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

[Nikolay Sivov]

On 3/4/20 6:35 PM, Ziqing Hui wrote:
> Hi Nikolay,
>
> I tried rendering an 32-bit bitmap with ILS_SATURATE on my win10 machine, it does make the image gray as expected. So I think I should implement ILS_SATURATE for imagelist in wine first, then fix toolbar. What do you think?
Hi,

Sure, sounds good. Please add a test for it at imagelist level, small 
4x4 / 8x8 image is enough, showing that grayscale conversion happens.
>
> Thanks,
>
> Ziqing
>
> On 3/4/20 6:28 PM, Ziqing Hui wrote:
>> No, I didn't check it. I don't know this flag before. I'll give it a try.
>>
>> On 3/4/20 6:04 PM, Nikolay Sivov wrote:
>>> 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?
>>>