Thread: workarround with CreateDIBSection

Hi all,

i would like to scan a certain range of my desktop for a certain pixel colour
in always recurring distances. The whole should run in the background (i use WinXP
Prof) and as fast as possible. First i tried it with "GetPixel" (see the code with
GetPixel) and i could do it successfully. But the handicap is that with bigger
ranges "GetPixel" is simply to slow!

In the meantime i have read that there is a quicker possibility with "CreateDIBSection"
Now i tried to do the same work with "CreateDIBSectio" but i couldnt resovlve that
problem. Can anybody help me and give me a codesnippet that do the same work as the
GetPixel-code-example? It would be very very nice :-)


regards, rommi (C++ Beginner)


****** code with GetPixel ************

Code:

int x, y;
HDC dc = GetDC(0);
int seekpix = 16777215;

while(true)
{
   for(x=100; x < 500; x++)
   {		
	for(y=200; y < 800; y++)
	{
	   //=========== Desktop-Pixelfarbe ermitteln
	   COLORREF deskpix = GetPixel(dc, y, x);

	   //=========== Desktop-Pixelfarbe mit Suchpixel vergleich
	   if(deskpix == seekpix)
	   {
		    //execute further code
	   }
	}
   }
}

****** my try with CreateDIBSection *****

Code:

	// Deklaration
	HDC hdc_screen;
	BITMAPINFO    bmi;
	LPBYTE      pBits;
	int x=500;
	int y=800;

	// window-id
	HWND desktopHandle = GetDesktopWindow();

	// device-context
	hdc_screen = GetDC(desktopHandle);

	// clean
	ZeroMemory(&bmi, sizeof(bmi));

	// Parameter DIBSection
	bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);
	bmi.bmiHeader.biWidth        = x;
	bmi.bmiHeader.biHeight        = y;
	bmi.bmiHeader.biPlanes        = 1;
	bmi.bmiHeader.biBitCount    = 24;
	bmi.bmiHeader.biCompression = BI_RGB;

	// Create DibSection	
	HBITMAP hdcBmp = CreateDIBSection(hdc_screen, &bmi, DIB_RGB_COLORS, (void **)&pBits, NULL, 0);

	// ??????
	// ??????