dibapi.cpp

vc++实现简单图像编辑器。。。。。。。。。

/*******************************************
*   Function Name:                                 
*                                                   
*   GetSystemPalette()                                  
*                                                 
*   Parameters :                                  
*                                                  
*   HDC hDC           -handle of device context to display
*                      palette
*	                                       
*   Return Value:                                 
*                                                   
*   HPALETTE -destination palette handle                  
*                                                   
*   Description:                                  
*                                                   
*   This function  returns a handle to a palette which 
*   represents the system palette .The system RGB values
*   are copied into our logical palette using the Get-
*   systemPaletteEntries function
//******************************************************/

HPALETTE GetSystemPalette(HDC hDC)
{
	static HPALETTE hPal=NULL;// handle of the palette
	HANDLE hLogPal;//handle of a logical palette
	LPLOGPALETTE lpLogPal;//pointer to a logical palette
	int nColors;// number of colors

	//find out how many palette entries we want

	nColors=PalEntriesOnDevice(hDC);
	//Number of the palette entries

	//Allocate a room for the palette and lock it
	hLogPal=::GlobalAlloc(GHND,
		                  sizeof(LOGPALETTE)+nColors*sizeof(PALETTEENTRY));

	// if we didn't get a logical palette ,return null
	if (!hLogPal)
		return NULL;
	//get a pointer to the logical palette

	lpLogPal =(LPLOGPALETTE)::GlobalLock (hLogPal);

	//set some important fields
	 lpLogPal->palVersion =PALVERSION;
	 lpLogPal->palNumEntries =nColors;
     //copy the current system palette into our logical palette
	 GetSystemPaletteEntries (hDC,0,nColors,
		                        (LPPALETTEENTRY)(lpLogPal->palPalEntry ));

	 //Go ahead and create the palette. once it's create
	 // we no longer need the LOGPALETTE ,so free it

	 hPal=::CreatePalette (lpLogPal);

	 //clean up

	 GlobalUnlock(hLogPal);
	 GlobalFree (hLogPal);
	 return hPal;               

}
/********************************************************
*   Function Name:                                 
*                                                   
*   CreateDIBPalette()                                  
*                                                 
*   Parameters :                                  
*                                                  
*   LPBYTE lpbi       -specifies the DIB
*	                                       
*   Return Value:                                 
*                                                   
*   HPALETTE -destination palette handle                  
*                                                   
*   Description:                                  
*                                                   
*   This function  Create a Palette from the DIB color table 
/************************************************************/

HPALETTE CreateDIBPalette(LPBYTE lpbi)
{

	LPLOGPALETTE lpPal;//pointer to a logical palette
	HANDLE hLogPal;// handle to a logical palette
	HPALETTE hPal=NULL; // handle to palette
	LPBITMAPINFO lpbmi;//pointer to bitmapinfo structure
	int i,wNumColors;//loop index,number of colors in color table

	// if handle to DIB is invalid,return NULL
	if(!lpbi)
	{
	  return NULL;
	}

	//get pointer to BITMAPINFO(WIN 30)

	lpbmi=(LPBITMAPINFO)lpbi;


	//get the number of colors in the DIB
	wNumColors=DIBNumColors(lpbi);

	//is this a win3.0 DIB?

	
	if(wNumColors)
	{
		//allocates memory block for logical palette
		hLogPal=GlobalAlloc(GHND,sizeof(LOGPALETTE)+
			                sizeof(PALETTEENTRY)*wNumColors);
		//if not enough memory, clean up and return NULL

		if(!hLogPal)
			return NULL;
		//lock memory block and get pointer to it

		lpPal=(LPLOGPALETTE)GlobalLock(hLogPal);
		
		//Set version and number of palette entries

		lpPal->palVersion =PALVERSION;
		lpPal->palNumEntries =wNumColors;

		//store RGB triples(if(win 3.0DIB) or RGB quads(if OS/2DIB)
		//into palette

		for(i=0;i<wNumColors;i++)
		{
				lpPal->palPalEntry [i].peRed =
				lpbmi->bmiColors[i].rgbRed;
				lpPal->palPalEntry [i].peGreen =
					lpbmi->bmiColors[i].rgbGreen;
				lpPal->palPalEntry [i].peBlue =
					lpbmi->bmiColors[i].rgbBlue;
				lpPal->palPalEntry [i].peFlags =0;
		}
		
		
		//create the palette and get handle to it
		hPal=::CreatePalette(lpPal);

		//if error getting handle to palette ,clean up and return

		if(!hPal)
		{
			GlobalUnlock(hLogPal);
			GlobalFree(hLogPal);
			return NULL;
		}

		//clean up

			GlobalUnlock(hLogPal);
			GlobalFree(hLogPal);
	}
	
	return hPal;
}
/********************************************************
*   Function Name:                                 
*                                                   
*   CreateDIBPalette()                                  
*                                                 
*   Parameters :                                  
*                                                  
*   HDIB       -specifies the DIB
*	                                       
*   Return Value:                                 
*                                                   
*   HPALETTE -destination palette handle                  
*                                                   
*   Description:                                  
*                                                   
*   This function  Create a Palette from the DIB color table 
/************************************************************/
//根据图像数据块,创建调色板数据块
HPALETTE CreateDIBPalette(HDIB hDIB)
{
	//锁定位图信息头
	LPBITMAPINFOHEADER lpbi;
	lpbi=(LPBITMAPINFOHEADER)GlobalLock(hDIB);
    //VC自带的逻辑调色板数据结构
	LPLOGPALETTE lpPal;//pointer to a logical palette
	HANDLE hLogPal;// handle to a logical palette
	HPALETTE hPal=NULL; // handle to palette
	//位图信息数据结构指针
	LPBITMAPINFO lpbmi;//pointer to bitmapinfo structure
	int i,wNumColors;//loop index,number of colors in color table

	// if handle to DIB is invalid,return NULL
	if(!lpbi)
	{
	  return NULL;
	}

	//get pointer to BITMAPINFO(WIN 30)
    //锁定位图信息(包括位图信息头和颜色表)
	lpbmi=(LPBITMAPINFO)lpbi;
	//get the number of colors in the DIB
	//计算当前图像数据块的颜色数目
	wNumColors=DIBNumColors(lpbi);
	//根据颜色数目,计算颜色表的大小,创建颜色表内存块
	if(wNumColors)
	{
		//allocates memory block for logical palette
		//分配内存
		int nPal=sizeof(PALETTEENTRY);
		int nPalSize=nPal*wNumColors;
		int nLogPal=sizeof(LOGPALETTE);
		hLogPal=GlobalAlloc(GHND,nLogPal+nPalSize);
		//if not enough memory, clean up and return NULL

		if(!hLogPal)
			return NULL;
		//lock memory block and get pointer to it
        //锁定调色板数据块内存
		lpPal=(LPLOGPALETTE)GlobalLock(hLogPal);
		//Set version and number of palette entries
		//设置相应的字段值
		lpPal->palVersion =PALVERSION;
		lpPal->palNumEntries =wNumColors;

		//store RGB triples(if(win 3.0DIB) or RGB quads(if OS/2DIB)
		//into palette
        //将图像中读出的颜色表信息放入调色板数据结构中
		for(i=0;i<wNumColors;i++)
		{
			lpPal->palPalEntry [i].peRed =
				lpbmi->bmiColors[i].rgbRed;
            int n=lpbmi->bmiColors[i].rgbRed;
			lpPal->palPalEntry [i].peGreen =
				lpbmi->bmiColors[i].rgbGreen;
			lpPal->palPalEntry [i].peBlue =
				lpbmi->bmiColors[i].rgbBlue;
			lpPal->palPalEntry [i].peFlags =0;
		}
		//create the palette and get handle to it
		//根据调色板指针返回调色板内存块句柄(WinAPI函数)
		hPal=::CreatePalette(lpPal);

		//if error getting handle to palette ,clean up and return

		if(!hPal)
		{
			GlobalUnlock(hLogPal);
			GlobalFree(hLogPal);
			return NULL;
		}

		//clean up
        //释放逻辑调色板内存
		//(以后使用Windows的调色板句柄控制调色板)
		GlobalUnlock(hLogPal);
		GlobalFree(hLogPal);
	}
	
	GlobalUnlock(hDIB);
	return hPal;

}
/*************************************************************
*   Function Name:                                 
*                                                   
*   DIBToDIBSection()                                  
*                                                 
*   Parameters :                                  
*                                                  
*   LPBYTE lpDIB       -pointer to DIB data buffer
*	                                       
*   Return Value:                                 
*                                                   
*   HBITMAP - handle  of DIBSECTION or NULL for failure                
*                                                   
*   Description:                                  
*                                                   
*   This function create DIBSECTION from DIB
*
**************************************************************/
HBITMAP DIBToDIBSection(LPBYTE lpDIB)
{
	LPBYTE lpSourceBits;
	HDC hDC=NULL,hSourceDC;
	HBITMAP hSourceBitmap,hOldSourceBitmap;
	DWORD dwSourceBitSize;
	LPBITMAPINFO lpSrcDIB=(LPBITMAPINFO)lpDIB;
	if(!lpSrcDIB)
		return NULL;
	//go to use DIBSections and BitBlt() to do the conversion,
	hDC=GetDC(NULL);
	hSourceBitmap=CreateDIBSection(hDC,lpSrcDIB,DIB_RGB_COLORS,
		            (void**)&lpSourceBits,NULL,0);
	hSourceDC=CreateCompatibleDC(hDC);
	//flip the bits on the source DIBSection to match the source DIB
	dwSourceBitSize=lpSrcDIB->bmiHeader .biHeight *
		      BytesPerLine((LPBYTE)&(lpSrcDIB->bmiHeader ));
	memcpy(lpSourceBits,FindDIBBits((LPBYTE)lpSrcDIB),dwSourceBitSize);
	
	//select DIBSections int DCs
    hOldSourceBitmap=(HBITMAP)SelectObject(hSourceDC,hSourceBitmap);
	//set the color tables for the DIBSections
	if(lpSrcDIB->bmiHeader .biBitCount <=8)
		SetDIBColorTable(hSourceDC,0,
		     1<<lpSrcDIB->bmiHeader .biBitCount ,
			 lpSrcDIB->bmiColors );
	//clean up and delete the DCs
	SelectObject(hSourceDC,hOldSourceBitmap);
	DeleteDC(hSourceDC);
	ReleaseDC(NULL,hDC);
	//Flush the GDI batch,so we can play with the bits
	GdiFlush();
	return hSourceBitmap;


}
/*************************************************************
*   Function Name:                                 
*                                                   
*   DIBToDIBSection()                                  
*                                                 
*   Parameters :                                  
*                                                  
*   HDIB hDIB       -pointer to DIB data buffer
*	                                       
*   Return Value:                                 
*                                                   
*   HBITMAP - handle  of DIBSECTION or NULL for failure                
*                                                   
*   Description:                                  
*                                                   
*   This function create DIBSECTION from DIB
*
**************************************************************/
HBITMAP DIBToDIBSection(HDIB hDIB)
{
	//锁定位图信息头
	LPBITMAPINFOHEADER lpDIB;
	lpDIB=(LPBITMAPINFOHEADER)GlobalLock(hDIB);

	LPBYTE lpSourceBits;
	//设备上下文句柄
	HDC hDC=NULL,hSourceDC;
	//位图句柄
	HBITMAP hSourceBitmap,hOldSourceBitmap;
	DWORD dwSourceBitSize;
	//位图信息数据结构
	LPBITMAPINFO lpSrcDIB=(LPBITMAPINFO)lpDIB;
	if(!lpSrcDIB)
		return NULL;
	//go to use DIBSections and BitBlt() to do the conversion,
	//获得当前的设备上下文
	hDC=GetDC(NULL);
	//创建位图数据句柄,调用WinAPI函数
	hSourceBitmap=CreateDIBSection(hDC,lpSrcDIB,DIB_RGB_COLORS,
		            (void**)&lpSourceBits,NULL,0);
	//创建兼容的设备上下文备用
	hSourceDC=CreateCompatibleDC(hDC);
	//flip the bits on the source DIBSection to match the source DIB
	//计算位图数据需要的字节数
	dwSourceBitSize=lpSrcDIB->bmiHeader .biHeight *
		      BytesPerLine((LPBYTE)&(lpSrcDIB->bmiHeader ));

    //将实际位图数据复制到lpSourceBits中
	memcpy(lpSourceBits,FindDIBBits((LPBYTE)lpSrcDIB),dwSourceBitSize);