Re: gdiplus: Blend in the background colour.

[Vincent Povirk]

> - return ((b     + ((BYTE)bkgnd         * (255 - alpha) + 127) / 255) |

What's the purpose of adding 127 here?
>      stat = GdipBitmapLockBits(bitmap, NULL, ImageLockModeRead|ImageLockModeUserInputBuf,
>          PixelFormat32bppPARGB, &lockeddata);
>
> -
>    if (background & 0xffffff)
> -
>    {
> -
>        DWORD *ptr;
> -
>        UINT i;
> -
>        for (ptr = (DWORD*)bits, i = 0; i < width * height; ptr++, i++)
> -
>        {
> -
>            if ((*ptr & 0xff000000) == 0xff000000) continue;
> -
>            *ptr = blend_argb_no_bkgnd_alpha(*ptr, background);
> -
>        }
> -
>    }

I guess it wouldn't hurt anything, but it doesn't make much sense to
do this if LockBits fails.