Re: [PATCH 0/3] MR6025: winewayland: Support shaped and transparent windows.

[Alexandros Frantzis (＠afrantzis)]

Alexandros Frantzis (@afrantzis) commented about dlls/winewayland.drv/window_surface.c:
>      if (width_bytes == src_stride && width_bytes == dst_stride)
>      {
>          memcpy(dst, src, height * width_bytes);
> -
>        for (x = 3; x < height * width_bytes; x += bpp) dst[x] = 0xff;

From a few synthetic benchmarks I ran locally, this change has a significant performance impact (1.7x-3x compared to just doing the memcpy, with higher overheads for smaller regions).

Switching to a manual 32-bit pixel copy while setting the alpha is a definite improvement, with the results I am seeing being in the range of 1.2x-2x compared to just the memcpy:

```
width = rc.right - rc.left;
for (x = 0; x < height * width; ++x)                                         
    ((UINT32 *)dst)[x] = ((UINT32 *)src)[x] | 0xff000000;
```

So perhaps it's worth switching to such a loop?