//////////////////////////////////////////////////////////////////////
// PictureEx.cpp: implementation of the CPictureEx class.
//
// Picture displaying control with support for the following formats:
// GIF (including animated GIF87a and GIF89a), JPEG, BMP, WMF, ICO, CUR
// 
// Written by Oleg Bykov (oleg_bykoff@rsdn.ru)
// Copyright (c) 2001
//
// To use CPictureEx, follow these steps:
//   - place a static control on your dialog (either a text or a bitmap)
//   - change its identifier to something else (e.g. IDC_MYPIC)
//   - associate a CStatic with it using ClassWizard
//   - in your dialog's header file replace CStatic with CPictureEx
//     (don't forget to #include "PictureEx.h" and add 
//     PictureEx.h and PictureEx.cpp to your project)
//   - call one of the overloaded CPictureEx::Load() functions somewhere
//     (OnInitDialog is a good place to start)
//   - if the preceding Load() succeeded call Draw()
//  
// You can also add the control by defining a member variable of type 
// CPictureEx, calling CPictureEx::Create (derived from CStatic), then 
// CPictureEx::Load and CPictureEx::Draw.
//
// By default, the control initializes its background to COLOR_3DFACE
// (see CPictureEx::PrepareDC()). You can change the background by
// calling CPictureEx::SetBkColor(COLORREF) after CPictureEx::Load().
//
// I decided to leave in the class the functions to write separate frames from 
// animated GIF to disk. If you want to use them, uncomment #define GIF_TRACING 
// and an appropriate section in CPictureEx::Load(HGLOBAL, DWORD). These functions 
// won't be compiled and linked to your project unless you uncomment #define GIF_TRACING,
// so you don't have to worry.
// 
// Warning: this code hasn't been subject to a heavy testing, so
// use it on your own risk. The author accepts no liability for the 
// possible damage caused by this code.
//
// Version 1.0  7 Aug 2001
//              Initial release
//
// Version 1.1  6 Sept 2001
//              ATL version of the class
//
// Version 1.2  14 Oct 2001
//              - Fixed a problem with loading GIFs from resources
//                in MFC-version of the class for multi-modules apps.
//                Thanks to Ruben Avila-Carretero for finding this out.
//
//              - Got rid of waitable timer in ThreadAnimation()
//                Now CPictureEx[Wnd] works in Win95 too.
//                Thanks to Alex Egiazarov and Wayne King for the idea.
//
//              - Fixed a visual glitch of using SetBkColor.
//                Thanks to Kwangjin Lee for finding this out.
//
// Version 1.3  10 Nov 2001
//              - Fixed a DC leak. One DC leaked per each UnLoad()
//                (forgot to put a ReleaseDC() in the end of 
//                CPictureExWnd::PrepareDC() function).
//
//              - Now it is possible to set a clipping rectangle using
//                CPictureEx[Wnd]::SetPaintRect(const LPRECT) function.
//                The LPRECT parameter tells the class what portion of
//                a picture should it display. If the clipping rect is 
//                not set, the whole picture is shown.
//                Thanks to Fabrice Rodriguez for the idea.
//
//              - Added support for Stop/Draw. Now you can Stop() an
//                animated GIF, then Draw() it again, it will continue
//                animation from the frame it was stopped on. You can 
//                also know if a GIF is currently playing with the 
//                IsPlaying() function.
//             
//              - Got rid of math.h and made m_bExitThread volatile. 
//                Thanks to Piotr Sawicki for the suggestion.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "PictureEx.h"
#include <process.h>

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

//////////////////////////////////////////////////////////////////////
// Nested structures member functions
//////////////////////////////////////////////////////////////////////

inline int CPictureEx::TGIFControlExt::GetPackedValue(enum ControlExtValues Value)
{
	int nRet = (int)m_cPacked;
	switch (Value)
	{
	case GCX_PACKED_DISPOSAL:
		nRet = (nRet & 28) >> 2;
		break;

	case GCX_PACKED_USERINPUT:
		nRet = (nRet & 2) >> 1;
		break;

	case GCX_PACKED_TRANSPCOLOR:
		nRet &= 1;
		break;
	};

	return nRet;
}

inline int CPictureEx::TGIFLSDescriptor::GetPackedValue(enum LSDPackedValues Value)
{
	int nRet = (int)m_cPacked;

	switch (Value)
	{
	case LSD_PACKED_GLOBALCT:
		nRet = nRet >> 7;
		break;

	case LSD_PACKED_CRESOLUTION:
		nRet = ((nRet & 0x70) >> 4) + 1;
		break;

	case LSD_PACKED_SORT:
		nRet = (nRet & 8) >> 3;
		break;

	case LSD_PACKED_GLOBALCTSIZE:
		nRet &= 7;
		break;
	};

	return nRet;
}

inline int CPictureEx::TGIFImageDescriptor::GetPackedValue(enum IDPackedValues Value)
{
	int nRet = (int)m_cPacked;

	switch (Value)
	{
	case ID_PACKED_LOCALCT:
		nRet >>= 7;
		break;

	case ID_PACKED_INTERLACE:
		nRet = ((nRet & 0x40) >> 6);
		break;

	case ID_PACKED_SORT:
		nRet = (nRet & 0x20) >> 5;
		break;

	case ID_PACKED_LOCALCTSIZE:
		nRet &= 7;
		break;
	};

	return nRet;
}


//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CPictureEx::CPictureEx()
{
	// check structures size
	ASSERT(sizeof(TGIFImageDescriptor) == 10);
	ASSERT(sizeof(TGIFAppExtension)    == 14);
	ASSERT(sizeof(TGIFPlainTextExt)    == 15);
	ASSERT(sizeof(TGIFLSDescriptor)    ==  7);
	ASSERT(sizeof(TGIFControlExt)	   ==  8);
	ASSERT(sizeof(TGIFCommentExt)	   ==  2);
	ASSERT(sizeof(TGIFHeader)		   ==  6);

	m_pGIFLSDescriptor = NULL;
	m_pGIFHeader	   = NULL;
	m_pPicture		   = NULL;
	m_pRawData		   = NULL;
	m_hThread		   = NULL;
	m_hBitmap          = NULL;
	m_hMemDC		   = NULL;

	m_hDispMemDC       = NULL;
	m_hDispMemBM       = NULL;
	m_hDispOldBM       = NULL;

	m_bIsInitialized   = FALSE;
	m_bExitThread	   = FALSE;
	m_bIsPlaying       = 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;
	m_PictureSize.cx = m_PictureSize.cy = 0;
	SetRect(&m_PaintRect,0,0,0,0);

	m_hExitEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
}

CPictureEx::~CPictureEx()
{
	UnLoad();
	CloseHandle(m_hExitEvent);
}

BEGIN_MESSAGE_MAP(CPictureEx, CStatic)
	//{{AFX_MSG_MAP(CPictureEx)
	ON_WM_DESTROY()
	ON_WM_PAINT()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

BOOL CPictureEx::Load(HGLOBAL hGlobal, DWORD dwSize)
{
	IStream *pStream = NULL;
	UnLoad();

	if (!(m_pRawData = reinterpret_cast<unsigned char*> (GlobalLock(hGlobal))) )
	{
		TRACE(_T("Load: Error locking memory\n"));
		return FALSE;
	};

	m_nDataSize = dwSize;
	m_pGIFHeader = reinterpret_cast<TGIFHeader *> (m_pRawData);

	if ((memcmp(&m_pGIFHeader->m_cSignature,"GIF",3) != 0) &&
		((memcmp(&m_pGIFHeader->m_cVersion,"87a",3) != 0) ||
		 (memcmp(&m_pGIFHeader->m_cVersion,"89a",3) != 0)) )
	{
	// it's neither GIF87a nor GIF89a
	// do the default processing

		// clear GIF variables
		m_pRawData = NULL;
		GlobalUnlock(hGlobal);

		// don't delete memory on object's release
		if (CreateStreamOnHGlobal(hGlobal,FALSE,&pStream) != S_OK)
			return FALSE;

		if (OleLoadPicture(pStream,dwSize,FALSE,IID_IPicture,
			reinterpret_cast<LPVOID *>(&m_pPicture)) != S_OK)
		{
			pStream->Release();
			return FALSE;
		};
		pStream->Release();

		// store picture's size

		long hmWidth;
		long hmHeight;
		m_pPicture->get_Width(&hmWidth);
		m_pPicture->get_Height(&hmHeight);

		HDC hDC = ::GetDC(m_hWnd);
		m_PictureSize.cx = MulDiv(hmWidth, GetDeviceCaps(hDC,LOGPIXELSX), 2540);
		m_PictureSize.cy = MulDiv(hmHeight, GetDeviceCaps(hDC,LOGPIXELSY), 2540);
		::ReleaseDC(m_hWnd,hDC);
	}
	else
	{
		// it's a GIF
		m_bIsGIF = TRUE;
		m_pGIFLSDescriptor = reinterpret_cast<TGIFLSDescriptor *>
			(m_pRawData + sizeof(TGIFHeader));
		if (m_pGIFLSDescriptor->GetPackedValue(LSD_PACKED_GLOBALCT) == 1)
		{
			// calculate the globat color table size
			m_nGlobalCTSize = static_cast<int>
				(3* (1 << (m_pGIFLSDescriptor->GetPackedValue(LSD_PACKED_GLOBALCTSIZE)+1)));
			// get the background color if GCT is present
			unsigned char *pBkClr = m_pRawData + sizeof(TGIFHeader) + 
				sizeof(TGIFLSDescriptor) + 3*m_pGIFLSDescriptor->m_cBkIndex;
			m_clrBackground = RGB(pBkClr[0],pBkClr[1],pBkClr[2]);
		};

		// store the picture's size
		m_PictureSize.cx = m_pGIFLSDescriptor->m_wWidth;
		m_PictureSize.cy = m_pGIFLSDescriptor->m_wHeight;

		// determine frame count for this picture
		UINT nFrameCount=0;
		ResetDataPointer();
		while (SkipNextGraphicBlock())
			nFrameCount++;

#ifdef GIF_TRACING
		TRACE(
			_T(" -= GIF encountered\n"
			   "Logical Screen dimensions = %dx%d\n"
			   "Global color table = %d\n"
			   "Color depth = %d\n"
			   "Sort flag = %d\n"
			   "Size of Global Color Table = %d\n"
			   "Background color index = %d\n"
			   "Pixel aspect ratio = %d\n"
			   "Frame count = %d\n"
			   "Background color = %06Xh\n\n"
			  ),
			m_pGIFLSDescriptor->m_wWidth,
			m_pGIFLSDescriptor->m_wHeight,
			m_pGIFLSDescriptor->GetPackedValue(LSD_PACKED_GLOBALCT),
			m_pGIFLSDescriptor->GetPackedValue(LSD_PACKED_CRESOLUTION),
			m_pGIFLSDescriptor->GetPackedValue(LSD_PACKED_SORT),
			m_pGIFLSDescriptor->GetPackedValue(LSD_PACKED_GLOBALCTSIZE),
			m_pGIFLSDescriptor->m_cBkIndex,
			m_pGIFLSDescriptor->m_cPixelAspect,
			nFrameCount,
			m_clrBackground
			);
		EnumGIFBlocks();
#endif

		if (nFrameCount == 0) // it's an empty GIF!
		{
			m_pRawData = NULL;
			GlobalUnlock(hGlobal);
			return FALSE;
		};

		// now check the frame count
		// if there's only one frame, no need to animate this GIF
		// therefore, treat it like any other pic

		if (nFrameCount == 1)
		{
			// clear GIF variables
			m_pRawData = NULL;
			GlobalUnlock(hGlobal);

			// don't delete memory on object's release
			if (CreateStreamOnHGlobal(hGlobal,FALSE,&pStream) != S_OK)
				return FALSE;

			if (OleLoadPicture(pStream,dwSize,FALSE,IID_IPicture,
				(LPVOID *)&m_pPicture) != S_OK)
			{
				pStream->Release();
				return FALSE;
			};

			pStream->Release();
		}
		else
		{
		// if, on the contrary, there are several frames
		// then store separate frames in an array

			TFrame frame;
			UINT nBlockLen;
			HGLOBAL hFrameData;
			UINT nCurFrame = 0;

			ResetDataPointer();
			while (hFrameData = GetNextGraphicBlock(&nBlockLen,
				&frame.m_nDelay, &frame.m_frameSize,
				&frame.m_frameOffset, &frame.m_nDisposal) )
			{
				#ifdef GIF_TRACING
				//////////////////////////////////////////////
				// uncomment the following strings if you want 
				// to write separate frames on disk
				//
				//	CString szName;
				//	szName.Format(_T("%.4d.gif"),nCurFrame);
				//	WriteDataOnDisk(szName,hFrameData,nBlockLen);
				//	nCurFrame++;
				#endif // GIF_TRACING

				IStream *pStream = NULL;

				// delete memory on object's release
				if (CreateStreamOnHGlobal(hFrameData,TRUE,&pStream) != S_OK)
				{
					GlobalFree(hFrameData);
					continue;
				};

				if (OleLoadPicture(pStream,nBlockLen,FALSE,
					IID_IPicture,
					reinterpret_cast<LPVOID *>(&frame.m_pPicture)) != S_OK)
				{
					pStream->Release();
					continue;
				};
				pStream->Release();
			
				// everything went well, add this frame
				m_arrFrames.push_back(frame);
			};

			// clean after ourselves
			m_pRawData = NULL;
			GlobalUnlock(hGlobal);

			if (m_arrFrames.empty()) // couldn't load any frames
				return FALSE;
		};
	}; // if (!IsGIF...

	return PrepareDC(m_PictureSize.cx,m_PictureSize.cy);
}

void CPictureEx::UnLoad()
{
	Stop();
	if (m_pPicture)
	{
		m_pPicture->Release();
		m_pPicture = NULL;
	};
	
	std::vector<TFrame>::iterator it;
	for (it=m_arrFrames.begin();it<m_arrFrames.end();it++)
		(*it).m_pPicture->Release();
	m_arrFrames.clear();

	if (m_hMemDC)
	{
		SelectObject(m_hMemDC,m_hOldBitmap);
		::DeleteDC(m_hMemDC);
		::DeleteObject(m_hBitmap);
		m_hMemDC  = NULL;
		m_hBitmap = NULL;
	};