docs/README-winrt.md
author David Ludwig <dludwig@pobox.com>
Wed, 18 Mar 2015 12:03:32 -0400
changeset 9390 afd88e715bd7
parent 9335 3eb0896ecb91
child 9931 0bb3dd1c95f2
permissions -rw-r--r--
WinRT: updated names, and references-to, various ANGLE/WinRT repositories
     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:
    94     * MS Open Technologies' "ms-master" repository, at https://github.com/MSOpenTech/angle
    95       (for use with Windows 8.1+ or Windows Phone 8.1+)
    96     * MS Open Technologies' "angle-win8.0" repository, at https://github.com/MSOpenTech/angle-win8.0
    97       (for Windows 8.0 only!)
    98     * Google's main ANGLE repository, at https://chromium.googlesource.com/angle/angle
    99   * SDLmain.  WinRT uses a different signature for each app's main() function.
   100     SDL-based apps that use this port must compile in SDL_winrt_main_NonXAML.cpp
   101     (in `SDL\src\main\winrt\`) directly in order for their C-style main()
   102     functions to be called.
   103   * XAML interoperability.  This feature is currently experimental (there are
   104     **many** known bugs in this, at present!), preliminary, and only for
   105     Windows 8.x/RT at the moment.  Windows Phone + XAML support is still
   106     pending.
   107 
   108 * What doesn't work:
   109   * compilation with anything other than Visual C++ 2012 or 2013
   110   * programmatically-created custom cursors.  These don't appear to be supported
   111     by WinRT.  Different OS-provided cursors can, however, be created via
   112     SDL_CreateSystemCursor() (unsupported on Windows Phone)
   113   * SDL_WarpMouseInWindow() or SDL_WarpMouseGlobal().  This are not currently
   114     supported by WinRT itself.
   115   * joysticks and game controllers that aren't supported by Microsoft's XInput
   116     API.
   117   * turning off VSync when rendering on Windows Phone.  Attempts to turn VSync
   118     off on Windows Phone result either in Direct3D not drawing anything, or it
   119     forcing VSync back on.  As such, SDL_RENDERER_PRESENTVSYNC will always get
   120     turned-on on Windows Phone.  This limitation is not present in non-Phone
   121     WinRT (such as Windows 8.x), where turning off VSync appears to work.
   122   * probably anything else that's not listed as supported
   123 
   124 
   125 
   126 Upgrade Notes
   127 -------------
   128 
   129 #### SDL_GetPrefPath() usage when upgrading WinRT apps from SDL 2.0.3
   130 
   131 SDL 2.0.4 fixes two bugs found in the WinRT version of SDL_GetPrefPath().
   132 The fixes may affect older, SDL 2.0.3-based apps' save data.  Please note
   133 that these changes only apply to SDL-based WinRT apps, and not to apps for
   134 any other platform.
   135 
   136 1. SDL_GetPrefPath() would return an invalid path, one in which the path's
   137    directory had not been created.  Attempts to create files there
   138    (via fopen(), for example), would fail, unless that directory was
   139    explicitly created beforehand.
   140 
   141 2. SDL_GetPrefPath(), for non-WinPhone-based apps, would return a path inside
   142    a WinRT 'Roaming' folder, the contents of which get automatically
   143    synchronized across multiple devices.  This process can occur while an
   144    application runs, and can cause existing save-data to be overwritten
   145    at unexpected times, with data from other devices.  (Windows Phone apps
   146    written with SDL 2.0.3 did not utilize a Roaming folder, due to API
   147    restrictions in Windows Phone 8.0).
   148 
   149 
   150 SDL_GetPrefPath(), starting with SDL 2.0.4, addresses these by:
   151 
   152 1. making sure that SDL_GetPrefPath() returns a directory in which data
   153    can be written to immediately, without first needing to create directories.
   154 
   155 2. basing SDL_GetPrefPath() off of a different, non-Roaming folder, the
   156    contents of which do not automatically get synchronized across devices
   157    (and which require less work to use safely, in terms of data integrity).
   158 
   159 Apps that wish to get their Roaming folder's path can do so either by using
   160 SDL_WinRTGetFSPathUTF8(), SDL_WinRTGetFSPathUNICODE() (which returns a
   161 UCS-2/wide-char string), or directly through the WinRT class,
   162 Windows.Storage.ApplicationData.
   163 
   164 
   165 
   166 Setup, High-Level Steps
   167 -----------------------
   168 
   169 The steps for setting up a project for an SDL/WinRT app looks like the
   170 following, at a high-level:
   171 
   172 1. create a new Visual C++ project using Microsoft's template for a,
   173    "Direct3D App".
   174 2. remove most of the files from the project.
   175 3. make your app's project directly reference SDL/WinRT's own Visual C++
   176    project file, via use of Visual C++'s "References" dialog.  This will setup
   177    the linker, and will copy SDL's .dll files to your app's final output.
   178 4. adjust your app's build settings, at minimum, telling it where to find SDL's
   179    header files.
   180 5. add a file that contains a WinRT-appropriate main function.
   181 6. add SDL-specific app code.
   182 7. build and run your app.
   183 
   184 
   185 Setup, Detailed Steps
   186 ---------------------
   187 
   188 ### 1. Create a new project ###
   189 
   190 Create a new project using one of Visual C++'s templates for a plain, non-XAML,
   191 "Direct3D App" (XAML support for SDL/WinRT is not yet ready for use).  If you
   192 don't see one of these templates, in Visual C++'s 'New Project' dialog, try
   193 using the textbox titled, 'Search Installed Templates' to look for one.
   194 
   195 
   196 ### 2. Remove unneeded files from the project ###
   197 
   198 In the new project, delete any file that has one of the following extensions:
   199 
   200 - .cpp
   201 - .h
   202 - .hlsl
   203 
   204 When you are done, you should be left with a few files, each of which will be a
   205 necessary part of your app's project.  These files will consist of:
   206 
   207 - an .appxmanifest file, which contains metadata on your WinRT app.  This is
   208   similar to an Info.plist file on iOS, or an AndroidManifest.xml on Android.
   209 - a few .png files, one of which is a splash screen (displayed when your app
   210   launches), others are app icons.
   211 - a .pfx file, used for code signing purposes.
   212 
   213 
   214 ### 3. Add references to SDL's project files ###
   215 
   216 SDL/WinRT can be built in multiple variations, spanning across three different
   217 CPU architectures (x86, x64, and ARM) and two different configurations
   218 (Debug and Release).  WinRT and Visual C++ do not currently provide a means
   219 for combining multiple variations of one library into a single file.
   220 Furthermore, it does not provide an easy means for copying pre-built .dll files
   221 into your app's final output (via Post-Build steps, for example).  It does,
   222 however, provide a system whereby an app can reference the MSVC projects of
   223 libraries such that, when the app is built:
   224 
   225 1. each library gets built for the appropriate CPU architecture(s) and WinRT
   226    platform(s).
   227 2. each library's output, such as .dll files, get copied to the app's build 
   228    output.
   229 
   230 To set this up for SDL/WinRT, you'll need to run through the following steps:
   231 
   232 1. open up the Solution Explorer inside Visual C++ (under the "View" menu, then
   233    "Solution Explorer")
   234 2. right click on your app's solution.
   235 3. navigate to "Add", then to "Existing Project..."
   236 4. find SDL/WinRT's Visual C++ project file and open it.  Different project
   237    files exist for different WinRT platforms.  All of them are in SDL's
   238    source distribution, in the following directories:
   239     * `VisualC-WinRT/WinPhone80_VS2012/` - for Windows Phone 8.0 apps
   240     * `VisualC-WinRT/WinPhone81_VS2013/` - for Windows Phone 8.1 apps
   241     * `VisualC-WinRT/WinRT80_VS2012/` - for Windows 8.0 apps
   242     * `VisualC-WinRT/WinRT81_VS2013/` - for Windows 8.1 apps
   243 5. once the project has been added, right-click on your app's project and
   244    select, "References..."
   245 6. click on the button titled, "Add New Reference..."
   246 7. check the box next to SDL
   247 8. click OK to close the dialog
   248 9. SDL will now show up in the list of references.  Click OK to close that
   249    dialog.
   250 
   251 Your project is now linked to SDL's project, insofar that when the app is
   252 built, SDL will be built as well, with its build output getting included with
   253 your app.
   254 
   255 
   256 ### 4. Adjust Your App's Build Settings ###
   257 
   258 Some build settings need to be changed in your app's project.  This guide will
   259 outline the following:
   260 
   261 - making sure that the compiler knows where to find SDL's header files
   262 - **Optional for C++, but NECESSARY for compiling C code:** telling the
   263   compiler not to use Microsoft's C++ extensions for WinRT development.
   264 - **Optional:** telling the compiler not generate errors due to missing
   265   precompiled header files.
   266 
   267 To change these settings:
   268 
   269 1. right-click on the project
   270 2. choose "Properties"
   271 3. in the drop-down box next to "Configuration", choose, "All Configurations"
   272 4. in the drop-down box next to "Platform", choose, "All Platforms"
   273 5. in the left-hand list, expand the "C/C++" section
   274 6. select "General"
   275 7. edit the "Additional Include Directories" setting, and add a path to SDL's
   276    "include" directory
   277 8. **Optional: to enable compilation of C code:** change the setting for
   278    "Consume Windows Runtime Extension" from "Yes (/ZW)" to "No".  If you're 
   279    working with a completely C++ based project, this step can usually be 
   280    omitted.
   281 9. **Optional: to disable precompiled headers (which can produce 
   282    'stdafx.h'-related build errors, if setup incorrectly:** in the left-hand 
   283    list, select "Precompiled Headers", then change the setting for "Precompiled 
   284    Header" from "Use (/Yu)" to "Not Using Precompiled Headers".
   285 10. close the dialog, saving settings, by clicking the "OK" button
   286 
   287 
   288 ### 5. Add a WinRT-appropriate main function to the app. ###
   289 
   290 C/C++-based WinRT apps do contain a `main` function that the OS will invoke when 
   291 the app starts launching. The parameters of WinRT main functions are different 
   292 than those found on other platforms, Win32 included.  SDL/WinRT provides a 
   293 platform-appropriate main function that will perform these actions, setup key 
   294 portions of the app, then invoke a classic, C/C++-style main function (that take 
   295 in "argc" and "argv" parameters).  The code for this file is contained inside 
   296 SDL's source distribution, under `src/main/winrt/SDL_winrt_main_NonXAML.cpp`.  
   297 You'll need to add this file, or a copy of it, to your app's project, and make 
   298 sure it gets compiled using a Microsoft-specific set of C++ extensions called 
   299 C++/CX.
   300 
   301 **NOTE: C++/CX compilation is currently required in at least one file of your 
   302 app's project.  This is to make sure that Visual C++'s linker builds a 'Windows 
   303 Metadata' file (.winmd) for your app.  Not doing so can lead to build errors.**
   304 
   305 To include `SDL_winrt_main_NonXAML.cpp`:
   306 
   307 1. right-click on your project (again, in Visual C++'s Solution Explorer), 
   308    navigate to "Add", then choose "Existing Item...".
   309 2. open `SDL_winrt_main_NonXAML.cpp`, which is found inside SDL's source 
   310    distribution, under `src/main/winrt/`.  Make sure that the open-file dialog 
   311    closes, either by double-clicking on the file, or single-clicking on it and 
   312    then clicking Add.
   313 3. right-click on the file (as listed in your project), then click on 
   314    "Properties...".
   315 4. in the drop-down box next to "Configuration", choose, "All Configurations"
   316 5. in the drop-down box next to "Platform", choose, "All Platforms"
   317 6. in the left-hand list, click on "C/C++"
   318 7. change the setting for "Consume Windows Runtime Extension" to "Yes (/ZW)".
   319 8. click the OK button.  This will close the dialog.
   320 
   321 
   322 ### 6. Add app code and assets ###
   323 
   324 At this point, you can add in SDL-specific source code.  Be sure to include a 
   325 C-style main function (ie: `int main(int argc, char *argv[])`).  From there you 
   326 should be able to create a single `SDL_Window` (WinRT apps can only have one 
   327 window, at present), as well as an `SDL_Renderer`.  Direct3D will be used to 
   328 draw content.  Events are received via SDL's usual event functions 
   329 (`SDL_PollEvent`, etc.)  If you have a set of existing source files and assets, 
   330 you can start adding them to the project now.  If not, or if you would like to 
   331 make sure that you're setup correctly, some short and simple sample code is 
   332 provided below.
   333 
   334 
   335 #### 6.A. ... when creating a new app ####
   336 
   337 If you are creating a new app (rather than porting an existing SDL-based app), 
   338 or if you would just like a simple app to test SDL/WinRT with before trying to 
   339 get existing code working, some working SDL/WinRT code is provided below.  To 
   340 set this up:
   341 
   342 1. right click on your app's project
   343 2. select Add, then New Item.  An "Add New Item" dialog will show up.
   344 3. from the left-hand list, choose "Visual C++"
   345 4. from the middle/main list, choose "C++ File (.cpp)"
   346 5. near the bottom of the dialog, next to "Name:", type in a name for your 
   347 source file, such as, "main.cpp".
   348 6. click on the Add button.  This will close the dialog, add the new file to 
   349 your project, and open the file in Visual C++'s text editor.
   350 7. Copy and paste the following code into the new file, then save it.
   351 
   352 
   353     #include <SDL.h>
   354     
   355     int main(int argc, char **argv)
   356     {
   357         SDL_DisplayMode mode;
   358         SDL_Window * window = NULL;
   359         SDL_Renderer * renderer = NULL;
   360         SDL_Event evt;
   361     
   362         if (SDL_Init(SDL_INIT_VIDEO) != 0) {
   363             return 1;
   364         }
   365     
   366         if (SDL_GetCurrentDisplayMode(0, &mode) != 0) {
   367             return 1;
   368         }
   369     
   370         if (SDL_CreateWindowAndRenderer(mode.w, mode.h, SDL_WINDOW_FULLSCREEN, &window, &renderer) != 0) {
   371             return 1;
   372         }
   373     
   374         while (1) {
   375             while (SDL_PollEvent(&evt)) {
   376             }
   377     
   378             SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255);
   379             SDL_RenderClear(renderer);
   380             SDL_RenderPresent(renderer);
   381         }
   382     }
   383 
   384 
   385 #### 6.B. Adding code and assets ####
   386 
   387 If you have existing code and assets that you'd like to add, you should be able 
   388 to add them now.  The process for adding a set of files is as such.
   389 
   390 1. right click on the app's project
   391 2. select Add, then click on "New Item..."
   392 3. open any source, header, or asset files as appropriate.  Support for C and 
   393 C++ is available.
   394 
   395 Do note that WinRT only supports a subset of the APIs that are available to 
   396 Win32-based apps.  Many portions of the Win32 API and the C runtime are not 
   397 available.
   398 
   399 A list of unsupported C APIs can be found at 
   400 <http://msdn.microsoft.com/en-us/library/windows/apps/jj606124.aspx>
   401 
   402 General information on using the C runtime in WinRT can be found at 
   403 <http://msdn.microsoft.com/en-us/LIBRARY/hh972425(v=vs.110).aspx>
   404 
   405 A list of supported Win32 APIs for Windows 8/RT apps can be found at 
   406 <http://msdn.microsoft.com/en-us/library/windows/apps/br205757.aspx>.  To note, 
   407 the list of supported Win32 APIs for Windows Phone 8 development is different.  
   408 That list can be found at 
   409 <http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj662956(v=vs.105).aspx>
   410 
   411 
   412 ### 7. Build and run your app ###
   413 
   414 Your app project should now be setup, and you should be ready to build your app.  
   415 To run it on the local machine, open the Debug menu and choose "Start 
   416 Debugging".  This will build your app, then run your app full-screen.  To switch 
   417 out of your app, press the Windows key.  Alternatively, you can choose to run 
   418 your app in a window.  To do this, before building and running your app, find 
   419 the drop-down menu in Visual C++'s toolbar that says, "Local Machine".  Expand 
   420 this by clicking on the arrow on the right side of the list, then click on 
   421 Simulator.  Once you do that, any time you build and run the app, the app will 
   422 launch in window, rather than full-screen.
   423 
   424 
   425 #### 7.A. Running apps on ARM-based devices ####
   426 
   427 To build and run the app on ARM-based, "Windows RT" devices, you'll need to:
   428 
   429 - install Microsoft's "Remote Debugger" on the device.  Visual C++ installs and 
   430   debugs ARM-based apps via IP networks.
   431 - change a few options on the development machine, both to make sure it builds 
   432   for ARM (rather than x86 or x64), and to make sure it knows how to find the 
   433   Windows RT device (on the network).
   434 
   435 Microsoft's Remote Debugger can be found at 
   436 <http://msdn.microsoft.com/en-us/library/vstudio/bt727f1t.aspx>.  Please note 
   437 that separate versions of this debugger exist for different versions of Visual 
   438 C++, one for debugging with MSVC 2012, another for debugging with MSVC 2013.
   439 
   440 To setup Visual C++ to launch your app on an ARM device:
   441 
   442 1. make sure the Remote Debugger is running on your ARM device, and that it's on 
   443    the same IP network as your development machine.
   444 2. from Visual C++'s toolbar, find a drop-down menu that says, "Win32".  Click 
   445    it, then change the value to "ARM".
   446 3. make sure Visual C++ knows the hostname or IP address of the ARM device.  To 
   447    do this:
   448     1. open the app project's properties
   449     2. select "Debugging"
   450     3. next to "Machine Name", enter the hostname or IP address of the ARM 
   451        device
   452     4. if, and only if, you've turned off authentication in the Remote Debugger,
   453        then change the setting for "Require Authentication" to No
   454     5. click "OK"
   455 4. build and run the app (from Visual C++).  The first time you do this, a 
   456    prompt will show up on the ARM device, asking for a Microsoft Account.  You 
   457    do, unfortunately, need to log in here, and will need to follow the 
   458    subsequent registration steps in order to launch the app.  After you do so, 
   459    if the app didn't already launch, try relaunching it again from within Visual 
   460    C++.
   461 
   462 
   463 Troubleshooting
   464 ---------------
   465 
   466 #### Build fails with message, "error LNK2038: mismatch detected for 'vccorlib_lib_should_be_specified_before_msvcrt_lib_to_linker'"
   467 
   468 Try adding the following to your linker flags.  In MSVC, this can be done by
   469 right-clicking on the app project, navigating to Configuration Properties ->
   470 Linker -> Command Line, then adding them to the Additional Options
   471 section.
   472 
   473 * For Release builds / MSVC-Configurations, add:
   474 
   475     /nodefaultlib:vccorlib /nodefaultlib:msvcrt vccorlib.lib msvcrt.lib
   476 
   477 * For Debug builds / MSVC-Configurations, add:
   478 
   479     /nodefaultlib:vccorlibd /nodefaultlib:msvcrtd vccorlibd.lib msvcrtd.lib
   480