Revert "W32: RGBA GDK backend (broken)"

This reverts commit f89d38bc2d.

Pushed by accident.

configure.ac

@@ -363,25 +363,6 @@ fi
 AC_SUBST(ENABLE_ON_X11)
 
 if test "$enable_win32_backend" = "yes"; then
-  AC_MSG_CHECKING([for DWM])
-  AC_LINK_IFELSE([
-    AC_LANG_PROGRAM([[
-        #include <windows.h>
-        #include <dwmapi.h>
-      ]],
-      [[
-        DWM_BLURBEHIND bb;
-        memset (&bb, 0, sizeof (bb));
-        bb.dwFlags = DWM_BB_ENABLE | DWM_BB_BLURREGION;
-      ]]
-    )],
-    [dwm_ok=yes], [dwm_ok=no]
-  )
-  AC_MSG_RESULT($dwm_ok)
-  if test "$dwm_ok" = "yes"; then
-    AC_DEFINE([HAVE_W32_DWM], [1], [Define if W32 DWM API is available])
-  fi
-
   cairo_backends="$cairo_backends cairo-win32"
   GDK_BACKENDS="$GDK_BACKENDS win32"
   backend_immodules="$backend_immodules,ime"

gdk/win32/gdkscreen-win32.c

@@ -211,7 +211,7 @@ gdk_win32_screen_class_init (GdkWin32ScreenClass *klass)
   screen_class->get_monitor_geometry = gdk_win32_screen_get_monitor_geometry;
   screen_class->get_monitor_workarea = gdk_win32_screen_get_monitor_geometry;
   screen_class->get_system_visual = _gdk_win32_screen_get_system_visual;
-  screen_class->get_rgba_visual = _gdk_win32_screen_get_system_visual;
+  screen_class->get_rgba_visual = gdk_win32_screen_get_rgba_visual;
   screen_class->is_composited = gdk_win32_screen_is_composited;
   screen_class->make_display_name = gdk_win32_screen_make_display_name;
   screen_class->get_active_window = gdk_win32_screen_get_active_window;

gdk/win32/gdkvisual-win32.c

@@ -194,6 +194,7 @@ _gdk_visual_init (GdkScreen *screen)
     }
   else if (bitspixel == 24 || bitspixel == 32)
     {
+      bitspixel = 24;
       system_visual->type = GDK_VISUAL_TRUE_COLOR;
       system_visual->red_mask   = 0x00FF0000;
       system_visual->green_mask = 0x0000FF00;

gdk/win32/gdkwindow-win32.c

@@ -38,9 +38,6 @@
 #include "gdkdisplayprivate.h"
 #include "gdkvisualprivate.h"
 #include "gdkwin32window.h"
-#ifdef HAVE_W32_DWM
-#include <dwmapi.h>
-#endif
 
 #include <cairo-win32.h>
 
@@ -687,45 +684,6 @@ _gdk_win32_display_create_window_impl (GdkDisplay    *display,
 
   if (attributes_mask & GDK_WA_CURSOR)
     gdk_window_set_cursor (window, attributes->cursor);
-
-/* HAVE_W32_DWM means that we have necessary declarations at compile-time,
- * but we'd still like to be able to run on XP, so we'll load the only non-XP
- * function we need here at runtime.
- */
-#ifdef HAVE_W32_DWM
-  {
-    typedef HRESULT (WINAPI *PFN_DwmEnableBlurBehindWindow)(HWND,
-        const DWM_BLURBEHIND *);
-    HMODULE dwmdll;
-    PFN_DwmEnableBlurBehindWindow dwmEnableBlurBehindWindow = NULL;
-
-    dwmdll = GetModuleHandle ("dwmapi.dll");
-    dwmEnableBlurBehindWindow = (PFN_DwmEnableBlurBehindWindow)
-        GetProcAddress (dwmdll, "DwmEnableBlurBehindWindow");
-
-    if (dwmEnableBlurBehindWindow)
-      {
-        /* Enable blurbehind, but give it an empty region, leaving us
-           with all the transparency with none of the blur */
-        DWM_BLURBEHIND bb;
-        HRGN hRgn;
-        hRgn = CreateRectRgn (0, 0, -1, -1);
-        if (hRgn != NULL)
-          {
-            HRESULT hr;
-            memset (&bb, 0, sizeof (bb));
-            bb.dwFlags = DWM_BB_ENABLE | DWM_BB_BLURREGION;
-            bb.hRgnBlur = hRgn;
-            bb.fEnable = TRUE;
-            hr = dwmEnableBlurBehindWindow (GDK_WINDOW_HWND (window), &bb);
-            if (S_OK != hr)
-              g_warning ("%s: %s failed: %" G_GINT64_MODIFIER "x", G_STRLOC,
-                  "DwmEnableBlurBehindWindow", (guint64) hr);
-            DeleteObject (hRgn);
-          }
-      }
-  }
-#endif
 }
 
 GdkWindow *
@@ -3429,7 +3387,7 @@ gdk_win32_ref_cairo_surface (GdkWindow *window)
       if (!hdc)
 	return NULL;
 
-      impl->cairo_surface = cairo_win32_surface_create_with_alpha (hdc);
+      impl->cairo_surface = cairo_win32_surface_create (hdc);
 
       cairo_surface_set_user_data (impl->cairo_surface, &gdk_win32_cairo_key,
 				   impl, gdk_win32_cairo_surface_destroy);