From 441359bd5a8ca0a09a00fbfe3212197a0a249c9c Mon Sep 17 00:00:00 2001 From: David Ludwig Date: Sat, 14 May 2016 23:29:49 -0400 Subject: [PATCH] WinRT: workaround a possible Windows bug, whereby hiding cursors, disables mouse-moved events This workaround, unfortunately, requires that apps directly link to a set of Win32-style cursor resource files (that contain a transparent cursor image). Copies of suitable resource files are in src/core/winrt/, and should be included directly in an app's MSVC project. A rough explanation of this workaround/hack, and why it's needed (and seemingly can't be done through programmatic means), is in this change's code. --- docs/README-winrt.md | 57 +++++++++------- .../winrt/SDL2-WinRTResource_BlankCursor.cur | Bin 0 -> 326 bytes src/main/winrt/SDL2-WinRTResources.rc | 3 + src/video/winrt/SDL_winrtmouse.cpp | 63 +++++++++++++++++- 4 files changed, 98 insertions(+), 25 deletions(-) create mode 100644 src/main/winrt/SDL2-WinRTResource_BlankCursor.cur create mode 100644 src/main/winrt/SDL2-WinRTResources.rc diff --git a/docs/README-winrt.md b/docs/README-winrt.md index 581406dda..cccbbeaa8 100644 --- a/docs/README-winrt.md +++ b/docs/README-winrt.md @@ -159,7 +159,9 @@ following, at a high-level: the linker, and will copy SDL's .dll files to your app's final output. 4. adjust your app's build settings, at minimum, telling it where to find SDL's header files. -5. add a file that contains a WinRT-appropriate main function. +5. add files that contains a WinRT-appropriate main function, along with some + data to make sure mouse-cursor-hiding (via SDL_ShowCursor(SDL_DISABLE) calls) + work properly. 6. add SDL-specific app code. 7. build and run your app. @@ -267,33 +269,27 @@ To change these settings: 10. close the dialog, saving settings, by clicking the "OK" button -### 5. Add a WinRT-appropriate main function to the app. ### +### 5. Add a WinRT-appropriate main function, and a blank-cursor image, to the app. ### -C/C++-based WinRT apps do contain a `main` function that the OS will invoke when -the app starts launching. The parameters of WinRT main functions are different -than those found on other platforms, Win32 included. SDL/WinRT provides a -platform-appropriate main function that will perform these actions, setup key -portions of the app, then invoke a classic, C/C++-style main function (that take -in "argc" and "argv" parameters). The code for this file is contained inside -SDL's source distribution, under `src/main/winrt/SDL_winrt_main_NonXAML.cpp`. -You'll need to add this file, or a copy of it, to your app's project, and make -sure it gets compiled using a Microsoft-specific set of C++ extensions called -C++/CX. +A few files should be included directly in your app's MSVC project, specifically: +1. a WinRT-appropriate main function (which is different than main() functions on + other platforms) +2. a Win32-style cursor resource, used by SDL_ShowCursor() to hide the mouse cursor + (if and when the app needs to do so). *If this cursor resource is not + included, mouse-position reporting may fail if and when the cursor is + hidden, due to possible bugs/design-oddities in Windows itself.* -**NOTE: C++/CX compilation is currently required in at least one file of your -app's project. This is to make sure that Visual C++'s linker builds a 'Windows -Metadata' file (.winmd) for your app. Not doing so can lead to build errors.** - -To include `SDL_winrt_main_NonXAML.cpp`: +To include these files: 1. right-click on your project (again, in Visual C++'s Solution Explorer), navigate to "Add", then choose "Existing Item...". -2. open `SDL_winrt_main_NonXAML.cpp`, which is found inside SDL's source - distribution, under `src/main/winrt/`. Make sure that the open-file dialog - closes, either by double-clicking on the file, or single-clicking on it and - then clicking Add. -3. right-click on the file (as listed in your project), then click on - "Properties...". +2. navigate to the directory containing SDL's source code, then into its + subdirectory, 'src/main/winrt/'. Select, then add, the following files: + - `SDL_winrt_main_NonXAML.cpp` + - `SDL2-WinRTResources.rc` + - `SDL2-WinRTResource_BlankCursor.cur` +3. right-click on the file `SDL_winrt_main_NonXAML.cpp` (as listed in your + project), then click on "Properties...". 4. in the drop-down box next to "Configuration", choose, "All Configurations" 5. in the drop-down box next to "Platform", choose, "All Platforms" 6. in the left-hand list, click on "C/C++" @@ -301,6 +297,11 @@ To include `SDL_winrt_main_NonXAML.cpp`: 8. click the OK button. This will close the dialog. +**NOTE: C++/CX compilation is currently required in at least one file of your +app's project. This is to make sure that Visual C++'s linker builds a 'Windows +Metadata' file (.winmd) for your app. Not doing so can lead to build errors.** + + ### 6. Add app code and assets ### At this point, you can add in SDL-specific source code. Be sure to include a @@ -465,3 +466,13 @@ section. /nodefaultlib:vccorlibd /nodefaultlib:msvcrtd vccorlibd.lib msvcrtd.lib + +#### Mouse-motion events fail to get sent, or SDL_GetMouseState() fails to return updated values + +This may be caused by a bug in Windows itself, whereby hiding the mouse +cursor can cause mouse-position reporting to fail. + +SDL provides a workaround for this, but it requires that an app links to a +set of Win32-style cursor image-resource files. A copy of suitable resource +files can be found in `src/main/winrt/`. Adding them to an app's Visual C++ +project file should be sufficient to get the app to use them. diff --git a/src/main/winrt/SDL2-WinRTResource_BlankCursor.cur b/src/main/winrt/SDL2-WinRTResource_BlankCursor.cur new file mode 100644 index 0000000000000000000000000000000000000000..c6556b8a72d272dc9b47f2194b05a1bc022f80a7 GIT binary patch literal 326 zcmc(Zu@L|u2m>F6u%@(h1V?jo3_1k4`wy22aEu6KV;Kx!3QcTLd*wWTxvHpS=06&( HA6jz(2=#;* literal 0 HcmV?d00001 diff --git a/src/main/winrt/SDL2-WinRTResources.rc b/src/main/winrt/SDL2-WinRTResources.rc new file mode 100644 index 000000000..ce8549f2d --- /dev/null +++ b/src/main/winrt/SDL2-WinRTResources.rc @@ -0,0 +1,3 @@ +#include "winres.h" +LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US +5000 CURSOR "SDL2-WinRTResource_BlankCursor.cur" diff --git a/src/video/winrt/SDL_winrtmouse.cpp b/src/video/winrt/SDL_winrtmouse.cpp index d3140a4a4..9997d6ea4 100644 --- a/src/video/winrt/SDL_winrtmouse.cpp +++ b/src/video/winrt/SDL_winrtmouse.cpp @@ -26,6 +26,7 @@ * Windows includes: */ #include +#include using namespace Windows::UI::Core; using Windows::UI::Core::CoreCursor; @@ -116,11 +117,69 @@ WINRT_ShowCursor(SDL_Cursor * cursor) return 0; } + CoreWindow ^ coreWindow = CoreWindow::GetForCurrentThread(); if (cursor) { CoreCursor ^* theCursor = (CoreCursor ^*) cursor->driverdata; - CoreWindow::GetForCurrentThread()->PointerCursor = *theCursor; + coreWindow->PointerCursor = *theCursor; } else { - CoreWindow::GetForCurrentThread()->PointerCursor = nullptr; + // HACK ALERT: TL;DR - Hiding the cursor in WinRT/UWP apps is weird, and + // a Win32-style cursor resource file must be directly included in apps, + // otherwise hiding the cursor will cause mouse-motion data to never be + // received. + // + // Here's the lengthy explanation: + // + // There are two ways to hide a cursor in WinRT/UWP apps. + // Both involve setting the WinRT CoreWindow's (which is somewhat analogous + // to a Win32 HWND) 'PointerCursor' property. + // + // The first way to hide a cursor sets PointerCursor to nullptr. This + // is, arguably, the easiest to implement for an app. It does have an + // unfortunate side-effect: it'll prevent mouse-motion events from being + // sent to the app (via CoreWindow). + // + // The second way to hide a cursor sets PointerCursor to a transparent + // cursor. This allows mouse-motion events to be sent to the app, but is + // more difficult to set up, as: + // 1. WinRT/UWP, while providing a few stock cursors, does not provide + // a completely transparent cursor. + // 2. WinRT/UWP allows apps to provide custom-built cursors, but *ONLY* + // if they are linked directly inside the app, via Win32-style + // cursor resource files. APIs to create cursors at runtime are + // not provided to apps, and attempting to link-to or use Win32 + // cursor-creation APIs could cause an app to fail Windows Store + // certification. + // + // SDL can use either means of hiding the cursor. It provides a Win32-style + // set of cursor resource files in its source distribution, inside + // src/main/winrt/. If those files are linked to an SDL-for-WinRT/UWP app + // (by including them in a MSVC project, for example), SDL will attempt to + // use those, if and when the cursor is hidden via SDL APIs. If those + // files are not linked in, SDL will attempt to hide the cursor via the + // 'set PointerCursor to nullptr' means (which, if you recall, causes + // mouse-motion data to NOT be sent to the app!). + // + // Tech notes: + // - SDL's blank cursor resource uses a resource ID of 5000. + // - SDL's cursor resources consist of the following two files: + // - src/main/winrt/SDL2-WinRTResource_BlankCursor.cur -- cursor pixel data + // - src/main/winrt/SDL2-WinRTResources.rc -- declares the cursor resource, and its ID (of 5000) + // + + const unsigned int win32CursorResourceID = 5000; + CoreCursor ^ blankCursor = ref new CoreCursor(CoreCursorType::Custom, win32CursorResourceID); + + // Set 'PointerCursor' to 'blankCursor' in a way that shouldn't throw + // an exception if the app hasn't loaded that resource. + ABI::Windows::UI::Core::ICoreCursor * iblankCursor = reinterpret_cast(blankCursor); + ABI::Windows::UI::Core::ICoreWindow * icoreWindow = reinterpret_cast(coreWindow); + HRESULT hr = icoreWindow->put_PointerCursor(iblankCursor); + if (FAILED(hr)) { + // The app doesn't contain the cursor resource, or some other error + // occurred. Just use the other, but mouse-motion-preventing, means of + // hiding the cursor. + coreWindow->PointerCursor = nullptr; + } } return 0; }