WinRT: made SDL's inner WinRT CoreWindow be accessible to non-C++/CX code, in theory

include/SDL_syswm.h

@@ -58,6 +58,10 @@ struct SDL_SysWMinfo;
 #include <windows.h>
 #endif
 
+#if defined(SDL_VIDEO_DRIVER_WINRT)
+#include <Unknwn.h>
+#endif
+
 /* This is the structure for custom window manager events */
 #if defined(SDL_VIDEO_DRIVER_X11)
 #if defined(__APPLE__) && defined(__MACH__)
@@ -175,7 +179,7 @@ struct SDL_SysWMinfo
 #if defined(SDL_VIDEO_DRIVER_WINRT)
         struct
         {
-            void * window;          /**< The Windows RT CoreWindow, casted from 'CoreWindow ^*' to 'void *' */
+            IUnknown * window;          /**< The Windows RT CoreWindow */
         } winrt;
 #endif
 #if defined(SDL_VIDEO_DRIVER_X11)

src/render/direct3d11/SDL_render_d3d11.cpp

@@ -23,6 +23,11 @@
 
 #if SDL_VIDEO_RENDER_D3D11 && !SDL_RENDER_DISABLED
 
+#ifdef __WINRT__
+#include <windows.ui.core.h>
+#include <windows.foundation.h>
+#endif
+
 extern "C" {
 #include "../../core/windows/SDL_windows.h"
 //#include "SDL_hints.h"
@@ -562,7 +567,7 @@ D3D11_CreateDeviceResources(SDL_Renderer * renderer)
 
 #ifdef __WINRT__
 
-static CoreWindow ^
+static ABI::Windows::UI::Core::ICoreWindow *
 D3D11_GetCoreWindowFromSDLRenderer(SDL_Renderer * renderer)
 {
     SDL_Window * sdlWindow = renderer->window;
@@ -580,12 +585,16 @@ D3D11_GetCoreWindowFromSDLRenderer(SDL_Renderer * renderer)
         return nullptr;
     }
 
-    CoreWindow ^* coreWindowPointer = (CoreWindow ^*) sdlWindowInfo.info.winrt.window;
-    if ( ! coreWindowPointer ) {
+    if ( ! sdlWindowInfo.info.winrt.window ) {
         return nullptr;
     }
 
-    return *coreWindowPointer;
+    ABI::Windows::UI::Core::ICoreWindow * coreWindow = nullptr;
+    if (FAILED(sdlWindowInfo.info.winrt.window->QueryInterface(&coreWindow))) {
+        return nullptr;
+    }
+
+    return coreWindow;
 }
 
 // Method to convert a length in device-independent pixels (DIPs) to a length in physical pixels.
@@ -604,12 +613,19 @@ D3D11_CreateWindowSizeDependentResources(SDL_Renderer * renderer)
 {
     D3D11_RenderData *data = (D3D11_RenderData *) renderer->driverdata;
     HRESULT result = S_OK;
-    Windows::UI::Core::CoreWindow ^ coreWindow = D3D11_GetCoreWindowFromSDLRenderer(renderer);
+    ABI::Windows::UI::Core::ICoreWindow * coreWindow = D3D11_GetCoreWindowFromSDLRenderer(renderer);
 
     // Store the window bounds so the next time we get a SizeChanged event we can
     // avoid rebuilding everything if the size is identical.
-    data->windowSizeInDIPs.x = coreWindow->Bounds.Width;
-    data->windowSizeInDIPs.y = coreWindow->Bounds.Height;
+    ABI::Windows::Foundation::Rect coreWindowBounds;
+    result = coreWindow->get_Bounds(&coreWindowBounds);
+    if (FAILED(result)) {
+        WIN_SetErrorFromHRESULT(__FUNCTION__", Get Window Bounds", result);
+        return result;
+    }
+
+    data->windowSizeInDIPs.x = coreWindowBounds.Width;
+    data->windowSizeInDIPs.y = coreWindowBounds.Height;
 
     // Calculate the necessary swap chain and render target size in pixels.
     float windowWidth = D3D11_ConvertDipsToPixels(data->windowSizeInDIPs.x);
@@ -685,9 +701,16 @@ D3D11_CreateWindowSizeDependentResources(SDL_Renderer * renderer)
             return result;
         }
 
+        IUnknown * coreWindowAsIUnknown = nullptr;
+        result = coreWindow->QueryInterface(&coreWindowAsIUnknown);
+        if (FAILED(result)) {
+            WIN_SetErrorFromHRESULT(__FUNCTION__ ", CoreWindow to IUnknown", result);
+            return result;
+        }
+
         result = dxgiFactory->CreateSwapChainForCoreWindow(
             data->d3dDevice.Get(),
-            reinterpret_cast<IUnknown*>(coreWindow),
+            coreWindowAsIUnknown,
             &swapChainDesc,
             nullptr, // Allow on all displays.
             &data->swapChain
@@ -776,10 +799,17 @@ D3D11_UpdateForWindowSizeChange(SDL_Renderer * renderer)
 {
     D3D11_RenderData *data = (D3D11_RenderData *) renderer->driverdata;
     HRESULT result = S_OK;
-    Windows::UI::Core::CoreWindow ^ coreWindow = D3D11_GetCoreWindowFromSDLRenderer(renderer);
+    ABI::Windows::UI::Core::ICoreWindow * coreWindow = D3D11_GetCoreWindowFromSDLRenderer(renderer);
+    ABI::Windows::Foundation::Rect coreWindowBounds;
 
-    if (coreWindow->Bounds.Width  != data->windowSizeInDIPs.x ||
-        coreWindow->Bounds.Height != data->windowSizeInDIPs.y ||
+    result = coreWindow->get_Bounds(&coreWindowBounds);
+    if (FAILED(result)) {
+        WIN_SetErrorFromHRESULT(__FUNCTION__ ", Get Window Bounds", result);
+        return result;
+    }
+
+    if (coreWindowBounds.Width  != data->windowSizeInDIPs.x ||
+        coreWindowBounds.Height != data->windowSizeInDIPs.y ||
         data->orientation != DisplayProperties::CurrentOrientation)
     {
         ID3D11RenderTargetView* nullViews[] = {nullptr};

src/video/windowsrt/SDL_winrtvideo.cpp

@@ -172,7 +172,7 @@ WINRT_CreateWindow(_THIS, SDL_Window * window)
     }
     window->driverdata = data;
     data->sdlWindow = window;
-    data->coreWindow = new CoreWindow^(CoreWindow::GetForCurrentThread());
+    data->coreWindow = CoreWindow::GetForCurrentThread();
 
     /* Make sure the window is considered to be positioned at {0,0},
        and is considered fullscreen, shown, and the like.
@@ -233,13 +233,6 @@ WINRT_DestroyWindow(_THIS, SDL_Window * window)
     }
 
     if (data) {
-        // Delete the reference to the WinRT CoreWindow:
-        CoreWindow ^* windowPointer = ((SDL_WindowData *) window->driverdata)->coreWindow;
-        if (windowPointer) {
-            *windowPointer = nullptr;   // Clear the C++/CX reference to the CoreWindow
-            delete windowPointer;       // Delete the C++/CX reference itself
-        }
-
         // Delete the internal window data:
         delete data;
         data = NULL;
@@ -250,11 +243,10 @@ SDL_bool
 WINRT_GetWindowWMInfo(_THIS, SDL_Window * window, SDL_SysWMinfo * info)
 {
     SDL_WindowData * data = (SDL_WindowData *) window->driverdata;
-    CoreWindow ^* windowPointer = data->coreWindow;
 
     if (info->version.major <= SDL_MAJOR_VERSION) {
         info->subsystem = SDL_SYSWM_WINDOWSRT;
-        info->info.winrt.window = windowPointer;
+        info->info.winrt.window = reinterpret_cast<IUnknown *>(data->coreWindow.Get());
         return SDL_TRUE;
     } else {
         SDL_SetError("Application not compiled with SDL %d.%d\n",

src/video/windowsrt/SDL_winrtvideo.h

@@ -27,10 +27,12 @@ extern "C" {
 #include "../SDL_sysvideo.h"
 }
 
+#include <agile.h>
+
 struct SDL_WindowData
 {
     SDL_Window *sdlWindow;
-    Windows::UI::Core::CoreWindow ^* coreWindow;
+    Platform::Agile<Windows::UI::Core::CoreWindow> coreWindow;
 };
 
 #endif /* _SDL_winrtvideo_h */