bitmapex.cpp

包括了一些VC编程实例

	DWORD m_dwAlignedWidthBytes = (bmp.bmWidthBytes & ~0x3) + (!!(bmp.bmWidthBytes & 0x3) << 2);
	// DIB image is flipped that's why we scan it from the last line
	LPBYTE	pColor = pBits + (bih.biHeight - 1) * m_dwAlignedWidthBytes;
	DWORD	dwLineBackLen = m_dwAlignedWidthBytes + bih.biWidth * Bpp;	// offset of previous scan line
													// (after processing of current)
	DWORD	dwRectsCount = bih.biHeight;			// number of rects in allocated buffer
	INT		i, j;									// current position in mask image
	INT		first = 0;								// left position of current scan line
													// where mask was found
	bool	wasfirst = false;						// set when mask has been found in current scan line
	bool	ismask;									// set when current color is mask color

	// allocate memory for region data
	// region data here is set of regions that are rectangles with height 1 pixel (scan line)
	// that's why first allocation is <bm.biHeight> RECTs - number of scan lines in image
	RGNDATAHEADER* pRgnData = 
		(RGNDATAHEADER*)new BYTE[ RGNDATAHEADER_SIZE + dwRectsCount * sizeof(RECT) ];
	// get pointer to RECT table
	LPRECT pRects = (LPRECT)((LPBYTE)pRgnData + RGNDATAHEADER_SIZE);
	// zero region data header memory (header  part only)
	memset( pRgnData, 0, RGNDATAHEADER_SIZE + dwRectsCount * sizeof(RECT) );
	// fill it by default
	pRgnData->dwSize	= RGNDATAHEADER_SIZE;
	pRgnData->iType		= RDH_RECTANGLES;

	for ( i = 0; i < bih.biHeight; i++ )
	{
		for ( j = 0; j < bih.biWidth; j++ )
		{
			// get color
			switch ( bih.biBitCount )
			{
			case 8:
				ismask = (clr_tbl[ *pColor ] != color);
				break;
			case 16:
				ismask = (*(LPWORD)pColor != (WORD)color);
				break;
			case 24:
				ismask = ((*(LPDWORD)pColor & 0x00ffffff) != color);
				break;
			case 32:
				ismask = (*(LPDWORD)pColor != color);
			}
			// shift pointer to next color
			pColor += Bpp;
			// place part of scan line as RECT region if transparent color found after mask color or
			// mask color found at the end of mask image
			if ( wasfirst )
			{
				if ( !ismask )
				{
					// save current RECT
					pRects[ pRgnData->nCount++ ] = CRect( first, i, j, i + 1 );
					// if buffer full reallocate it with more room
					if ( pRgnData->nCount >= dwRectsCount )
					{
						dwRectsCount += ADD_RECTS_COUNT;
						// allocate new buffer
						LPBYTE pRgnDataNew = new BYTE[ RGNDATAHEADER_SIZE + dwRectsCount * sizeof(RECT) ];
						// copy current region data to it
						memcpy( pRgnDataNew, pRgnData, RGNDATAHEADER_SIZE + pRgnData->nCount * sizeof(RECT) );
						// delte old region data buffer
						delete pRgnData;
						// set pointer to new regiondata buffer to current
						pRgnData = (RGNDATAHEADER*)pRgnDataNew;
						// correct pointer to RECT table
						pRects = (LPRECT)((LPBYTE)pRgnData + RGNDATAHEADER_SIZE);
					}
					wasfirst = false;
				}
			}
			else if ( ismask )		// set wasfirst when mask is found
			{
				first = j;
				wasfirst = true;
			}
		}

		if ( wasfirst && ismask )
		{
			// save current RECT
			pRects[ pRgnData->nCount++ ] = CRect( first, i, j, i + 1 );
			// if buffer full reallocate it with more room
			if ( pRgnData->nCount >= dwRectsCount )
			{
				dwRectsCount += ADD_RECTS_COUNT;
				// allocate new buffer
				LPBYTE pRgnDataNew = new BYTE[ RGNDATAHEADER_SIZE + dwRectsCount * sizeof(RECT) ];
				// copy current region data to it
				memcpy( pRgnDataNew, pRgnData, RGNDATAHEADER_SIZE + pRgnData->nCount * sizeof(RECT) );
				// delte old region data buffer
				delete pRgnData;
				// set pointer to new regiondata buffer to current
				pRgnData = (RGNDATAHEADER*)pRgnDataNew;
				// correct pointer to RECT table
				pRects = (LPRECT)((LPBYTE)pRgnData + RGNDATAHEADER_SIZE);
			}
			wasfirst = false;
		}

		pColor -= dwLineBackLen;
	}
	// release image data
	delete pBits;
	delete bi;

	// create region
	HRGN hRgn = ExtCreateRegion( NULL, RGNDATAHEADER_SIZE + pRgnData->nCount * sizeof(RECT), (LPRGNDATA)pRgnData );
	// release region data
	delete pRgnData;

	return hRgn;
}

BOOL CBitmapEx::LoadImage(UINT uIDRes, LPCTSTR szResourceType, HMODULE hInst, COLORREF crBack)
{
	ASSERT(m_hObject == NULL);      // only attach once, detach on destroy

	if (m_hObject != NULL)
		return FALSE;

	BYTE*	pBuff = NULL;
	int		nSize = 0;
	BOOL bResult = FALSE;

	// first call is to get buffer size
	if (GetResource(MAKEINTRESOURCE(uIDRes), szResourceType, hInst, 0, nSize))
	{
		if (nSize > 0)
		{
			pBuff = new BYTE[nSize];
			
			// this loads it
			if (GetResource(MAKEINTRESOURCE(uIDRes), szResourceType, hInst, pBuff, nSize))
			{
				IPicture* pPicture = LoadFromBuffer(pBuff, nSize);

				if (pPicture)
				{
					bResult = Attach(pPicture, crBack);
					pPicture->Release();
				}
			}
			
			delete [] pBuff;
		}
	}

	return bResult;
}

BOOL CBitmapEx::LoadImage(LPCTSTR szImagePath, COLORREF crBack)
{
	ASSERT(m_hObject == NULL);      // only attach once, detach on destroy

	if (m_hObject != NULL)
		return FALSE;

	BOOL bResult = FALSE;
	CFile			cFile;
	CFileException	e;
	
	if (cFile.Open(szImagePath, CFile::modeRead | CFile::typeBinary, &e))
	{
		int nSize = cFile.GetLength();

		BYTE* pBuff = new BYTE[nSize];
		
		if (cFile.Read(pBuff, nSize) > 0)
		{
			IPicture* pPicture = LoadFromBuffer(pBuff, nSize);
			
			if (pPicture)
			{
				bResult = Attach(pPicture, crBack);
				pPicture->Release();
			}
		}
		
		delete [] pBuff;
	}

	return bResult;
}

IPicture* CBitmapEx::LoadFromBuffer(BYTE* pBuff, int nSize)
{
	bool bResult = false;

	HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE, nSize);
	void* pData = GlobalLock(hGlobal);
	memcpy(pData, pBuff, nSize);
	GlobalUnlock(hGlobal);

	IStream* pStream = NULL;
	IPicture* pPicture = NULL;

	if (CreateStreamOnHGlobal(hGlobal, TRUE, &pStream) == S_OK)
	{
		HRESULT hr = OleLoadPicture(pStream, nSize, FALSE, IID_IPicture, (LPVOID *)&pPicture);
		pStream->Release();
	}

	return pPicture; // caller releases
}

BOOL CBitmapEx::GetResource(LPCTSTR lpName, LPCTSTR lpType, HMODULE hInst, void* pResource, int& nBufSize)
{ 
	HRSRC		hResInfo;
	HANDLE		hRes;
	LPSTR		lpRes	= NULL; 
	int			nLen	= 0;
	bool		bResult	= FALSE;

	// Find the resource
	hResInfo = FindResource(hInst, lpName, lpType);

	if (hResInfo == NULL) 
		return false;

	// Load the resource
	hRes = LoadResource(hInst, hResInfo);

	if (hRes == NULL) 
		return false;

	// Lock the resource
	lpRes = (char*)LockResource(hRes);

	if (lpRes != NULL)
	{ 
		if (pResource == NULL)
		{
			nBufSize = SizeofResource(hInst, hResInfo);
			bResult = true;
		}
		else
		{
			if (nBufSize >= (int)SizeofResource(hInst, hResInfo))
			{
				memcpy(pResource, lpRes, nBufSize);
				bResult = true;
			}
		} 

		UnlockResource(hRes);  
	}

	// Free the resource
	FreeResource(hRes);

	return bResult;
}
BOOL CBitmapEx::Attach(IPicture* pPicture, COLORREF crBack)
{
	ASSERT(m_hObject == NULL);      // only attach once, detach on destroy

	if (m_hObject != NULL)
		return FALSE;

	ASSERT(pPicture);

	if (!pPicture)
		return FALSE;

	BOOL bResult = FALSE;

	CDC dcMem;
	CDC* pDC = CWnd::GetDesktopWindow()->GetDC();

	if (dcMem.CreateCompatibleDC(pDC))
	{
		long hmWidth;
		long hmHeight;

		pPicture->get_Width(&hmWidth);
		pPicture->get_Height(&hmHeight);
		
		int nWidth	= MulDiv(hmWidth,	pDC->GetDeviceCaps(LOGPIXELSX), HIMETRIC_INCH);
		int nHeight	= MulDiv(hmHeight,	pDC->GetDeviceCaps(LOGPIXELSY), HIMETRIC_INCH);

		CBitmap bmMem;

		if (bmMem.CreateCompatibleBitmap(pDC, nWidth, nHeight))
		{
			CBitmap* pOldBM = dcMem.SelectObject(&bmMem);

			if (crBack != -1)
				dcMem.FillSolidRect(0, 0, nWidth, nHeight, crBack);
			
			HRESULT hr = pPicture->Render(dcMem, 0, 0, nWidth, nHeight, 0, hmHeight, hmWidth, -hmHeight, NULL);
			dcMem.SelectObject(pOldBM);

			if (hr == S_OK)
				bResult = CBitmap::Attach(bmMem.Detach());
		}
	}

	CWnd::GetDesktopWindow()->ReleaseDC(pDC);

	return bResult;
}