ddraw: Adjust the d3d viewport when changing the back buffer.

dlls/ddraw/device.c

@@ -306,6 +306,17 @@ IDirect3DDeviceImpl_7_Release(IDirect3DDevice7 *iface)
         /* Restore the render targets */
         if(This->OffScreenTarget)
         {
+            WINED3DVIEWPORT vp;
+
+            vp.X = 0;
+            vp.Y = 0;
+            vp.Width = This->ddraw->d3d_target->surface_desc.dwWidth;
+            vp.Height = This->ddraw->d3d_target->surface_desc.dwHeight;
+            vp.MinZ = 0.0;
+            vp.MaxZ = 1.0;
+            IWineD3DDevice_SetViewport(This->wineD3DDevice,
+                                       &vp);
+
             /* Set the device up to render to the front buffer since the back buffer will
              * vanish soon.
              */

dlls/ddraw/direct3d.c

@@ -844,6 +844,7 @@ IDirect3DImpl_7_CreateDevice(IDirect3D7 *iface,
     if(!(target->surface_desc.ddsCaps.dwCaps & DDSCAPS_PRIMARYSURFACE) &&
        (This->d3d_target != target))
     {
+        WINED3DVIEWPORT vp;
         TRACE("(%p) Using %p as front buffer, %p as back buffer\n", This, This->d3d_target, target);
         hr = IWineD3DDevice_SetFrontBackBuffers(This->wineD3DDevice,
                                                 This->d3d_target->WineD3DSurface,
@@ -855,6 +856,15 @@ IDirect3DImpl_7_CreateDevice(IDirect3D7 *iface,
         IWineD3DDevice_SetRenderTarget(This->wineD3DDevice, 0,
                                        target->WineD3DSurface);
 
+        vp.X = 0;
+        vp.Y = 0;
+        vp.Width = target->surface_desc.dwWidth;
+        vp.Height = target->surface_desc.dwHeight;
+        vp.MinZ = 0.0;
+        vp.MaxZ = 1.0;
+        IWineD3DDevice_SetViewport(This->wineD3DDevice,
+                                   &vp);
+
         object->OffScreenTarget = TRUE;
     }
     else