BitBlt trouble.

Question posted by: DumRat (Member) on June 4th, 2008 02:17 PM

Hi,
Can anyone plz help?
I have the following code for the WM_PAINT event, but it doesn't work. Need to knw why. I'm drawing the scene to the window, but am using an intermediate DC. Then it just shows a white screen, however, if I drop the intermediate DC, it works. I need to know why this fails. Thanks in advance.

Code: ( text )

case WM_PAINT:
{
HBITMAP hBm = (HBITMAP)LoadImageA(NULL, "black.bmp", IMAGE_BITMAP, 768, 768, LR_LOADFROMFILE);
HBITMAP hBmMask = (HBITMAP)LoadImageA(NULL, "blackm.bmp", IMAGE_BITMAP, 768, 768, LR_LOADFROMFILE);
HDC ourDC = CreateCompatibleDC(GetDC(hWnd));
HDC comDC = CreateCompatibleDC(ourDC);
HDC mDC = CreateCompatibleDC(ourDC);
HBITMAP old = (HBITMAP)SelectObject(comDC, hBm);
HBITMAP old2 = (HBITMAP)SelectObject(mDC, hBmMask);
BitBlt(ourDC, 0, 0, 768, 768, mDC, 0, 0, SRCAND);
BitBlt(ourDC, 0, 0, 768, 768, comDC, 0, 0, SRCPAINT);
BitBlt(GetDC(hWnd), 0, 0, 768, 768, ourDC, 0, 0, SRCCOPY);
}
break;

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romanize

Newbie

5 Posts

July 24th, 2008
12:37 PM
#2

Re: BitBlt trouble.

a late response it seems. have you found out where the problem was?
i remember having similar problems - some years ago though. did you try to createcompatibledc from the same GetDC?
r.

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