BMP 24 32 显示 翻转

原文地址：http://blog.csdn.net/hxmcnu/article/details/12359731

 参数定义

private:
	BYTE * BmpBuffer;//24BMP位图数据
	long bmpWidth ;
	long bmpHeight;
	BYTE *p32BitBuf;//32位BMP数据
	int totalSize;//数据大小
	int bytes_per_line;//每行的字节数
	int m_nAlpha1;//32位BMP中alpha值，用于调节通明度
public:
	bool Open24BMP();
	bool Show24BMP();
	bool Show32BMP();
	bool Conver24To32(int m_nAlpha1);
	int Set32BitBmpAlpha(int nAlpha);

相关功能实现：

//读取一张24bit的BMP保存到个BYTE buffer里面：
bool CConverBMPDlg::Open24BMP()
{
	// 
	BYTE *pBmpBuf;
	CFileDialog GetFile(TRUE,NULL,NULL,OFN_FILEMUSTEXIST,_T("BMP(*.bmp)|*.bmp|All Files(*.*)|*.*"));
	if(IDOK == GetFile.DoModal())
	{
		CString strFilePath = GetFile.GetPathName();
		FILE *fp=NULL; 
		int ret = fopen_s(&fp,strFilePath,"rb"); 
		if(fp==0)    
		{ 
			return false; 
		} 
		BITMAPFILEHEADER fileheader={0}; 
		fread(&fileheader,sizeof(fileheader),1,fp); 
		if(fileheader.bfType!=0x4D42) 
		{ 
			fclose(fp); 
			return false ; 
		} 
		BITMAPINFOHEADER head; 
		fread(&head,sizeof(BITMAPINFOHEADER),1,fp);  
		bmpWidth = head.biWidth; 
		bmpHeight = head.biHeight; 
		WORD biBitCount = head.biBitCount; 
		if(biBitCount != 24) 
		{ 
			::AfxMessageBox(_T("choose a 24 bit bmp")); 
			fclose(fp); 
			return false ; 
		} 
		bytes_per_line = (bmpWidth * biBitCount/8+3)/4*4;
		totalSize = bytes_per_line*bmpHeight; 
		pBmpBuf = new BYTE[totalSize]; // 24 bit buf
		size_t size = 0; 
		while(true) 
		{ 
			int iret = fread(&pBmpBuf[size],1,1,fp); 
			if(iret == 0) 
				break; 
			size = size + iret; 
		} 
		fclose(fp); 
	}

 
	/
	//上面读出来的是翻转的，下面正过来：
	//flip
	BYTE *buffer; 
	int index;
	BmpBuffer = new BYTE[totalSize];//24位BMP Buffer
	buffer = new BYTE[totalSize];//temp buf to flip 24bit bmp map
	memcpy(buffer,pBmpBuf,totalSize);
	for (index=0; index < bmpHeight; index++)
		memcpy(&BmpBuffer[((bmpHeight-1) - index)*bytes_per_line],
		&buffer[index*bytes_per_line], bytes_per_line);
	delete[] buffer;
	buffer = NULL;
	return true;
}
bool CConverBMPDlg::Show24BMP()
{
	//显示一下:
	show 24bit
	int i,j; 
	CClientDC dc(this); 
	int pitch = bmpWidth % 4; 
	for(i=0;i

void RGB32Rotate180(BYTE *des,BYTE *src,int width,int height) 
{ 

    if ((!des)||(!src)) 
    { 
        return; 
    } 
       
    int n = 0; 
    int linesize = width*4;
		for (int index=0; index < height; index++)
			memcpy(&des[((height-1) - index)*linesize],&src[index*linesize], linesize);
}