Decode into a File - Example 3

The next example below demonstrates the decoding into a file:

int CALLBACK CopyLineToFile(LPSTR lpLineBuff, int nLine, LONG lParam)

{

                int nBytesWritten, nBytesPerLine, nFile;

                // Retrieves some variables from the user defined parameter.

                nBytesPerLine = (int) HIWORD(lParam);

                nFile = (int) LOWORD(lParam);

                // Writes data into file.

                nBytesWritten = _lwrite(nFileHndl,lpLineBuff,nBytesPerLine);

                // Returns the error status.

                return((nBytesPerLine == nBytesWritten) ? TOK : TFILEIOERROR);

}

The file handle and the bytes per line value was passed to DecodeTiffImage() as the lParam parameter using the predefined Windows macro:

                lParam = MAKELONG(nFile,nBytesPerLine);

Assuming integer arithmetic the bytes per line parameter can be calculated as:

                nBytesPerLine = (BmIH.biBitCount * BmIH.biWidth + 31) / 8

...where BmIH is a BITMAPINFOHEADER structure. Each line is aligned at a LONG boundary according to the rules of bitmap files.