video/windows: ANSI/UNICODE updates (cf. bug 5435):

- explicitly use UNICODE versions of DrawText, EnumDisplaySettings,
  EnumDisplayDevices, and CreateDC: the underlying structures have
  WCHAR strings.
- change WIN_UpdateDisplayMode and WIN_GetDisplayMode() to accept
  LPCWSTR instead of LPCTSTR for the same reason.
- change WIN_StringToUTF8 and WIN_UTF8ToString to the explicit 'W'
  versions where appropriate.
diff --git a/src/video/windows/SDL_windowskeyboard.c b/src/video/windows/SDL_windowskeyboard.c
index 964d61c..157ec2a 100644
--- a/src/video/windows/SDL_windowskeyboard.c
+++ b/src/video/windows/SDL_windowskeyboard.c
@@ -749,7 +749,7 @@
 IME_SendInputEvent(SDL_VideoData *videodata)
 {
     char *s = 0;
-    s = WIN_StringToUTF8(videodata->ime_composition);
+    s = WIN_StringToUTF8W(videodata->ime_composition);
     SDL_SendKeyboardText(s);
     SDL_free(s);
 
@@ -774,7 +774,7 @@
     else {
         SDL_wcslcpy(buffer, videodata->ime_composition, size);
     }
-    s = WIN_StringToUTF8(buffer);
+    s = WIN_StringToUTF8W(buffer);
     SDL_SendEditingText(s, videodata->ime_cursor + (int)SDL_wcslen(videodata->ime_readingstring), 0);
     SDL_free(s);
 }
diff --git a/src/video/windows/SDL_windowsmessagebox.c b/src/video/windows/SDL_windowsmessagebox.c
index 78b81fd..5e5fda8 100644
--- a/src/video/windows/SDL_windowsmessagebox.c
+++ b/src/video/windows/SDL_windowsmessagebox.c
@@ -260,7 +260,7 @@
         string = "";
     }
 
-    wstring = WIN_UTF8ToString(string);
+    wstring = WIN_UTF8ToStringW(string);
     if (!wstring) {
         return SDL_FALSE;
     }
@@ -645,9 +645,9 @@
     }
 
     /* Measure the *pixel* size of the string. */
-    wmessage = WIN_UTF8ToString(messageboxdata->message);
+    wmessage = WIN_UTF8ToStringW(messageboxdata->message);
     SDL_zero(TextSize);
-    DrawText(FontDC, wmessage, -1, &TextSize, DT_CALCRECT | DT_LEFT | DT_NOPREFIX | DT_EDITCONTROL);
+    DrawTextW(FontDC, wmessage, -1, &TextSize, DT_CALCRECT | DT_LEFT | DT_NOPREFIX | DT_EDITCONTROL);
 
     /* Add margins and some padding for hangs, etc. */
     TextSize.left += TextMargin;
@@ -822,8 +822,8 @@
         ParentWindow = ((SDL_WindowData *) messageboxdata->window->driverdata)->hwnd;
     }
 
-    wmessage = WIN_UTF8ToString(messageboxdata->message);
-    wtitle = WIN_UTF8ToString(messageboxdata->title);
+    wmessage = WIN_UTF8ToStringW(messageboxdata->message);
+    wtitle = WIN_UTF8ToStringW(messageboxdata->title);
 
     SDL_zero(TaskConfig);
     TaskConfig.cbSize = sizeof (TASKDIALOGCONFIG);
@@ -872,7 +872,7 @@
             SDL_free(pButtons);
             return -1;
         }
-        pButton->pszButtonText = WIN_UTF8ToString(buttontext);
+        pButton->pszButtonText = WIN_UTF8ToStringW(buttontext);
         if (messageboxdata->buttons[i].flags & SDL_MESSAGEBOX_BUTTON_RETURNKEY_DEFAULT) {
             TaskConfig.nDefaultButton = pButton->nButtonID;
         }
diff --git a/src/video/windows/SDL_windowsmodes.c b/src/video/windows/SDL_windowsmodes.c
index 93eb84d..e8b1fc1 100644
--- a/src/video/windows/SDL_windowsmodes.c
+++ b/src/video/windows/SDL_windowsmodes.c
@@ -32,7 +32,7 @@
 /* #define DEBUG_MODES */
 
 static void
-WIN_UpdateDisplayMode(_THIS, LPCTSTR deviceName, DWORD index, SDL_DisplayMode * mode)
+WIN_UpdateDisplayMode(_THIS, LPCWSTR deviceName, DWORD index, SDL_DisplayMode * mode)
 {
     SDL_DisplayModeData *data = (SDL_DisplayModeData *) mode->driverdata;
     HDC hdc;
@@ -109,14 +109,14 @@
 }
 
 static SDL_bool
-WIN_GetDisplayMode(_THIS, LPCTSTR deviceName, DWORD index, SDL_DisplayMode * mode)
+WIN_GetDisplayMode(_THIS, LPCWSTR deviceName, DWORD index, SDL_DisplayMode * mode)
 {
     SDL_DisplayModeData *data;
     DEVMODE devmode;
 
     devmode.dmSize = sizeof(devmode);
     devmode.dmDriverExtra = 0;
-    if (!EnumDisplaySettings(deviceName, index, &devmode)) {
+    if (!EnumDisplaySettingsW(deviceName, index, &devmode)) {
         return SDL_FALSE;
     }
 
@@ -145,10 +145,10 @@
     SDL_VideoDisplay display;
     SDL_DisplayData *displaydata;
     SDL_DisplayMode mode;
-    DISPLAY_DEVICE device;
+    DISPLAY_DEVICEW device;
 
 #ifdef DEBUG_MODES
-    SDL_Log("Display: %s\n", WIN_StringToUTF8(info->szDevice));
+    SDL_Log("Display: %s\n", WIN_StringToUTF8W(info->szDevice));
 #endif
 
     if (!WIN_GetDisplayMode(_this, info->szDevice, ENUM_CURRENT_SETTINGS, &mode)) {
@@ -178,8 +178,8 @@
 
     SDL_zero(display);
     device.cb = sizeof(device);
-    if (EnumDisplayDevices(info->szDevice, 0, &device, 0)) {
-        display.name = WIN_StringToUTF8(device.DeviceString);
+    if (EnumDisplayDevicesW(info->szDevice, 0, &device, 0)) {
+        display.name = WIN_StringToUTF8W(device.DeviceString);
     }
     display.desktop_mode = mode;
     display.current_mode = mode;
@@ -383,9 +383,9 @@
     LONG status;
 
     if (mode->driverdata == display->desktop_mode.driverdata) {
-        status = ChangeDisplaySettingsEx(displaydata->DeviceName, NULL, NULL, CDS_FULLSCREEN, NULL);
+        status = ChangeDisplaySettingsExW(displaydata->DeviceName, NULL, NULL, CDS_FULLSCREEN, NULL);
     } else {
-        status = ChangeDisplaySettingsEx(displaydata->DeviceName, &data->DeviceMode, NULL, CDS_FULLSCREEN, NULL);
+        status = ChangeDisplaySettingsExW(displaydata->DeviceName, &data->DeviceMode, NULL, CDS_FULLSCREEN, NULL);
     }
     if (status != DISP_CHANGE_SUCCESSFUL) {
         const char *reason = "Unknown reason";
@@ -405,7 +405,7 @@
         }
         return SDL_SetError("ChangeDisplaySettingsEx() failed: %s", reason);
     }
-    EnumDisplaySettings(displaydata->DeviceName, ENUM_CURRENT_SETTINGS, &data->DeviceMode);
+    EnumDisplaySettingsW(displaydata->DeviceName, ENUM_CURRENT_SETTINGS, &data->DeviceMode);
     WIN_UpdateDisplayMode(_this, displaydata->DeviceName, ENUM_CURRENT_SETTINGS, mode);
     return 0;
 }
diff --git a/src/video/windows/SDL_windowsvideo.c b/src/video/windows/SDL_windowsvideo.c
index f0a5da9..9ef9360 100644
--- a/src/video/windows/SDL_windowsvideo.c
+++ b/src/video/windows/SDL_windowsvideo.c
@@ -184,7 +184,7 @@
     device->GL_GetSwapInterval = WIN_GL_GetSwapInterval;
     device->GL_SwapWindow = WIN_GL_SwapWindow;
     device->GL_DeleteContext = WIN_GL_DeleteContext;
-#elif SDL_VIDEO_OPENGL_EGL        
+#elif SDL_VIDEO_OPENGL_EGL
     /* Use EGL based functions */
     device->GL_LoadLibrary = WIN_GLES_LoadLibrary;
     device->GL_GetProcAddress = WIN_GLES_GetProcAddress;
@@ -249,7 +249,7 @@
 #define D3D_DEBUG_INFO
 #include <d3d9.h>
 
-SDL_bool 
+SDL_bool
 D3D_LoadDLL(void **pD3DDLL, IDirect3D9 **pDirect3D9Interface)
 {
     *pD3DDLL = SDL_LoadObject("D3D9.DLL");
@@ -308,7 +308,7 @@
             SDL_SetError("Invalid display index");
             adapterIndex = -1; /* make sure we return something invalid */
         } else {
-            char *displayName = WIN_StringToUTF8(pData->DeviceName);
+            char *displayName = WIN_StringToUTF8W(pData->DeviceName);
             unsigned int count = IDirect3D9_GetAdapterCount(pD3D);
             unsigned int i;
             for (i=0; i<count; i++) {
@@ -407,14 +407,14 @@
         return SDL_FALSE;
     }
 
-    displayName = WIN_StringToUTF8(pData->DeviceName);
+    displayName = WIN_StringToUTF8W(pData->DeviceName);
     nAdapter = 0;
     while (*adapterIndex == -1 && SUCCEEDED(IDXGIFactory_EnumAdapters(pDXGIFactory, nAdapter, &pDXGIAdapter))) {
         nOutput = 0;
         while (*adapterIndex == -1 && SUCCEEDED(IDXGIAdapter_EnumOutputs(pDXGIAdapter, nOutput, &pDXGIOutput))) {
             DXGI_OUTPUT_DESC outputDesc;
             if (SUCCEEDED(IDXGIOutput_GetDesc(pDXGIOutput, &outputDesc))) {
-                char *outputName = WIN_StringToUTF8(outputDesc.DeviceName);
+                char *outputName = WIN_StringToUTF8W(outputDesc.DeviceName);
                 if (SDL_strcmp(outputName, displayName) == 0) {
                     *adapterIndex = nAdapter;
                     *outputIndex = nOutput;
diff --git a/src/video/windows/SDL_windowswindow.c b/src/video/windows/SDL_windowswindow.c
index e39ed08..2a54eb2 100644
--- a/src/video/windows/SDL_windowswindow.c
+++ b/src/video/windows/SDL_windowswindow.c
@@ -708,7 +708,7 @@
     HDC hdc;
     BOOL succeeded = FALSE;
 
-    hdc = CreateDC(data->DeviceName, NULL, NULL, NULL);
+    hdc = CreateDCW(data->DeviceName, NULL, NULL, NULL);
     if (hdc) {
         succeeded = SetDeviceGammaRamp(hdc, (LPVOID)ramp);
         if (!succeeded) {
@@ -727,7 +727,7 @@
     HDC hdc;
     BOOL succeeded = FALSE;
 
-    hdc = CreateDC(data->DeviceName, NULL, NULL, NULL);
+    hdc = CreateDCW(data->DeviceName, NULL, NULL, NULL);
     if (hdc) {
         succeeded = GetDeviceGammaRamp(hdc, (LPVOID)ramp);
         if (!succeeded) {