I have a function that essentially takes a screen shot and saves a pointer to it as a structure. I would like to use the same structure for bitmaps that I load from files.
Code:
typedef struct _BITMAPCAPTURE {
HBITMAP hbm;
LPDWORD pixels;
INT width;
INT height;
} BITMAPCAPTURE;
BOOL CaptureScreen(BITMAPCAPTURE* bmpCapture)
{
BOOL bResult = FALSE;
if(!bmpCapture)
return bResult;
ZeroMemory(bmpCapture, sizeof(BITMAPCAPTURE));
HDC hdcScreen = GetDC(NULL);
HDC hdcCapture = CreateCompatibleDC(NULL);
int nWidth = GetSystemMetrics(SM_CXVIRTUALSCREEN),
nHeight = GetSystemMetrics(SM_CYVIRTUALSCREEN);
// Bitmap is stored top down as BGRA,BGRA,BGRA when used as
// DWORDs endianess would change it to ARGB.. windows COLORREF is ABGR
LPBYTE lpCapture;
BITMAPINFO bmiCapture = { {
sizeof(BITMAPINFOHEADER), nWidth, -nHeight, 1, 32, BI_RGB, 0, 0, 0, 0, 0,
} };
bmpCapture->hbm = CreateDIBSection(hdcScreen, &bmiCapture,
DIB_RGB_COLORS, (LPVOID *)&lpCapture, NULL, 0);
if(bmpCapture->hbm){
HBITMAP hbmOld = (HBITMAP)SelectObject(hdcCapture, bmpCapture->hbm);
BitBlt(hdcCapture, 0, 0, nWidth, nHeight, hdcScreen, 0, 0, SRCCOPY);
SelectObject(hdcCapture, hbmOld);
bmpCapture->pixels = (LPDWORD)lpCapture;
bmpCapture->width = nWidth;
bmpCapture->height = nHeight;
bResult = TRUE;
}
DeleteDC(hdcCapture);
DeleteDC(hdcScreen);
return bResult;
}
The handle to the bitmap, as well as the width and height are all easy enough to get but I'm unsure of how to get the pixels. Thanks very much.