Fixed various build and runtime errors when using WinRT with VS2012.

src/core/winrt/SDL_winrtapp_xaml.cpp

@@ -42,7 +42,7 @@
 SDL_bool WINRT_XAMLWasEnabled = SDL_FALSE;
 
 #if WINAPI_FAMILY == WINAPI_FAMILY_APP
-ISwapChainBackgroundPanelNative * WINRT_GlobalSwapChainBackgroundPanelNative = NULL;
+extern "C" ISwapChainBackgroundPanelNative * WINRT_GlobalSwapChainBackgroundPanelNative = NULL;
 static Windows::Foundation::EventRegistrationToken	WINRT_XAMLAppEventToken;
 #endif
 

src/dynapi/SDL_dynapi.h

@@ -45,6 +45,8 @@
 
 #if TARGET_OS_IPHONE  /* probably not useful on iOS. */
 #define SDL_DYNAMIC_API 0
+#elif SDL_BUILDING_WINRT /* probaly not useful on WinRT, given current .dll loading restrictions */
+#define SDL_DYNAMIC_API 0
 #else   /* everyone else. */
 #define SDL_DYNAMIC_API 1
 #endif

src/power/SDL_power.c

@@ -37,6 +37,7 @@ SDL_bool SDL_GetPowerInfo_Haiku(SDL_PowerState *, int *, int *);
 SDL_bool SDL_GetPowerInfo_UIKit(SDL_PowerState *, int *, int *);
 SDL_bool SDL_GetPowerInfo_Android(SDL_PowerState *, int *, int *);
 SDL_bool SDL_GetPowerInfo_PSP(SDL_PowerState *, int *, int *);
+SDL_bool SDL_GetPowerInfo_WinRT(SDL_PowerState *, int *, int *);
 
 #ifndef SDL_POWER_DISABLED
 #ifdef SDL_POWER_HARDWIRED
@@ -77,6 +78,9 @@ static SDL_GetPowerInfo_Impl implementations[] = {
 #ifdef SDL_POWER_PSP        /* handles PSP. */
     SDL_GetPowerInfo_PSP,
 #endif
+#ifdef SDL_POWER_WINRT          /* handles WinRT */
+    SDL_GetPowerInfo_WinRT,
+#endif
 
 #ifdef SDL_POWER_HARDWIRED
     SDL_GetPowerInfo_Hardwired,

src/render/direct3d11/SDL_render_d3d11.c

@@ -961,11 +961,10 @@ D3D11_CreateDeviceResources(SDL_Renderer * renderer)
     D3D11_SAMPLER_DESC samplerDesc;
     D3D11_RASTERIZER_DESC rasterDesc;
 
-    // TODO, WinRT, Mar 11, 2014: once SDL/WinRT is back up and running, see if D3D11 init functions are loadable (via LoadPackagedLibrary/SDL_LoadObject, etc.)
-//#ifdef __WINRT__
-//    CreateDXGIFactoryFunc = CreateDXGIFactory;
-//    D3D11CreateDeviceFunc = D3D11CreateDevice;
-//#else
+#ifdef __WINRT__
+    CreateDXGIFactoryFunc = CreateDXGIFactory1;
+    D3D11CreateDeviceFunc = D3D11CreateDevice;
+#else
     data->hDXGIMod = SDL_LoadObject("dxgi.dll");
     if (!data->hDXGIMod) {
         result = E_FAIL;
@@ -989,7 +988,7 @@ D3D11_CreateDeviceResources(SDL_Renderer * renderer)
         result = E_FAIL;
         goto done;
     }
-//#endif /* __WINRT__ */
+#endif /* __WINRT__ */
 
     result = CreateDXGIFactoryFunc(&IID_IDXGIFactory2, &data->dxgiFactory);
     if (FAILED(result)) {
@@ -2833,6 +2832,11 @@ D3D11_RenderPresent(SDL_Renderer * renderer)
     HRESULT result;
     DXGI_PRESENT_PARAMETERS parameters;
 
+#if WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP
+    syncInterval = 1;
+    presentFlags = 0;
+    result = IDXGISwapChain_Present(data->swapChain, syncInterval, presentFlags);
+#else
     if (renderer->info.flags & SDL_RENDERER_PRESENTVSYNC) {
         syncInterval = 1;
         presentFlags = 0;
@@ -2841,9 +2845,6 @@ D3D11_RenderPresent(SDL_Renderer * renderer)
         presentFlags = DXGI_PRESENT_DO_NOT_WAIT;
     }
 
-#if WINAPI_FAMILY == WINAPI_FAMILY_PHONE_APP
-    result = IDXGISwapChain_Present(data->swapChain, syncInterval, presentFlags);
-#else
     /* The application may optionally specify "dirty" or "scroll"
      * rects to improve efficiency in certain scenarios.
      * This option is not available on Windows Phone 8, to note.

src/render/direct3d11/SDL_render_d3d11_winrthelpers.cpp

@@ -37,6 +37,8 @@ extern "C" {
 using namespace Windows::UI::Core;
 using namespace Windows::Graphics::Display;
 
+#include <DXGI.h>
+
 
 extern "C" void *
 D3D11_GetCoreWindowFromSDLRenderer(SDL_Renderer * renderer)

src/thread/stdcpp/SDL_sysmutex.cpp

@@ -79,6 +79,21 @@ SDL_mutexP(SDL_mutex * mutex)
     }
 }
 
+/* TryLock the mutex */
+int
+SDL_TryLockMutex(SDL_mutex * mutex)
+{
+    int retval = 0;
+    if (mutex == NULL) {
+        return SDL_SetError("Passed a NULL mutex");
+    }
+
+    if (mutex->cpp_mutex.try_lock() == false) {
+        retval = SDL_MUTEX_TIMEDOUT;
+    }
+    return retval;
+}
+
 /* Unlock the mutex */
 extern "C"
 int