From ae27ea7329561c939058579f45154e7905042478 Mon Sep 17 00:00:00 2001
From: Sebastian Lackner <sebastian@fds-team.de>
Date: Tue, 24 Jan 2017 12:37:46 +0100
Subject: winex11: Fix alpha blending in X11DRV_UpdateLayeredWindow.

Based on a patch by Dmitry Timoshkov.
---
 dlls/winex11.drv/window.c | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/dlls/winex11.drv/window.c b/dlls/winex11.drv/window.c
index eaf6dcfa3ed..5dec74acae7 100644
--- a/dlls/winex11.drv/window.c
+++ b/dlls/winex11.drv/window.c
@@ -410,14 +410,11 @@ static void sync_window_region( struct x11drv_win_data *data, HRGN win_region )
 
 
 /***********************************************************************
- *              sync_window_opacity
+ *              set_window_opacity
  */
-static void sync_window_opacity( Display *display, Window win,
-                                 COLORREF key, BYTE alpha, DWORD flags )
+static void set_window_opacity( Display *display, Window win, BYTE alpha )
 {
-    unsigned long opacity = 0xffffffff;
-
-    if (flags & LWA_ALPHA) opacity = (0xffffffff / 0xff) * alpha;
+    unsigned long opacity = (0xffffffff / 0xff) * alpha;
 
     if (opacity == 0xffffffff)
         XDeleteProperty( display, win, x11drv_atom(_NET_WM_WINDOW_OPACITY) );
@@ -1527,7 +1524,7 @@ static void create_whole_window( struct x11drv_win_data *data )
 
     /* set the window opacity */
     if (!GetLayeredWindowAttributes( data->hwnd, &key, &alpha, &layered_flags )) layered_flags = 0;
-    sync_window_opacity( data->display, data->whole_window, key, alpha, layered_flags );
+    set_window_opacity( data->display, data->whole_window, (layered_flags & LWA_ALPHA) ? alpha : 0xff );
 
     XFlush( data->display );  /* make sure the window exists before we start painting to it */
 
@@ -1647,7 +1644,7 @@ void CDECL X11DRV_SetWindowStyle( HWND hwnd, INT offset, STYLESTRUCT *style )
     {
         data->layered = FALSE;
         set_window_visual( data, &default_visual );
-        sync_window_opacity( data->display, data->whole_window, 0, 0, 0 );
+        set_window_opacity( data->display, data->whole_window, 0xff );
         if (data->surface) set_surface_color_key( data->surface, CLR_INVALID );
     }
 done:
@@ -2538,7 +2535,7 @@ void CDECL X11DRV_SetLayeredWindowAttributes( HWND hwnd, COLORREF key, BYTE alph
         set_window_visual( data, &default_visual );
 
         if (data->whole_window)
-            sync_window_opacity( data->display, data->whole_window, key, alpha, flags );
+            set_window_opacity( data->display, data->whole_window, (flags & LWA_ALPHA) ? alpha : 0xff );
         if (data->surface)
             set_surface_color_key( data->surface, (flags & LWA_COLORKEY) ? key : CLR_INVALID );
 
@@ -2562,7 +2559,7 @@ void CDECL X11DRV_SetLayeredWindowAttributes( HWND hwnd, COLORREF key, BYTE alph
         Window win = X11DRV_get_whole_window( hwnd );
         if (win)
         {
-            sync_window_opacity( gdi_display, win, key, alpha, flags );
+            set_window_opacity( gdi_display, win, (flags & LWA_ALPHA) ? alpha : 0xff );
             if (flags & LWA_COLORKEY)
                 FIXME( "LWA_COLORKEY not supported on foreign process window %p\n", hwnd );
         }
@@ -2578,7 +2575,6 @@ BOOL CDECL X11DRV_UpdateLayeredWindow( HWND hwnd, const UPDATELAYEREDWINDOWINFO
 {
     struct window_surface *surface;
     struct x11drv_win_data *data;
-    BLENDFUNCTION blend = { AC_SRC_OVER, 0, 255, 0 };
     COLORREF color_key = (info->dwFlags & ULW_COLORKEY) ? info->crKey : CLR_INVALID;
     char buffer[FIELD_OFFSET( BITMAPINFO, bmiColors[256] )];
     BITMAPINFO *bmi = (BITMAPINFO *)buffer;
@@ -2606,6 +2602,10 @@ BOOL CDECL X11DRV_UpdateLayeredWindow( HWND hwnd, const UPDATELAYEREDWINDOWINFO
     }
     else set_surface_color_key( surface, color_key );
 
+    if (data->whole_window)
+        set_window_opacity( data->display, data->whole_window,
+                            (info->dwFlags & ULW_ALPHA) ? info->pblend->SourceConstantAlpha : 0xff );
+
     if (surface) window_surface_add_ref( surface );
     release_win_data( data );
 
@@ -2629,16 +2629,15 @@ BOOL CDECL X11DRV_UpdateLayeredWindow( HWND hwnd, const UPDATELAYEREDWINDOWINFO
     {
         IntersectRect( &rect, &rect, info->prcDirty );
         memcpy( src_bits, dst_bits, bmi->bmiHeader.biSizeImage );
-        PatBlt( hdc, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, BLACKNESS );
     }
     src_rect = rect;
     if (info->pptSrc) OffsetRect( &src_rect, info->pptSrc->x, info->pptSrc->y );
     DPtoLP( info->hdcSrc, (POINT *)&src_rect, 2 );
 
-    ret = GdiAlphaBlend( hdc, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,
-                         info->hdcSrc, src_rect.left, src_rect.top,
-                         src_rect.right - src_rect.left, src_rect.bottom - src_rect.top,
-                         (info->dwFlags & ULW_ALPHA) ? *info->pblend : blend );
+    ret = StretchBlt( hdc, rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top,
+                      info->hdcSrc, src_rect.left, src_rect.top,
+                      src_rect.right - src_rect.left, src_rect.bottom - src_rect.top,
+                      SRCCOPY );
     if (ret)
     {
         memcpy( dst_bits, src_bits, bmi->bmiHeader.biSizeImage );
-- 
2.13.1