SDL  2.0
README-winrt.md
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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. Microsoft may, in some cases,
6 refer to them as either "Windows Store", or for Windows 10, "UWP" apps.
7 
8 Some of the operating systems that include WinRT, are:
9 
10 * Windows 10, via its Universal Windows Platform (UWP) APIs
11 * Windows 8.x
12 * Windows RT 8.x (aka. Windows 8.x for ARM processors)
13 * Windows Phone 8.x
14 
15 
16 Requirements
17 ------------
18 
19 * Microsoft Visual C++ (aka Visual Studio), either 2017, 2015, 2013, or 2012
20  - Free, "Community" or "Express" editions may be used, so long as they
21  include support for either "Windows Store" or "Windows Phone" apps.
22  "Express" versions marked as supporting "Windows Desktop" development
23  typically do not include support for creating WinRT apps, to note.
24  (The "Community" editions of Visual C++ do, however, support both
25  desktop/Win32 and WinRT development).
26  - Visual Studio 2017 can be used, however it is recommended that you install
27  the Visual C++ 2015 build tools. These build tools can be installed
28  using VS 2017's installer. Be sure to also install the workload for
29  "Universal Windows Platform development", its optional component, the
30  "C++ Universal Windows Platform tools", and for UWP / Windows 10
31  development, the "Windows 10 SDK (10.0.10240.0)". Please note that
32  targeting UWP / Windows 10 apps from development machine(s) running
33  earlier versions of Windows, such as Windows 7, is not always supported
34  by Visual Studio, and you may get error(s) when attempting to do so.
35  - Visual C++ 2012 can only build apps that target versions 8.0 of Windows,
36  or Windows Phone. 8.0-targeted apps will run on devices running 8.1
37  editions of Windows, however they will not be able to take advantage of
38  8.1-specific features.
39  - Visual C++ 2013 cannot create app projects that target Windows 8.0.
40  Visual C++ 2013 Update 4, can create app projects for Windows Phone 8.0,
41  Windows Phone 8.1, and Windows 8.1, but not Windows 8.0. An optional
42  Visual Studio add-in, "Tools for Maintaining Store apps for Windows 8",
43  allows Visual C++ 2013 to load and build Windows 8.0 projects that were
44  created with Visual C++ 2012, so long as Visual C++ 2012 is installed
45  on the same machine. More details on targeting different versions of
46  Windows can found at the following web pages:
47  - [Develop apps by using Visual Studio 2013](http://msdn.microsoft.com/en-us/library/windows/apps/br211384.aspx)
48  - [To add the Tools for Maintaining Store apps for Windows 8](http://msdn.microsoft.com/en-us/library/windows/apps/dn263114.aspx#AddMaintenanceTools)
49 * A valid Microsoft account - This requirement is not imposed by SDL, but
50  rather by Microsoft's Visual C++ toolchain. This is required to launch or
51  debug apps.
52 
53 
54 Status
55 ------
56 
57 Here is a rough list of what works, and what doesn't:
58 
59 * What works:
60  * compilation via Visual C++ 2012 through 2015
61  * compile-time platform detection for SDL programs. The C/C++ #define,
62  `__WINRT__`, will be set to 1 (by SDL) when compiling for WinRT.
63  * GPU-accelerated 2D rendering, via SDL_Renderer.
64  * OpenGL ES 2, via the ANGLE library (included separately from SDL)
65  * software rendering, via either SDL_Surface (optionally in conjunction with
66  SDL_GetWindowSurface() and SDL_UpdateWindowSurface()) or via the
67  SDL_Renderer APIs
68  * threads
69  * timers (via SDL_GetTicks(), SDL_AddTimer(), SDL_GetPerformanceCounter(),
70  SDL_GetPerformanceFrequency(), etc.)
71  * file I/O via SDL_RWops
72  * mouse input (unsupported on Windows Phone)
73  * audio, via SDL's WASAPI backend (if you want to record, your app must
74  have "Microphone" capabilities enabled in its manifest, and the user must
75  not have blocked access. Otherwise, capture devices will fail to work,
76  presenting as a device disconnect shortly after opening it.)
77  * .DLL file loading. Libraries *MUST* be packaged inside applications. Loading
78  anything outside of the app is not supported.
79  * system path retrieval via SDL's filesystem APIs
80  * game controllers. Support is provided via the SDL_Joystick and
81  SDL_GameController APIs, and is backed by Microsoft's XInput API. Please
82  note, however, that Windows limits game-controller support in UWP apps to,
83  "Xbox compatible controllers" (many controllers that work in Win32 apps,
84  do not work in UWP, due to restrictions in UWP itself.)
85  * multi-touch input
86  * app events. SDL_APP_WILLENTER* and SDL_APP_DIDENTER* events get sent out as
87  appropriate.
88  * window events
89  * using Direct3D 11.x APIs outside of SDL. Non-XAML / Direct3D-only apps can
90  choose to render content directly via Direct3D, using SDL to manage the
91  internal WinRT window, as well as input and audio. (Use
92  SDL_GetWindowWMInfo() to get the WinRT 'CoreWindow', and pass it into
93  IDXGIFactory2::CreateSwapChainForCoreWindow() as appropriate.)
94 
95 * What partially works:
96  * keyboard input. Most of WinRT's documented virtual keys are supported, as
97  well as many keys with documented hardware scancodes. Converting
98  SDL_Scancodes to or from SDL_Keycodes may not work, due to missing APIs
99  (MapVirtualKey()) in Microsoft's Windows Store / UWP APIs.
100  * SDLmain. WinRT uses a different signature for each app's main() function.
101  SDL-based apps that use this port must compile in SDL_winrt_main_NonXAML.cpp
102  (in `SDL\src\main\winrt\`) directly in order for their C-style main()
103  functions to be called.
104 
105 * What doesn't work:
106  * compilation with anything other than Visual C++
107  * programmatically-created custom cursors. These don't appear to be supported
108  by WinRT. Different OS-provided cursors can, however, be created via
109  SDL_CreateSystemCursor() (unsupported on Windows Phone)
110  * SDL_WarpMouseInWindow() or SDL_WarpMouseGlobal(). This are not currently
111  supported by WinRT itself.
112  * joysticks and game controllers that either are not supported by
113  Microsoft's XInput API, or are not supported within UWP apps (many
114  controllers that work in Win32, do not work in UWP, due to restrictions in
115  UWP itself).
116  * turning off VSync when rendering on Windows Phone. Attempts to turn VSync
117  off on Windows Phone result either in Direct3D not drawing anything, or it
118  forcing VSync back on. As such, SDL_RENDERER_PRESENTVSYNC will always get
119  turned-on on Windows Phone. This limitation is not present in non-Phone
120  WinRT (such as Windows 8.x), where turning off VSync appears to work.
121  * probably anything else that's not listed as supported
122 
123 
124 
125 Upgrade Notes
126 -------------
127 
128 #### SDL_GetPrefPath() usage when upgrading WinRT apps from SDL 2.0.3
129 
130 SDL 2.0.4 fixes two bugs found in the WinRT version of SDL_GetPrefPath().
131 The fixes may affect older, SDL 2.0.3-based apps' save data. Please note
132 that these changes only apply to SDL-based WinRT apps, and not to apps for
133 any other platform.
134 
135 1. SDL_GetPrefPath() would return an invalid path, one in which the path's
136  directory had not been created. Attempts to create files there
137  (via fopen(), for example), would fail, unless that directory was
138  explicitly created beforehand.
139 
140 2. SDL_GetPrefPath(), for non-WinPhone-based apps, would return a path inside
141  a WinRT 'Roaming' folder, the contents of which get automatically
142  synchronized across multiple devices. This process can occur while an
143  application runs, and can cause existing save-data to be overwritten
144  at unexpected times, with data from other devices. (Windows Phone apps
145  written with SDL 2.0.3 did not utilize a Roaming folder, due to API
146  restrictions in Windows Phone 8.0).
147 
148 
149 SDL_GetPrefPath(), starting with SDL 2.0.4, addresses these by:
150 
151 1. making sure that SDL_GetPrefPath() returns a directory in which data
152  can be written to immediately, without first needing to create directories.
153 
154 2. basing SDL_GetPrefPath() off of a different, non-Roaming folder, the
155  contents of which do not automatically get synchronized across devices
156  (and which require less work to use safely, in terms of data integrity).
157 
158 Apps that wish to get their Roaming folder's path can do so either by using
159 SDL_WinRTGetFSPathUTF8(), SDL_WinRTGetFSPathUNICODE() (which returns a
160 UCS-2/wide-char string), or directly through the WinRT class,
161 Windows.Storage.ApplicationData.
162 
163 
164 
165 Setup, High-Level Steps
166 -----------------------
167 
168 The steps for setting up a project for an SDL/WinRT app looks like the
169 following, at a high-level:
170 
171 1. create a new Visual C++ project using Microsoft's template for a,
172  "Direct3D App".
173 2. remove most of the files from the project.
174 3. make your app's project directly reference SDL/WinRT's own Visual C++
175  project file, via use of Visual C++'s "References" dialog. This will setup
176  the linker, and will copy SDL's .dll files to your app's final output.
177 4. adjust your app's build settings, at minimum, telling it where to find SDL's
178  header files.
179 5. add files that contains a WinRT-appropriate main function, along with some
180  data to make sure mouse-cursor-hiding (via SDL_ShowCursor(SDL_DISABLE) calls)
181  work properly.
182 6. add SDL-specific app code.
183 7. build and run your app.
184 
185 
186 Setup, Detailed Steps
187 ---------------------
188 
189 ### 1. Create a new project ###
190 
191 Create a new project using one of Visual C++'s templates for a plain, non-XAML,
192 "Direct3D App" (XAML support for SDL/WinRT is not yet ready for use). If you
193 don't see one of these templates, in Visual C++'s 'New Project' dialog, try
194 using the textbox titled, 'Search Installed Templates' to look for one.
195 
196 
197 ### 2. Remove unneeded files from the project ###
198 
199 In the new project, delete any file that has one of the following extensions:
200 
201 - .cpp
202 - .h
203 - .hlsl
204 
205 When you are done, you should be left with a few files, each of which will be a
206 necessary part of your app's project. These files will consist of:
207 
208 - an .appxmanifest file, which contains metadata on your WinRT app. This is
209  similar to an Info.plist file on iOS, or an AndroidManifest.xml on Android.
210 - a few .png files, one of which is a splash screen (displayed when your app
211  launches), others are app icons.
212 - a .pfx file, used for code signing purposes.
213 
214 
215 ### 3. Add references to SDL's project files ###
216 
217 SDL/WinRT can be built in multiple variations, spanning across three different
218 CPU architectures (x86, x64, and ARM) and two different configurations
219 (Debug and Release). WinRT and Visual C++ do not currently provide a means
220 for combining multiple variations of one library into a single file.
221 Furthermore, it does not provide an easy means for copying pre-built .dll files
222 into your app's final output (via Post-Build steps, for example). It does,
223 however, provide a system whereby an app can reference the MSVC projects of
224 libraries such that, when the app is built:
225 
226 1. each library gets built for the appropriate CPU architecture(s) and WinRT
227  platform(s).
228 2. each library's output, such as .dll files, get copied to the app's build
229  output.
230 
231 To set this up for SDL/WinRT, you'll need to run through the following steps:
232 
233 1. open up the Solution Explorer inside Visual C++ (under the "View" menu, then
234  "Solution Explorer")
235 2. right click on your app's solution.
236 3. navigate to "Add", then to "Existing Project..."
237 4. find SDL/WinRT's Visual C++ project file and open it. Different project
238  files exist for different WinRT platforms. All of them are in SDL's
239  source distribution, in the following directories:
240  * `VisualC-WinRT/UWP_VS2015/` - for Windows 10 / UWP apps
241  * `VisualC-WinRT/WinPhone81_VS2013/` - for Windows Phone 8.1 apps
242  * `VisualC-WinRT/WinRT80_VS2012/` - for Windows 8.0 apps
243  * `VisualC-WinRT/WinRT81_VS2013/` - for Windows 8.1 apps
244 5. once the project has been added, right-click on your app's project and
245  select, "References..."
246 6. click on the button titled, "Add New Reference..."
247 7. check the box next to SDL
248 8. click OK to close the dialog
249 9. SDL will now show up in the list of references. Click OK to close that
250  dialog.
251 
252 Your project is now linked to SDL's project, insofar that when the app is
253 built, SDL will be built as well, with its build output getting included with
254 your app.
255 
256 
257 ### 4. Adjust Your App's Build Settings ###
258 
259 Some build settings need to be changed in your app's project. This guide will
260 outline the following:
261 
262 - making sure that the compiler knows where to find SDL's header files
263 - **Optional for C++, but NECESSARY for compiling C code:** telling the
264  compiler not to use Microsoft's C++ extensions for WinRT development.
265 - **Optional:** telling the compiler not generate errors due to missing
266  precompiled header files.
267 
268 To change these settings:
269 
270 1. right-click on the project
271 2. choose "Properties"
272 3. in the drop-down box next to "Configuration", choose, "All Configurations"
273 4. in the drop-down box next to "Platform", choose, "All Platforms"
274 5. in the left-hand list, expand the "C/C++" section
275 6. select "General"
276 7. edit the "Additional Include Directories" setting, and add a path to SDL's
277  "include" directory
278 8. **Optional: to enable compilation of C code:** change the setting for
279  "Consume Windows Runtime Extension" from "Yes (/ZW)" to "No". If you're
280  working with a completely C++ based project, this step can usually be
281  omitted.
282 9. **Optional: to disable precompiled headers (which can produce
283  'stdafx.h'-related build errors, if setup incorrectly:** in the left-hand
284  list, select "Precompiled Headers", then change the setting for "Precompiled
285  Header" from "Use (/Yu)" to "Not Using Precompiled Headers".
286 10. close the dialog, saving settings, by clicking the "OK" button
287 
288 
289 ### 5. Add a WinRT-appropriate main function, and a blank-cursor image, to the app. ###
290 
291 A few files should be included directly in your app's MSVC project, specifically:
292 1. a WinRT-appropriate main function (which is different than main() functions on
293  other platforms)
294 2. a Win32-style cursor resource, used by SDL_ShowCursor() to hide the mouse cursor
295  (if and when the app needs to do so). *If this cursor resource is not
296  included, mouse-position reporting may fail if and when the cursor is
297  hidden, due to possible bugs/design-oddities in Windows itself.*
298 
299 To include these files for C/C++ projects:
300 
301 1. right-click on your project (again, in Visual C++'s Solution Explorer),
302  navigate to "Add", then choose "Existing Item...".
303 2. navigate to the directory containing SDL's source code, then into its
304  subdirectory, 'src/main/winrt/'. Select, then add, the following files:
305  - `SDL_winrt_main_NonXAML.cpp`
306  - `SDL2-WinRTResources.rc`
307  - `SDL2-WinRTResource_BlankCursor.cur`
308 3. right-click on the file `SDL_winrt_main_NonXAML.cpp` (as listed in your
309  project), then click on "Properties...".
310 4. in the drop-down box next to "Configuration", choose, "All Configurations"
311 5. in the drop-down box next to "Platform", choose, "All Platforms"
312 6. in the left-hand list, click on "C/C++"
313 7. change the setting for "Consume Windows Runtime Extension" to "Yes (/ZW)".
314 8. click the OK button. This will close the dialog.
315 
316 **NOTE: C++/CX compilation is currently required in at least one file of your
317 app's project. This is to make sure that Visual C++'s linker builds a 'Windows
318 Metadata' file (.winmd) for your app. Not doing so can lead to build errors.**
319 
320 For non-C++ projects, you will need to call SDL_WinRTRunApp from your language's
321 main function, and generate SDL2-WinRTResources.res manually by using `rc` via
322 the Developer Command Prompt and including it as a <Win32Resource> within the
323 first <PropertyGroup> block in your Visual Studio project file.
324 
325 ### 6. Add app code and assets ###
326 
327 At this point, you can add in SDL-specific source code. Be sure to include a
328 C-style main function (ie: `int main(int argc, char *argv[])`). From there you
329 should be able to create a single `SDL_Window` (WinRT apps can only have one
330 window, at present), as well as an `SDL_Renderer`. Direct3D will be used to
331 draw content. Events are received via SDL's usual event functions
332 (`SDL_PollEvent`, etc.) If you have a set of existing source files and assets,
333 you can start adding them to the project now. If not, or if you would like to
334 make sure that you're setup correctly, some short and simple sample code is
335 provided below.
336 
337 
338 #### 6.A. ... when creating a new app ####
339 
340 If you are creating a new app (rather than porting an existing SDL-based app),
341 or if you would just like a simple app to test SDL/WinRT with before trying to
342 get existing code working, some working SDL/WinRT code is provided below. To
343 set this up:
344 
345 1. right click on your app's project
346 2. select Add, then New Item. An "Add New Item" dialog will show up.
347 3. from the left-hand list, choose "Visual C++"
348 4. from the middle/main list, choose "C++ File (.cpp)"
349 5. near the bottom of the dialog, next to "Name:", type in a name for your
350 source file, such as, "main.cpp".
351 6. click on the Add button. This will close the dialog, add the new file to
352 your project, and open the file in Visual C++'s text editor.
353 7. Copy and paste the following code into the new file, then save it.
354 
355 ```c
356 #include <SDL.h>
357 
358 int main(int argc, char **argv)
359 {
360  SDL_DisplayMode mode;
361  SDL_Window * window = NULL;
362  SDL_Renderer * renderer = NULL;
363  SDL_Event evt;
364  SDL_bool keep_going = SDL_TRUE;
365 
366  if (SDL_Init(SDL_INIT_VIDEO) != 0) {
367  return 1;
368  } else if (SDL_GetCurrentDisplayMode(0, &mode) != 0) {
369  return 1;
370  } else if (SDL_CreateWindowAndRenderer(mode.w, mode.h, SDL_WINDOW_FULLSCREEN, &window, &renderer) != 0) {
371  return 1;
372  }
373 
374  while (keep_going) {
375  while (SDL_PollEvent(&evt)) {
376  if ((evt.type == SDL_KEYDOWN) && (evt.key.keysym.sym == SDLK_ESCAPE)) {
377  keep_going = SDL_FALSE;
378  }
379  }
380 
381  SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255);
382  SDL_RenderClear(renderer);
383  SDL_RenderPresent(renderer);
384  }
385 
386  SDL_Quit();
387  return 0;
388 }
389 ```
390 
391 #### 6.B. Adding code and assets ####
392 
393 If you have existing code and assets that you'd like to add, you should be able
394 to add them now. The process for adding a set of files is as such.
395 
396 1. right click on the app's project
397 2. select Add, then click on "New Item..."
398 3. open any source, header, or asset files as appropriate. Support for C and
399 C++ is available.
400 
401 Do note that WinRT only supports a subset of the APIs that are available to
402 Win32-based apps. Many portions of the Win32 API and the C runtime are not
403 available.
404 
405 A list of unsupported C APIs can be found at
406 <http://msdn.microsoft.com/en-us/library/windows/apps/jj606124.aspx>
407 
408 General information on using the C runtime in WinRT can be found at
409 <https://msdn.microsoft.com/en-us/library/hh972425.aspx>
410 
411 A list of supported Win32 APIs for WinRT apps can be found at
412 <http://msdn.microsoft.com/en-us/library/windows/apps/br205757.aspx>. To note,
413 the list of supported Win32 APIs for Windows Phone 8.0 is different.
414 That list can be found at
415 <http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj662956(v=vs.105).aspx>
416 
417 
418 ### 7. Build and run your app ###
419 
420 Your app project should now be setup, and you should be ready to build your app.
421 To run it on the local machine, open the Debug menu and choose "Start
422 Debugging". This will build your app, then run your app full-screen. To switch
423 out of your app, press the Windows key. Alternatively, you can choose to run
424 your app in a window. To do this, before building and running your app, find
425 the drop-down menu in Visual C++'s toolbar that says, "Local Machine". Expand
426 this by clicking on the arrow on the right side of the list, then click on
427 Simulator. Once you do that, any time you build and run the app, the app will
428 launch in window, rather than full-screen.
429 
430 
431 #### 7.A. Running apps on older, ARM-based, "Windows RT" devices ####
432 
433 **These instructions do not include Windows Phone, despite Windows Phone
434 typically running on ARM processors.** They are specifically for devices
435 that use the "Windows RT" operating system, which was a modified version of
436 Windows 8.x that ran primarily on ARM-based tablet computers.
437 
438 To build and run the app on ARM-based, "Windows RT" devices, you'll need to:
439 
440 - install Microsoft's "Remote Debugger" on the device. Visual C++ installs and
441  debugs ARM-based apps via IP networks.
442 - change a few options on the development machine, both to make sure it builds
443  for ARM (rather than x86 or x64), and to make sure it knows how to find the
444  Windows RT device (on the network).
445 
446 Microsoft's Remote Debugger can be found at
447 <https://msdn.microsoft.com/en-us/library/hh441469.aspx>. Please note
448 that separate versions of this debugger exist for different versions of Visual
449 C++, one each for MSVC 2015, 2013, and 2012.
450 
451 To setup Visual C++ to launch your app on an ARM device:
452 
453 1. make sure the Remote Debugger is running on your ARM device, and that it's on
454  the same IP network as your development machine.
455 2. from Visual C++'s toolbar, find a drop-down menu that says, "Win32". Click
456  it, then change the value to "ARM".
457 3. make sure Visual C++ knows the hostname or IP address of the ARM device. To
458  do this:
459  1. open the app project's properties
460  2. select "Debugging"
461  3. next to "Machine Name", enter the hostname or IP address of the ARM
462  device
463  4. if, and only if, you've turned off authentication in the Remote Debugger,
464  then change the setting for "Require Authentication" to No
465  5. click "OK"
466 4. build and run the app (from Visual C++). The first time you do this, a
467  prompt will show up on the ARM device, asking for a Microsoft Account. You
468  do, unfortunately, need to log in here, and will need to follow the
469  subsequent registration steps in order to launch the app. After you do so,
470  if the app didn't already launch, try relaunching it again from within Visual
471  C++.
472 
473 
474 Troubleshooting
475 ---------------
476 
477 #### Build fails with message, "error LNK2038: mismatch detected for 'vccorlib_lib_should_be_specified_before_msvcrt_lib_to_linker'"
478 
479 Try adding the following to your linker flags. In MSVC, this can be done by
480 right-clicking on the app project, navigating to Configuration Properties ->
481 Linker -> Command Line, then adding them to the Additional Options
482 section.
483 
484 * For Release builds / MSVC-Configurations, add:
485 
486  /nodefaultlib:vccorlib /nodefaultlib:msvcrt vccorlib.lib msvcrt.lib
487 
488 * For Debug builds / MSVC-Configurations, add:
489 
490  /nodefaultlib:vccorlibd /nodefaultlib:msvcrtd vccorlibd.lib msvcrtd.lib
491 
492 
493 #### Mouse-motion events fail to get sent, or SDL_GetMouseState() fails to return updated values
494 
495 This may be caused by a bug in Windows itself, whereby hiding the mouse
496 cursor can cause mouse-position reporting to fail.
497 
498 SDL provides a workaround for this, but it requires that an app links to a
499 set of Win32-style cursor image-resource files. A copy of suitable resource
500 files can be found in `src/main/winrt/`. Adding them to an app's Visual C++
501 project file should be sufficient to get the app to use them.
502 
503 
504 #### SDL's Visual Studio project file fails to open, with message, "The system can't find the file specified."
505 
506 This can be caused for any one of a few reasons, which Visual Studio can
507 report, but won't always do so in an up-front manner.
508 
509 To help determine why this error comes up:
510 
511 1. open a copy of Visual Studio without opening a project file. This can be
512  accomplished via Windows' Start Menu, among other means.
513 2. show Visual Studio's Output window. This can be done by going to VS'
514  menu bar, then to View, and then to Output.
515 3. try opening the SDL project file directly by going to VS' menu bar, then
516  to File, then to Open, then to Project/Solution. When a File-Open dialog
517  appears, open the SDL project (such as the one in SDL's source code, in its
518  directory, VisualC-WinRT/UWP_VS2015/).
519 4. after attempting to open SDL's Visual Studio project file, additional error
520  information will be output to the Output window.
521 
522 If Visual Studio reports (via its Output window) that the project:
523 
524 "could not be loaded because it's missing install components. To fix this launch Visual Studio setup with the following selections:
525 Microsoft.VisualStudio.ComponentGroup.UWP.VC"
526 
527 ... then you will need to re-launch Visual Studio's installer, and make sure that
528 the workflow for "Universal Windows Platform development" is checked, and that its
529 optional component, "C++ Universal Windows Platform tools" is also checked. While
530 you are there, if you are planning on targeting UWP / Windows 10, also make sure
531 that you check the optional component, "Windows 10 SDK (10.0.10240.0)". After
532 making sure these items are checked as-appropriate, install them.
533 
534 Once you install these components, try re-launching Visual Studio, and re-opening
535 the SDL project file. If you still get the error dialog, try using the Output
536 window, again, seeing what Visual Studio says about it.
537 
538 
539 #### Game controllers / joysticks aren't working!
540 
541 Windows only permits certain game controllers and joysticks to work within
542 WinRT / UWP apps. Even if a game controller or joystick works in a Win32
543 app, that device is not guaranteed to work inside a WinRT / UWP app.
544 
545 According to Microsoft, "Xbox compatible controllers" should work inside
546 UWP apps, potentially with more working in the future. This includes, but
547 may not be limited to, Microsoft-made Xbox controllers and USB adapters.
548 (Source: https://social.msdn.microsoft.com/Forums/en-US/9064838b-e8c3-4c18-8a83-19bf0dfe150d/xinput-fails-to-detect-game-controllers?forum=wpdevelop)
549 
550