单色位图旋转90度

 

bool RotateBmp(const char* szFileName)
{
	// 读取文件头
	BITMAPFILEHEADER	strBmpHead;
	BITMAPINFOHEADER	strBmpBitmap;
	RGBQUAD bmprgb1 = {0,0,0,0};
	RGBQUAD bmprgb2 = {255,255,255,0};
	byte	*pAllContent=NULL;
	
	memset((void*)&strBmpHead,  0, sizeof(strBmpHead));
	memset((void*)&strBmpBitmap,0, sizeof(strBmpBitmap));
	
	CFile openFile;
	char filehead[sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)];
	
	//char conent_information[40];
	if(!openFile.Open(szFileName, CFile::modeRead))
	{
		return false;
	}
	
	if(openFile.Read(filehead, sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER)) != sizeof(BITMAPFILEHEADER)+sizeof(BITMAPINFOHEADER))
	{
		//this->MessageBox("读取数据失败！");
		openFile.Close();
		return false;
	}
	
	memcpy((void*)&strBmpHead, filehead, sizeof(BITMAPFILEHEADER));
	memcpy((void*)&strBmpBitmap, filehead+sizeof(BITMAPFILEHEADER),sizeof(BITMAPINFOHEADER));
	
	if(0x424d == strBmpHead.bfType)
	{
		//this->MessageBox("文件格式错误！");
		openFile.Close();
		return false;	
	}

	if (1 != strBmpBitmap.biBitCount)
	{
		openFile.Close();
		return false;
	}

	if (openFile.Read((void*)&bmprgb1, sizeof(bmprgb1)) != sizeof(bmprgb1))
	{
		openFile.Close();
		return false;
	}
	if (openFile.Read((void*)&bmprgb2, sizeof(bmprgb2)) != sizeof(bmprgb2))
	{
		openFile.Close();
		return false;
	}

	
	DWORD allLength = strBmpHead.bfSize - strBmpHead.bfOffBits;
	openFile.Seek(strBmpHead.bfOffBits, CFile::begin);
	
	
	//将数据进行分析，数据时正确读出来。
	pAllContent = new byte[sizeof(byte)*allLength];
	if(NULL == pAllContent)
	{
	//	MessageBox("开辟空间失败！");
		openFile.Close();
		return false;
	}
	
	DWORD length = openFile.Read(pAllContent, allLength);
	if(allLength != length)
	{
		//this->MessageBox("文件长度错误，读取数据失败！");
		openFile.Close();
		return false;
	}
	openFile.Close();

	//分配空间
	LONG nNewWidth = strBmpBitmap.biHeight;
    LONG nNewHeight = strBmpBitmap.biWidth ;
	LONG nNewBMPRowByte = ((nNewWidth*strBmpBitmap.biBitCount + 31)/8)/4*4;		//一行占得字节数


	//将数据进行分析，数据时正确读出来。
	byte *pNewAllContent = new byte[nNewHeight * nNewBMPRowByte + 1];
	if(NULL == pNewAllContent)
	{
		return false;
	}
	memset(pNewAllContent, 0, nNewHeight * nNewBMPRowByte + 1);

 	LONG nBmpRowByte = ((strBmpBitmap.biWidth*strBmpBitmap.biBitCount + 31)/8)/4*4;	 

	// 转存数据
	for (int row = 0 ; row < strBmpBitmap.biHeight; row ++ )
	{
		for(int col = 0; col < strBmpBitmap.biWidth; col ++)
		{
			if (pAllContent[row * nBmpRowByte + col / 8] & (0x01 << (7 - col % 8)))
			{
				pNewAllContent[(nNewHeight - col - 1) * nNewBMPRowByte + row / 8] |= 0x01 << (7 - row % 8);
			}	
		}
	}

	if(!openFile.Open(szFileName, CFile::modeCreate | CFile::modeWrite))
	{
		return false;
	}
	strBmpBitmap.biWidth = nNewWidth;
	strBmpBitmap.biHeight = nNewHeight;

	openFile.Write((void*)&strBmpHead, sizeof(strBmpHead));
	openFile.Write((void*)&strBmpBitmap, sizeof(strBmpBitmap));
	openFile.Write((void*)&bmprgb1, sizeof(bmprgb1));
	openFile.Write((void*)&bmprgb2, sizeof(bmprgb2));
	openFile.Write(pNewAllContent, nNewHeight * nNewBMPRowByte);

	openFile.Close();

	delete []pAllContent;
	pAllContent = NULL;
	delete []pNewAllContent;
	pNewAllContent = NULL;
	return true;
}

注意 

1、前原图的行、列 与新图的行列反转，位运算是也要对应。