C++ capture d'écran

#include "windows.h" //should be less than and greater than instead of \"
int CaptureBMP(LPCTSTR szFile)
{
//Source[1]
HDC hdcScr, hdcMem;
HBITMAP hbmScr;
BITMAP bmp;
int iXRes, iYRes;
//Create a normal DC and a memory DC for the entire screen. The
//normal DC provides a "snapshot" of the screen contents. The
//memory DC keeps a copy of this "snapshot" in the associated
//bitmap.
hdcScr = CreateDC("DISPLAY", NULL, NULL, NULL);
hdcMem = CreateCompatibleDC(hdcScr);
iXRes = GetDeviceCaps(hdcScr, HORZRES);
iYRes = GetDeviceCaps(hdcScr, VERTRES);
//Create a compatible bitmap for hdcScreen.
hbmScr = CreateCompatibleBitmap(hdcScr, iXRes, iYRes);
if (hbmScr == 0) return 0;
//Select the bitmaps into the compatible DC.
if (!SelectObject(hdcMem, hbmScr)) return 0;
//Copy color data for the entire display into a
//bitmap that is selected into a compatible DC.
if (!StretchBlt(hdcMem,
0, 0, iXRes, iYRes,
hdcScr,
0, 0, iXRes, iYRes,
SRCCOPY))
return 0;
//Source[2]
PBITMAPINFO pbmi;
WORD cClrBits;
//Retrieve the bitmap's color format, width, and height.
if (!GetObject(hbmScr, sizeof(BITMAP), (LPSTR) &bmp)) return 0;
//Convert the color format to a count of bits.
cClrBits = (WORD)(bmp.bmPlanes * bmp.bmBitsPixel);
if (cClrBits == 1)
cClrBits = 1;
else if (cClrBits <= 4)
cClrBits = 4;
else if (cClrBits <= 8)
cClrBits = 8;
else if (cClrBits <= 16)
cClrBits = 16;
else if (cClrBits <= 24)
cClrBits = 24;
else cClrBits = 32;
//Allocate memory for the BITMAPINFO structure. (This structure
//contains a BITMAPINFOHEADER structure and an array of RGBQUAD
//data structures.)
if (cClrBits != 24)
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,
sizeof(BITMAPINFOHEADER) +
sizeof(RGBQUAD) * (1 << cClrBits));
//There is no RGBQUAD array for the 24-bit-per-pixel format.
else
pbmi = (PBITMAPINFO) LocalAlloc(LPTR,
sizeof(BITMAPINFOHEADER));
//Initialize the fields in the BITMAPINFO structure.
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = bmp.bmWidth;
pbmi->bmiHeader.biHeight = bmp.bmHeight;
pbmi->bmiHeader.biPlanes = bmp.bmPlanes;
pbmi->bmiHeader.biBitCount = bmp.bmBitsPixel;
if (cClrBits < 24)
pbmi->bmiHeader.biClrUsed = (1 << cClrBits);
//If the bitmap is not compressed, set the BI_RGB flag.
pbmi->bmiHeader.biCompression = BI_RGB;
//Compute the number of bytes in the array of color
//indices and store the result in biSizeImage.
pbmi->bmiHeader.biSizeImage = (pbmi->bmiHeader.biWidth + 7) / 8
* pbmi->bmiHeader.biHeight * cClrBits;
//Set biClrImportant to 0, indicating that all of the
//device colors are important.
pbmi->bmiHeader.biClrImportant = 0;
HANDLE hf;                  //file handle
BITMAPFILEHEADER hdr;       //bitmap file-header
PBITMAPINFOHEADER pbih;     //bitmap info-header
LPBYTE lpBits;              //memory pointer
DWORD dwTotal;              //total count of bytes
DWORD cb;                   //incremental count of bytes
BYTE *hp;                   //byte pointer
DWORD dwTmp;
pbih = (PBITMAPINFOHEADER) pbmi;
lpBits = (LPBYTE) GlobalAlloc(GMEM_FIXED, pbih->biSizeImage);
if (!lpBits) return 0;
//Retrieve the color table (RGBQUAD array) and the bits
//(array of palette indices) from the DIB.
if (!GetDIBits(hdcMem, hbmScr, 0, (WORD) pbih->biHeight, lpBits, pbmi, DIB_RGB_COLORS)) return 0;
//Create the .BMP file.
hf = CreateFile(szFile,
GENERIC_READ | GENERIC_WRITE,
(DWORD) 0,
NULL,
CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL,
(HANDLE) NULL);
if (hf == INVALID_HANDLE_VALUE) return 0;
hdr.bfType = 0x4d42;        //0x42 = "B" 0x4d = "M"
//Compute the size of the entire file.
hdr.bfSize = (DWORD) (sizeof(BITMAPFILEHEADER) +
pbih->biSize + pbih->biClrUsed *
sizeof(RGBQUAD) + pbih->biSizeImage);
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
//Compute the offset to the array of color indices.
hdr.bfOffBits = (DWORD) sizeof(BITMAPFILEHEADER) +
pbih->biSize + pbih->biClrUsed *
sizeof (RGBQUAD);
//Copy the BITMAPFILEHEADER into the .BMP file.
if (!WriteFile(hf, (LPVOID) &hdr, sizeof(BITMAPFILEHEADER), (LPDWORD) &dwTmp, NULL)) return 0;
//Copy the BITMAPINFOHEADER and RGBQUAD array into the file.
if (!WriteFile(hf, (LPVOID) pbih, sizeof(BITMAPINFOHEADER)
+ pbih->biClrUsed * sizeof (RGBQUAD),
(LPDWORD) &dwTmp, NULL))
return 0;
//Copy the array of color indices into the .BMP file.
dwTotal = cb = pbih->biSizeImage;
hp = lpBits;
if (!WriteFile(hf, (LPSTR) hp, (int) cb, (LPDWORD) &dwTmp, NULL)) return 0;
//Close the .BMP file.
if (!CloseHandle(hf)) return 0;
//Free memory.
GlobalFree((HGLOBAL)lpBits);
ReleaseDC(0, hdcScr);
ReleaseDC(0, hdcMem);
return 1;
} 

OriginalL'auteur Romain Hippeau