capture bitmap de fenetre

bonsoir,

jai essaye de capturer les pixels de la fenetre (pour en faire une texture
opengl garce a un tableau de unsigned char *data=0)mais ca ne marche pas.

voila le code que jai essayé


RECT rc;
HDC hMemDC=NULL;
HBITMAP hBmp=NULL;

HDC hDC=NULL
GetWindowRect((HWND)cwps.hwnd, &rc);
hDc = CreateDC("DISPLAY", NULL, NULL, NULL);
hMemDC = CreateCompatibleDC(GetDC(0));

BITMAPINFO bi = {0};
DWORD *pBits = 0;

bi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bi.bmiHeader.biBitCount = 24;
bi.bmiHeader.biWidth = (rc.right - rc.left);
bi.bmiHeader.biHeight = (rc.bottom - rc.top);
bi.bmiHeader.biCompression = BI_RGB;
bi.bmiHeader.biPlanes = 1;
hBmp = CreateDIBSection(hMemDC,&bi,DIB_RGB_COLORS,(void**)&data,0,0);
if(!hBmp)
{
DeleteDC(hMemDC);
// erreurrrrrrrrrrr
}

SelectObject(hMemDC, hBmp);
StretchBlt(hMemDC, 0, 0,
128,128,GetDC((HWND)cwps.hwnd),0,0,bi.bmiHeader.biWidth,bi.bmiHeader.biHeigh
t, SRCCOPY);


DeleteDC(hMemDC);