ReadFile(hSourceFile,pSource,dwSourceSize,&dwTemp,NULL);
BITMAPFILEHEADER *pSourceFileHeader=(BITMAPFILEHEADER*)pSource;
BITMAPINFOHEADER
*pSourceInfoHeader=(BITMAPINFOHEADER*)(pSource+sizeof(BITMAPFILEHEADER));
//不是 BMP 文件或者不是 24 位真彩色
if(pSourceFileHeader->bfType!=0x4d42||pSourceInfoHeader->biBitCount!=24)
{
CloseHandle(hSourceFile);
VirtualFree(pSource,NULL,MEM_RELEASE);
return FALSE;
}
CloseHandle(hSourceFile);
LONG nWidth=pSourceInfoHeader->biWidth;
LONG nHeight=pSourceInfoHeader->biHeight;
LONG nSourceWidth=nWidth*3;if(nSourceWidth%4) nSourceWidth=(nSourceWidth/4+1)*4;
LONG nTargetWidth=nWidth;if(nTargetWidth%4) nTargetWidth=(nTargetWidth/4+1)*4;
dwTargetSize=sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)+sizeof(RGBQUAD)*256
+nHeight*nTargetWidth;
pTarget=(PBYTE)VirtualAlloc(NULL,dwTargetSize,MEM_COMMIT,PAGE_READWRITE);
memset(pTarget,0,dwTargetSize);
if(pTarget==NULL)
{
VirtualFree(pTarget,NULL,MEM_RELEASE);
return FALSE;
}
BITMAPFILEHEADER *pTargetFileHeader=(BITMAPFILEHEADER *)pTarget;
BITMAPINFOHEADER *pTargetInfoHeader =
(BITMAPINFOHEADER *)(pTarget+sizeof(BITMAPFILEHEADER));
pTargetFileHeader->bfType=pSourceFileHeader->bfType;
pTargetFileHeader->bfSize=dwTargetSize;
pTargetFileHeader->bfReserved1=0;
pTargetFileHeader->bfReserved2=0;
pTargetFileHeader->bfOffBits=sizeof(BITMAPFILEHEADER)
+sizeof(BITMAPINFOHEADER)+sizeof(RGBQUAD)*256;