Re: [PATCH 2/2] comctl32/toolbar: Correctly draw disabled toolbar button which contains 32 bpp bitmap with alpha channel.

[Nikolay Sivov]

On 3/4/20 12:42 PM, Ziqing Hui wrote:
> - has_alpha = FALSE;
> - if (bmp.bmBitsPixel == 32)
> - {
> -
>    for (pixel = bits; pixel < bits + cx * cy; pixel++)
> -
>    {
> -
>        if ((*pixel >> 24) != 0)
> -
>        {
> -
>            has_alpha = TRUE;
> -
>            break;
> -
>        }
> -
>    }
> - }
> -
> - if (has_alpha)
> - {
> -
>    /* gray the src image */
> -
>    for (pixel = bits; pixel < bits + cx * cy; pixel++)
> -
>    {
> -
>        DWORD alpha = (*pixel >> 24) & 0x000000ff;
> -
>        DWORD red   = (*pixel >> 16) & 0x000000ff;
> -
>        DWORD green = (*pixel >> 8)  & 0x000000ff;
> -
>        DWORD blue  = (*pixel)       & 0x000000ff;
> -
>        DWORD gray = (red * 299 + green * 587 + blue * 114) / 1000;
> -
>        gray = gray * alpha / 0xff;
> -
>        *pixel = ((alpha << 24) | (gray << 16) | (gray << 8) | gray);
> -
>    }
> -
>    bf.BlendOp = AC_SRC_OVER;
> -
>    bf.BlendFlags = 0;
> -
>    bf.SourceConstantAlpha = 0xff;
> -
>    bf.AlphaFormat = AC_SRC_ALPHA;
> -
>    GdiAlphaBlend(hdc, x, y, cx, cy, hdcImage, 0, 0, cx, cy, bf);
> -
>    goto done;
> - }
> -

I think it's possible ILS_SATURATE should be used for that. Have you 
checked rendering on Windows with this flag?