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?