pictureex.cpp

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	if (m_hDispMemDC)
	{
		SelectObject(m_hDispMemDC,m_hDispOldBM);
		::DeleteDC(m_hDispMemDC);
		::DeleteObject(m_hDispMemBM);
		m_hDispMemDC  = NULL;
		m_hDispMemBM = NULL;
	};

	SetRect(&m_PaintRect,0,0,0,0);
	m_pGIFLSDescriptor = NULL;
	m_pGIFHeader	   = NULL;
	m_pRawData		   = NULL;
	m_hThread		   = NULL;
	m_bIsInitialized   = FALSE;
	m_bExitThread	   = FALSE;
	m_bIsGIF		   = FALSE;
	m_clrBackground    = RGB(255,255,255); // white by default
	m_nGlobalCTSize	   = 0;
	m_nCurrOffset	   = 0;
	m_nCurrFrame	   = 0;
	m_nDataSize		   = 0;
}

BOOL CPictureEx::Draw()
{
	if (!m_bIsInitialized)
	{
		TRACE(_T("Call one of the CPictureEx::Load() member functions before calling Draw()\n"));
		return FALSE;
	};

	if (IsAnimatedGIF())
	{
	// the picture needs animation
	// we'll start the thread that will handle it for us
	
		unsigned int nDummy;
		m_hThread = (HANDLE) _beginthreadex(NULL,0,_ThreadAnimation,this,
			CREATE_SUSPENDED,&nDummy);
		if (!m_hThread)
		{
			TRACE(_T("Draw: Couldn't start a GIF animation thread\n"));
			return FALSE;
		} 
		else 
			ResumeThread(m_hThread);
	} 
	else
	{
		if (m_pPicture)
		{
			long hmWidth;
			long hmHeight;
			m_pPicture->get_Width(&hmWidth);
			m_pPicture->get_Height(&hmHeight);
			if (m_pPicture->Render(m_hMemDC, 0, 0, m_PictureSize.cx, m_PictureSize.cy, 
				0, hmHeight, hmWidth, -hmHeight, NULL) == S_OK)
			{
				Invalidate(FALSE);
				return TRUE;
			};
		};
	};

	return FALSE;	
}

SIZE CPictureEx::GetSize() const
{
	return m_PictureSize;
}

BOOL CPictureEx::Load(LPCTSTR szFileName)
{
	ASSERT(szFileName);
	
	CFile file;
	HGLOBAL hGlobal;
	DWORD dwSize;

	if (!file.Open(szFileName,
				CFile::modeRead | 
				CFile::shareDenyWrite) )
	{
		TRACE(_T("Load (file): Error opening file %s\n"),szFileName);
		return FALSE;
	};

	dwSize = file.GetLength();
	hGlobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD,dwSize);
	if (!hGlobal)
	{
		TRACE(_T("Load (file): Error allocating memory\n"));
		return FALSE;
	};
	
	char *pData = reinterpret_cast<char*>(GlobalLock(hGlobal));
	if (!pData)
	{
		TRACE(_T("Load (file): Error locking memory\n"));
		GlobalFree(hGlobal);
		return FALSE;
	};

	TRY
	{
		file.Read(pData,dwSize);
	}
	CATCH(CFileException, e);                                          
	{
		TRACE(_T("Load (file): An exception occured while reading the file %s\n"),
			szFileName);
		GlobalFree(hGlobal);
		e->Delete();
		file.Close();
		return FALSE;
	}
	END_CATCH
	GlobalUnlock(hGlobal);
	file.Close();

	BOOL bRetValue = Load(hGlobal,dwSize);
	GlobalFree(hGlobal);
	return bRetValue;
}

BOOL CPictureEx::Load(LPCTSTR szResourceName, LPCTSTR szResourceType)
{
	ASSERT(szResourceName);
	ASSERT(szResourceType);

	HRSRC hPicture = FindResource(AfxGetResourceHandle(),szResourceName,szResourceType);
	HGLOBAL hResData;
	if (!hPicture || !(hResData = LoadResource(AfxGetResourceHandle(),hPicture)))
	{
		TRACE(_T("Load (resource): Error loading resource %s\n"),szResourceName);
		return FALSE;
	};
	DWORD dwSize = SizeofResource(AfxGetResourceHandle(),hPicture);

	// hResData is not the real HGLOBAL (we can't lock it)
	// let's make it real

	HGLOBAL hGlobal = GlobalAlloc(GMEM_MOVEABLE | GMEM_NODISCARD,dwSize);
	if (!hGlobal)
	{
		TRACE(_T("Load (resource): Error allocating memory\n"));
		FreeResource(hResData);
		return FALSE;
	};
	
	char *pDest = reinterpret_cast<char *> (GlobalLock(hGlobal));
	char *pSrc = reinterpret_cast<char *> (LockResource(hResData));
	if (!pSrc || !pDest)
	{
		TRACE(_T("Load (resource): Error locking memory\n"));
		GlobalFree(hGlobal);
		FreeResource(hResData);
		return FALSE;
	};
	CopyMemory(pDest,pSrc,dwSize);
	FreeResource(hResData);
	GlobalUnlock(hGlobal);

	BOOL bRetValue = Load(hGlobal,dwSize);
	GlobalFree(hGlobal);
	return bRetValue;
}

void CPictureEx::ResetDataPointer()
{
	// skip header and logical screen descriptor
	m_nCurrOffset = 
		sizeof(TGIFHeader)+sizeof(TGIFLSDescriptor)+m_nGlobalCTSize;
}

BOOL CPictureEx::SkipNextGraphicBlock()
{
	if (!m_pRawData) return FALSE;

	// GIF header + LSDescriptor [+ GCT] [+ Control block] + Data

	enum GIFBlockTypes nBlock;

	nBlock = GetNextBlock();

	while ((nBlock != BLOCK_CONTROLEXT) &&
		   (nBlock != BLOCK_IMAGE) &&
		   (nBlock != BLOCK_PLAINTEXT) &&
		   (nBlock != BLOCK_UNKNOWN) &&
		   (nBlock != BLOCK_TRAILER) )
	{
		if (!SkipNextBlock()) return NULL;
		nBlock = GetNextBlock();
	};

	if ((nBlock == BLOCK_UNKNOWN) ||
		(nBlock == BLOCK_TRAILER))
		return FALSE;

	// it's either a control ext.block, an image or a plain text

	if (GetNextBlockLen() <= 0) return FALSE;

	if (nBlock == BLOCK_CONTROLEXT)
	{
		if (!SkipNextBlock()) return FALSE;
		nBlock = GetNextBlock();

		// skip everything until we meet an image block or a plain-text block
		while ((nBlock != BLOCK_IMAGE) &&
			   (nBlock != BLOCK_PLAINTEXT) &&
			   (nBlock != BLOCK_UNKNOWN) &&
			   (nBlock != BLOCK_TRAILER) )
		{
			if (!SkipNextBlock()) return NULL;
			nBlock = GetNextBlock();
		};

		if ((nBlock == BLOCK_UNKNOWN) ||
			(nBlock == BLOCK_TRAILER))
			return FALSE;
	};

	// skip the found data block (image or plain-text)
	if (!SkipNextBlock()) return FALSE;

	return TRUE;
}

UINT CPictureEx::GetSubBlocksLen(UINT nStartingOffset) const
{
	UINT nRet = 0;
	UINT nCurOffset = nStartingOffset;
	
	while (m_pRawData[nCurOffset] != 0)
	{
		nRet += m_pRawData[nCurOffset]+1;
		nCurOffset += m_pRawData[nCurOffset]+1;
	};

	return nRet+1;
}

enum CPictureEx::GIFBlockTypes CPictureEx::GetNextBlock() const
{
	switch(m_pRawData[m_nCurrOffset])
	{
	case 0x21:
	// extension block
		switch(m_pRawData[m_nCurrOffset+1])
		{
		case 0x01:
		// plain text extension
			return BLOCK_PLAINTEXT;
			break;

		case 0xF9:
		// graphic control extension
			return BLOCK_CONTROLEXT;
			break;

		case 0xFE:
		// comment extension
			return BLOCK_COMMEXT;
			break;

		case 0xFF:
		// application extension
			return BLOCK_APPEXT;
			break;
		};
		break;
	
	case 0x3B:
	// trailer
		return BLOCK_TRAILER;
		break;

	case 0x2C:
	// image data
		return BLOCK_IMAGE;
		break;
	};

	return BLOCK_UNKNOWN;
}

BOOL CPictureEx::SkipNextBlock()
{
	if (!m_pRawData) return FALSE;

	int nLen = GetNextBlockLen();
	if ((nLen <= 0) || ((m_nCurrOffset+nLen) > m_nDataSize))
		return FALSE;

	m_nCurrOffset += nLen;
	return TRUE;
}

int CPictureEx::GetNextBlockLen() const
{
	GIFBlockTypes nBlock = GetNextBlock();

	int nTmp;

	switch(nBlock)
	{
	case BLOCK_UNKNOWN:
		return -1;
		break;

	case BLOCK_TRAILER:
		return 1;
		break;

	case BLOCK_APPEXT:
		nTmp = GetSubBlocksLen(m_nCurrOffset+sizeof(TGIFAppExtension));
		if (nTmp > 0)
			return sizeof(TGIFAppExtension)+nTmp;
		break;

	case BLOCK_COMMEXT:
		nTmp = GetSubBlocksLen(m_nCurrOffset+sizeof(TGIFCommentExt));
		if (nTmp > 0)
			return sizeof(TGIFCommentExt)+nTmp;
		break;

	case BLOCK_CONTROLEXT:
		return sizeof(TGIFControlExt);
		break;

	case BLOCK_PLAINTEXT:
		nTmp = GetSubBlocksLen(m_nCurrOffset+sizeof(TGIFPlainTextExt));
		if (nTmp > 0)
			return sizeof(TGIFPlainTextExt)+nTmp;
		break;

	case BLOCK_IMAGE:
		TGIFImageDescriptor *pIDescr = 
			reinterpret_cast<TGIFImageDescriptor *> (&m_pRawData[m_nCurrOffset]);
		int nLCTSize = (int)
			(pIDescr->GetPackedValue(ID_PACKED_LOCALCT)*3*
			(1 << (pIDescr->GetPackedValue(ID_PACKED_LOCALCTSIZE)+1)));

		int nTmp = GetSubBlocksLen(m_nCurrOffset+
			sizeof(TGIFImageDescriptor) + nLCTSize + 1);
		if (nTmp > 0)
			return sizeof(TGIFImageDescriptor) + nLCTSize + 1 + nTmp;
		break;
	};

	return 0;
}

UINT WINAPI CPictureEx::_ThreadAnimation(LPVOID pParam)
{
	ASSERT(pParam);
	CPictureEx *pPic = reinterpret_cast<CPictureEx *> (pParam);

	pPic->m_bIsPlaying = TRUE;
	pPic->ThreadAnimation();
	pPic->m_bIsPlaying = FALSE;

	// this thread has finished its work so we close the handle
	CloseHandle(pPic->m_hThread); 
	// and init the handle to zero (so that Stop() doesn't Wait on it)
	pPic->m_hThread = 0;
	return 0;
}

void CPictureEx::ThreadAnimation()
{
	// first, restore background (for stop/draw support)
	// disposal method #2
	if (m_arrFrames[m_nCurrFrame].m_nDisposal == 2)
	{
		HBRUSH hBrush = CreateSolidBrush(m_clrBackground);
		if (hBrush)
		{
			RECT rect = {
				m_arrFrames[m_nCurrFrame].m_frameOffset.cx,
				m_arrFrames[m_nCurrFrame].m_frameOffset.cy,
				m_arrFrames[m_nCurrFrame].m_frameOffset.cx + m_arrFrames[m_nCurrFrame].m_frameSize.cx,
				m_arrFrames[m_nCurrFrame].m_frameOffset.cy + m_arrFrames[m_nCurrFrame].m_frameSize.cy };
			FillRect(m_hMemDC,&rect,hBrush);
			DeleteObject(hBrush);
		};
	} 
	else
		// disposal method #3
		if (m_hDispMemDC && (m_arrFrames[m_nCurrFrame].m_nDisposal == 3) )
		{
			// put it back
			BitBlt(m_hMemDC,
				m_arrFrames[m_nCurrFrame].m_frameOffset.cx,
				m_arrFrames[m_nCurrFrame].m_frameOffset.cy,
				m_arrFrames[m_nCurrFrame].m_frameSize.cx,
				m_arrFrames[m_nCurrFrame].m_frameSize.cy,
				m_hDispMemDC,0,0, SRCCOPY);
			// init variables
			SelectObject(m_hDispMemDC,m_hDispOldBM);
			DeleteDC(m_hDispMemDC); m_hDispMemDC = NULL;
			DeleteObject(m_hDispMemBM); m_hDispMemBM = NULL;
		};

	while (!m_bExitThread)
	{
		if (m_arrFrames[m_nCurrFrame].m_pPicture)
		{
		///////////////////////////////////////////////////////
		// Before rendering a frame we should take care of what's 
		// behind that frame. TFrame::m_nDisposal will be our guide:
		//   0 - no disposal specified (do nothing)
		//   1 - do not dispose (again, do nothing)
		//   2 - restore to background color (m_clrBackground)
		//   3 - restore to previous

			//////// disposal method #3
			if (m_arrFrames[m_nCurrFrame].m_nDisposal == 3)
			{
				// prepare a memory DC and store the background in it
				m_hDispMemDC = CreateCompatibleDC(m_hMemDC);
				m_hDispMemBM = CreateCompatibleBitmap(m_hMemDC,
							m_arrFrames[m_nCurrFrame].m_frameSize.cx,
							m_arrFrames[m_nCurrFrame].m_frameSize.cy);
				
				if (m_hDispMemDC && m_hDispMemBM)
				{
					m_hDispOldBM = reinterpret_cast<HBITMAP> (SelectObject(m_hDispMemDC,m_hDispMemBM));
					BitBlt(m_hDispMemDC,0,0,
						m_arrFrames[m_nCurrFrame].m_frameSize.cx,
						m_arrFrames[m_nCurrFrame].m_frameSize.cy,
						m_hMemDC,
						m_arrFrames[m_nCurrFrame].m_frameOffset.cx,
						m_arrFrames[m_nCurrFrame].m_frameOffset.cy,
						SRCCOPY);