDOWEVENT_RESTORED are
    80     sent out on app suspend and resume, respectively.  SDL_WINDOWEVENT_SHOWN and
    81     SDL_WINDOWEVENT_HIDDEN are also sent, but not necessarily on app suspend or
    82     resume, as WinRT treats these two concepts differently..
    83   * using Direct3D 11.x APIs outside of SDL.  Non-XAML / Direct3D-only apps can
    84     choose to render content directly via Direct3D, using SDL to manage the
    85     internal WinRT window, as well as input and audio.  (Use
    86     SDL_GetWindowWMInfo() to get the WinRT 'CoreWindow', and pass it into
    87     IDXGIFactory2::CreateSwapChainForCoreWindow() as appropriate.)
    88 
    89 * What partially works:
    90   * keyboard input.  Most of WinRT's documented virtual keys are supported, as
    91     well as many keys with documented hardware scancodes.
    92   * OpenGL.  Experimental support for OpenGL ES 2 is available via the ANGLE
    93     project, using either MS Open Technologies' repository, at 
    94     https://github.com/msopentech/angle (both the "winrt" and "future-dev"
    95     branches are supported), or the official ANGLE repository, at
    96     https://chromium.googlesource.com/angle/angle
    97   * SDLmain.  WinRT uses a different signature for each app's main() function.
    98     SDL-based apps that use this port must compile in SDL_winrt_main_NonXAML.cpp
    99     (in `SDL\src\main\winrt\`) directly in order for their C-style main()
   100     functions to be called.
   101   * XAML interoperability.  This feature is currently experimental (there are
   102     **many** known bugs in this, at present!), preliminary, and only for
   103     Windows 8.x/RT at the moment.  Windows Phone + XAML support is still
   104     pending.
   105 
   106 * What doesn't work:
   107   * compilation with anything other than Visual C++ 2012 or 2013
   108   * programmatically-created custom cursors.  These don't appear to be supported
   109     by WinRT.  Different OS-provided cursors can, however, be created via
   110     SDL_CreateSystemCursor() (unsupported on Windows Phone)
   111   * SDL_WarpMouseInWindow() or SDL_WarpMouseGlobal().  This are not currently
   112     supported by WinRT itself.
   113   * joysticks and game controllers that aren't supported by Microsoft's XInput
   114     API.
   115   * probably anything else that's not listed as supported
   116 
   117 
   118 
   119 Upgrade Notes
   120 -------------
   121 
   122 #### SDL_GetPrefPath() usage when upgrading WinRT apps from SDL 2.0.3
   123 
   124 SDL 2.0.4 fixes two bugs found in the WinRT version of SDL_GetPrefPath().
   125 The fixes may affect older, SDL 2.0.3-based apps' save data.  Please note
   126 that these changes only apply to SDL-based WinRT apps, and not to apps for
   127 any other platform.
   128 
   129 1. SDL_GetPrefPath() would return an invalid path, one in which the path's
   130    directory had not been created.  Attempts to create files there
   131    (via fopen(), for example), would fail, unless that directory was
   132    explicitly created beforehand.
   133 
   134 2. SDL_GetPrefPath(), for non-WinPhone-based apps, would return a path inside
   135    a WinRT 'Roaming' folder, the contents of which get automatically
   136    synchronized across multiple devices.  This process can occur while an
   137    application runs, and can cause existing save-data to be overwritten
   138    at unexpected times, with data from other devices.  (Windows Phone apps
   139    written with SDL 2.0.3 did not utilize a Roaming folder, due to API
   140    restrictions in Windows Phone 8.0).
   141 
   142 
   143 SDL_GetPrefPath(), starting with SDL 2.0.4, addresses these by:
   144 
   145 1. making sure that SDL_GetPrefPath() returns a directory in which data
   146    can be written to immediately, without first needing to create directories.
   147 
   148 2. basing SDL_GetPrefPath() off of a different, non-Roaming folder, the
   149    contents of which do not automatically get synchronized across devices
   150    (and which require less work to use safely, in terms of data integrity).
   151 
   152 Apps that wish to get their Roaming folder's path can do so either by using
   153 SDL_WinRTGetFSPathUTF8(), SDL_WinRTGetFSPathUNICODE() (which returns a
   154 UCS-2/wide-char string), or directly through the WinRT class,
   155 Windows.Storage.ApplicationData.
   156 
   157 
   158 
   159 Setup, High-Level Steps
   160 -----------------------
   161 
   162 The steps for setting up a project for an SDL/WinRT app looks like the
   163 following, at a high-level:
   164 
   165 1. create a new Visual C++ project using Microsoft's template for a,
   166    "Direct3D App".
   167 2. remove most of the files from the project.
   168 3. make your app's project directly reference SDL/WinRT's own Visual C++
   169    project file, via use of Visual C++'s "References" dialog.  This will setup
   170    the linker, and will copy SDL's .dll files to your app's final output.
   171 4. adjust your app's build settings, at minimum, telling it where to find SDL's
   172    header files.
   173 5. add a file that contains a WinRT-appropriate main function.
   174 6. add SDL-specific app code.
   175 7. build and run your app.
   176 
   177 
   178 Setup, Detailed Steps
   179 ---------------------
   180 
   181 ### 1. Create a new project ###
   182 
   183 Create a new project using one of Visual C++'s templates for a plain, non-XAML,
   184 "Direct3D App" (XAML support for SDL/WinRT is not yet ready for use).  If you
   185 don't see one of these templates, in Visual C++'s 'New Project' dialog, try
   186 using the textbox titled, 'Search Installed Templates' to look for one.
   187 
   188 
   189 ### 2. Remove unneeded files from the project ###
   190 
   191 In the new project, delete any file that has one of the following extensions:
   192 
   193 - .cpp
   194 - .h
   195 - .hlsl
   196 
   197 When you are done, you should be left with a few files, each of which will be a
   198 necessary part of your app's project.  These files will consist of:
   199 
   200 - an .appxmanifest file, which contains metadata on your WinRT app.  This is
   201   similar to an Info.plist file on iOS, or an AndroidManifest.xml on Android.
   202 - a few .png files, one of which is a splash screen (displayed when your app
   203   launches), others are app icons.
   204 - a .pfx file, used for code signing purposes.
   205 
   206 
   207 ### 3. Add references to SDL's project files ###
   208 
   209 SDL/WinRT can be built in multiple variations, spanning across three different
   210 CPU architectures (x86, x64, and ARM) and two different configurations
   211 (Debug and Release).  WinRT and Visual C++ do not currently provide a means
   212 for combining multiple variations of one library into a single file.
   213 Furthermore, it does not provide an easy means for copying pre-built .dll files
   214 into your app's final output (via Post-Build steps, for example).  It does,
   215 however, provide a system whereby an app can reference the MSVC projects of
   216 libraries such that, when the app is built:
   217 
   218 1. each library gets built for the appropriate CPU architecture(s) and WinRT
   219    platform(s).
   220 2. each library's output, such as .dll files, get copied to the app's build 
   221    output.
   222 
   223 To set this up for SDL/WinRT, you'll need to run through the following steps:
   224 
   225 1. open up the Solution Explorer inside Visual C++ (under the "View" menu, then
   226    "Solution Explorer")
   227 2. right click on your app's solution.
   228 3. navigate to "Add", then to "Existing Project..."
   229 4. find SDL/WinRT's Visual C++ project file and open it.  Different project
   230    files exist for different WinRT platforms.  All of them are in SDL's
   231    source distribution, in the following directories:
   232     * `VisualC-WinRT/WinPhone80_VS2012/` - for Windows Phone 8.0 apps
   233     * `VisualC-WinRT/WinPhone81_VS2013/` - for Windows Phone 8.1 apps
   234     * `VisualC-WinRT/WinRT80_VS2012/` - for Windows 8.0 apps
   235     * `VisualC-WinRT/WinRT81_VS2013/` - for Windows 8.1 apps
   236 5. once the project has been added, right-click on your app's project and
   237    select, "References..."
   238 6. click on the button titled, "Add New Reference..."
   239 7. check the box next to SDL
   240 8. click OK to close the dialog
   241 9. SDL will now show up in the list of references.  Click OK to close that
   242    dialog.
   243 
   244 Your project is now linked to SDL's project, insofar that when the app is
   245 built, SDL will be built as well, with its build output getting included with
   246 your app.
   247 
   248 
   249 ### 4. Adjust Your App's Build Settings ###
   250 
   251 Some build settings need to be changed in your app's project.  This guide will
   252 outline the following:
   253 
   254 - making sure that the compiler knows where to find SDL's header files
   255 - **Optional for C++, but NECESSARY for compiling C code:** telling the
   256   compiler not to use Microsoft's C++ extensions for WinRT development.
   257 - **Optional:** telling the compiler not generate errors due to missing
   258   precompiled header files.
   259 
   260 To change these settings:
   261 
   262 1. right-click on the project
   263 2. choose "Properties"
   264 3. in the drop-down box next to "Configuration", choose, "All Configurations"
   265 4. in the drop-down box next to "Platform", choose, "All Platforms"
   266 5. in the left-hand list, expand the "C/C++" section
   267 6. select "General"
   268 7. edit the "Additional Include Directories" setting, and add a path to SDL's
   269    "include" directory
   270 8. **Optional: to enable compilation of C code:** change the setting for
   271    "Consume Windows Runtime Extension" from "Yes (/ZW)" to "No".  If you're 
   272    working with a completely C++ based project, this step can usually be 
   273    omitted.
   274 9. **Optional: to disable precompiled headers (which can produce 
   275    'stdafx.h'-related build errors, if setup incorrectly:** in the left-hand 
   276    list, select "Precompiled Headers", then change the setting for "Precompiled 
   277    Header" from "Use (/Yu)" to "Not Using Precompiled Headers".
   278 10. close the dialog, saving settings, by clicking the "OK" button
   279 
   280 
   281 ### 5. Add a WinRT-appropriate main function to the app. ###
   282 
   283 C/C++-based WinRT apps do contain a `main` function that the OS will invoke when 
   284 the app starts launching. The parameters of WinRT main functions are different 
   285 than those found on other platforms, Win32 included.  SDL/WinRT provides a 
   286 platform-appropriate main function that will perform these actions, setup key 
   287 portions of the app, then invoke a classic, C/C++-style main function (that take 
   288 in "argc" and "argv" parameters).  The code for this file is contained inside 
   289 SDL's source distribution, under `src/main/winrt/SDL_winrt_main_NonXAML.cpp`.  
   290 You'll need to add this file, or a copy of it, to your app's project, and make 
   291 sure it gets compiled using a Microsoft-specific set of C++ extensions called 
   292 C++/CX.
   293 
   294 **NOTE: C++/CX compilation is currently required in at least one file of your 
   295 app's project.  This is to make sure that Visual C++'s linker builds a 'Windows 
   296 Metadata' file (.winmd) for your app.  Not doing so can lead to build errors.**
   297 
   298 To include `SDL_winrt_main_NonXAML.cpp`:
   299 
   300 1. right-click on your project (again, in Visual C++'s Solution Explorer), 
   301    navigate to "Add", then choose "Existing Item...".
   302 2. open `SDL_winrt_main_NonXAML.cpp`, which is found inside SDL's source 
   303    distribution, under `src/main/winrt/`.  Make sure that the open-file dialog 
   304    closes, either by double-clicking on the file, or single-clicking on it and 
   305    then clicking Add.
   306 3. right-click on the file (as listed in your project), then click on 
   307    "Properties...".
   308 4. in the drop-down box next to "Configuration", choose, "All Configurations"
   309 5. in the drop-down box next to "Platform", choose, "All Platforms"
   310 6. in the left-hand list, click on "C/C++"
   311 7. change the setting for "Consume Windows Runtime Extension" to "Yes (/ZW)".
   312 8. click the OK button.  This will close the dialog.
   313 
   314 
   315 ### 6. Add app code and assets ###
   316 
   317 At this point, you can add in SDL-specific source code.  Be sure to include a 
   318 C-style main function (ie: `int main(int argc, char *argv[])`).  From there you 
   319 should be able to create a single `SDL_Window` (WinRT apps can only have one 
   320 window, at present), as well as an `SDL_Renderer`.  Direct3D will be used to 
   321 draw content.  Events are received via SDL's usual event functions 
   322 (`SDL_PollEvent`, etc.)  If you have a set of existing source files and assets, 
   323 you can start adding them to the project now.  If not, or if you would like to 
   324 make sure that you're setup correctly, some short and simple sample code is 
   325 provided below.
   326 
   327 
   328 #### 6.A. ... when creating a new app ####
   329 
   330 If you are creating a new app (rather than porting an existing SDL-based app), 
   331 or if you would just like a simple app to test SDL/WinRT with before trying to 
   332 get existing code working, some working SDL/WinRT code is provided below.  To 
   333 set this up:
   334 
   335 1. right click on your app's project
   336 2. select Add, then New Item.  An "Add New Item" dialog will show up.
   337 3. from the left-hand list, choose "Visual C++"
   338 4. from the middle/main list, choose "C++ File (.cpp)"
   339 5. near the bottom of the dialog, next to "Name:", type in a name for your 
   340 source file, such as, "main.cpp".
   341 6. click on the Add button.  This will close the dialog, add the new file to 
   342 your project, and open the file in Visual C++'s text editor.
   343 7. Copy and paste the following code into the new file, then save it.
   344 
   345 
   346     #include <SDL.h>
   347     
   348     int main(int argc, char **argv)
   349     {
   350         SDL_DisplayMode mode;
   351         SDL_Window * window = NULL;
   352         SDL_Renderer * renderer = NULL;
   353         SDL_Event evt;
   354     
   355         if (SDL_Init(SDL_INIT_VIDEO) != 0) {
   356             return 1;
   357         }
   358     
   359         if (SDL_GetCurrentDisplayMode(0, &mode) != 0) {
   360             return 1;
   361         }
   362     
   363         if (SDL_CreateWindowAndRenderer(mode.w, mode.h, SDL_WINDOW_FULLSCREEN, &window, &renderer) != 0) {
   364             return 1;
   365         }
   366     
   367         while (1) {
   368             while (SDL_PollEvent(&evt)) {
   369             }
   370     
   371             SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255);
   372             SDL_RenderClear(renderer);
   373             SDL_RenderPresent(renderer);
   374         }
   375     }
   376 
   377 
   378 #### 6.B. Adding code and assets ####
   379 
   380 If you have existing code and assets that you'd like to add, you should be able 
   381 to add them now.  The process for adding a set of files is as such.
   382 
   383 1. right click on the app's project
   384 2. select Add, then click on "New Item..."
   385 3. open any source, header, or asset files as appropriate.  Support for C and 
   386 C++ is available.
   387 
   388 Do note that WinRT only supports a subset of the APIs that are available to 
   389 Win32-based apps.  Many portions of the Win32 API and the C runtime are not 
   390 available.
   391 
   392 A list of unsupported C APIs can be found at 
   393 <http://msdn.microsoft.com/en-us/library/windows/apps/jj606124.aspx>
   394 
   395 General information on using the C runtime in WinRT can be found at 
   396 <http://msdn.microsoft.com/en-us/LIBRARY/hh972425(v=vs.110).aspx>
   397 
   398 A list of supported Win32 APIs for Windows 8/RT apps can be found at 
   399 <http://msdn.microsoft.com/en-us/library/windows/apps/br205757.aspx>.  To note, 
   400 the list of supported Win32 APIs for Windows Phone 8 development is different.  
   401 That list can be found at 
   402 <http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj662956(v=vs.105).aspx>
   403 
   404 
   405 ### 7. Build and run your app ###
   406 
   407 Your app project should now be setup, and you should be ready to build your app.  
   408 To run it on the local machine, open the Debug menu and choose "Start 
   409 Debugging".  This will build your app, then run your app full-screen.  To switch 
   410 out of your app, press the Windows key.  Alternatively, you can choose to run 
   411 your app in a window.  To do this, before building and running your app, find 
   412 the drop-down menu in Visual C++'s toolbar that says, "Local Machine".  Expand 
   413 this by clicking on the arrow on the right side of the list, then click on 
   414 Simulator.  Once you do that, any time you build and run the app, the app will 
   415 launch in window, rather than full-screen.
   416 
   417 
   418 #### 7.A. Running apps on ARM-based devices ####
   419 
   420 To build and run the app on ARM-based, "Windows RT" devices, you'll need to:
   421 
   422 - install Microsoft's "Remote Debugger" on the device.  Visual C++ installs and 
   423   debugs ARM-based apps via IP networks.
   424 - change a few options on the development machine, both to make sure it builds 
   425   for ARM (rather than x86 or x64), and to make sure it knows how to find the 
   426   Windows RT device (on the network).
   427 
   428 Microsoft's Remote Debugger can be found at 
   429 <http://msdn.microsoft.com/en-us/library/vstudio/bt727f1t.aspx>.  Please note 
   430 that separate versions of this debugger exist for different versions of Visual 
   431 C++, one for debugging with MSVC 2012, another for debugging with MSVC 2013.
   432 
   433 To setup Visual C++ to launch your app on an ARM device:
   434 
   435 1. make sure the Remote Debugger is running on your ARM device, and that it's on 
   436    the same IP network as your development machine.
   437 2. from Visual C++'s toolbar, find a drop-down menu that says, "Win32".  Click 
   438    it, then change the value to "ARM".
   439 3. make sure Visual C++ knows the hostname or IP address of the ARM device.  To 
   440    do this:
   441     1. open the app project's properties
   442     2. select "Debugging"
   443     3. next to "Machine Name", enter the hostname or IP address of the ARM 
   444        device
   445     4. if, and only if, you've turned off authentication in the Remote Debugger,
   446        then change the setting for "Require Authentication" to No
   447     5. click "OK"
   448 4. build and run the app (from Visual C++).  The first time you do this, a 
   449    prompt will show up on the ARM device, asking for a Microsoft Account.  You 
   450    do, unfortunately, need to log in here, and will need to follow the 
   451    subsequent registration steps in order to launch the app.  After you do so, 
   452    if the app didn't already launch, try relaunching it again from within Visual 
   453    C++.
   454 
   455 
   456 Troubleshooting
   457 ---------------
   458 
   459 #### Build fails with message, "error LNK2038: mismatch detected for 'vccorlib_lib_should_be_specified_before_msvcrt_lib_to_linker'"
   460 
   461 Try adding the following to your linker flags.  In MSVC, this can be done by
   462 right-clicking on the app project, navigating to Configuration Properties ->
   463 Linker -> Command Line, then adding them to the Additional Options
   464 section.
   465 
   466 * For Release builds / MSVC-Configurations, add:
   467 
   468     /nodefaultlib:vccorlib /nodefaultlib:msvcrt vccorlib.lib msvcrt.lib
   469 
   470 * For Debug builds / MSVC-Configurations, add:
   471 
   472     /nodefaultlib:vccorlibd /nodefaultlib:msvcrtd vccorlibd.lib msvcrtd.lib
   473