enbitmap.cpp

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// EnBitmap.cpp: implementation of the CEnBitmap class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "EnBitmap.h"
#include <AFXPRIV.H>

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

const int HIMETRIC_INCH	= 2540;

enum 
{
	FT_BMP,
	FT_ICO,
	FT_JPG,
	FT_GIF,

	FT_UNKNOWN
};

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

CEnBitmap::CEnBitmap()
{

}

CEnBitmap::~CEnBitmap()
{

}

BOOL CEnBitmap::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;

	return Attach(LoadImageResource(uIDRes, szResourceType, hInst, crBack));
}

BOOL CEnBitmap::LoadImage(LPCTSTR szImagePath, COLORREF crBack)
{
	//如果原先存在就去除
	if (m_hObject != NULL)
	{
		DeleteObject();
		Detach();
	}

	return Attach(LoadImageFile(szImagePath, crBack));
}

HBITMAP CEnBitmap::LoadImageFile(LPCTSTR szImagePath, COLORREF crBack)
{
	int nType = GetFileType(szImagePath);

	switch (nType)
	{
		// the reason for this is that i suspect it is more efficient to load
		// bmps this way since it avoids creating device contexts etc that the 
		// IPicture methods requires. that method however is still valuable
		// since it handles other image types and transparency
		case FT_BMP:
			return (HBITMAP)::LoadImage(NULL, szImagePath, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);

		case FT_UNKNOWN:
			return NULL;

		default: // all the rest
		{
			USES_CONVERSION;
			IPicture* pPicture = NULL;
			
			HBITMAP hbm = NULL;
			HRESULT hr = OleLoadPicturePath(T2OLE(szImagePath), NULL, 0, crBack, IID_IPicture, (LPVOID *)&pPicture);
					
			if (pPicture)
			{
				hbm = ExtractBitmap(pPicture, crBack);
				pPicture->Release();
			}

			return hbm;
		}
	}

	return NULL; // can't get here
}

HBITMAP CEnBitmap::LoadImageResource(UINT uIDRes, LPCTSTR szResourceType, HMODULE hInst, COLORREF crBack)
{
	BYTE* pBuff = NULL;
	int nSize = 0;
	HBITMAP hbm = NULL;

	// 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)
				{
					hbm = ExtractBitmap(pPicture, crBack);
					pPicture->Release();
				}
			}
			
			delete [] pBuff;
		}
	}

	return hbm;
}

IPicture* CEnBitmap::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 CEnBitmap::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;
}

HBITMAP CEnBitmap::ExtractBitmap(IPicture* pPicture, COLORREF crBack)
{
	ASSERT(pPicture);

	if (!pPicture)
		return NULL;

	CBitmap bmMem;
	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);

		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);
		}
	}

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

	return (HBITMAP)bmMem.Detach();
}

int CEnBitmap::GetFileType(LPCTSTR szImagePath)
{
	CString sPath(szImagePath);
	sPath.MakeUpper();

	if (sPath.Find(".BMP") > 0)
		return FT_BMP;

	else if (sPath.Find(".ICO") > 0)
		return FT_ICO;

	else if (sPath.Find(".JPG") > 0 || sPath.Find(".JPEG") > 0)
		return FT_JPG;

	else if (sPath.Find(".GIF") > 0)
		return FT_GIF;

	// else
	return FT_UNKNOWN;
}

/////////////////////////////////////////////////////////////////////
// Converts a bitmap to a region
//
//	BitmapToRegion :	Create a region from the "non-transparent" pixels of a bitmap
//	Author :			Jean-Edouard Lachand-Robert (http://www.geocities.com/Paris/LeftBank/1160/resume.htm), June 1998.
//
//	hBmp :				Source bitmap
//	cTransparentColor :	Color base for the "transparent" pixels (default is black)
//	cTolerance :		Color tolerance for the "transparent" pixels.
//
//	A pixel is assumed to be transparent if the value of each of its 3 components (blue, green and red) is 
//	greater or equal to the corresponding value in cTransparentColor and is lower or equal to the 
//	corresponding value in cTransparentColor + cTolerance.
//
HRGN CEnBitmap::BitmapToRegion( COLORREF cTransparentColor ,COLORREF cTolerance)
{
	HBITMAP hBmp = (HBITMAP)GetSafeHandle();
	HRGN hRgn = NULL;

	if(hBmp)
	{
		// Create a memory DC inside which we will scan the bitmap content
		HDC hMemDC = CreateCompatibleDC(NULL);
		if(hMemDC)
		{
			// Get bitmap size
			BITMAP bm;
			::GetObject(hBmp, sizeof(bm), &bm);

			// Create a 32 bits depth bitmap and select it into the memory DC 
			BITMAPINFOHEADER RGB32BITSBITMAPINFO = {	
					sizeof(BITMAPINFOHEADER),	// biSize 
					bm.bmWidth,					// biWidth; 
					bm.bmHeight,				// biHeight; 
					1,							// biPlanes; 
					32,							// biBitCount 
					BI_RGB,						// biCompression; 
					0,							// biSizeImage; 
					0,							// biXPelsPerMeter; 
					0,							// biYPelsPerMeter; 
					0,							// biClrUsed; 
					0							// biClrImportant; 
			};
			VOID * pbits32; 
			HBITMAP hbm32 = CreateDIBSection(hMemDC, (BITMAPINFO *)&RGB32BITSBITMAPINFO, DIB_RGB_COLORS, &pbits32, NULL, 0);
			if(hbm32)
			{
				HBITMAP holdBmp = (HBITMAP)SelectObject(hMemDC, hbm32);

				// Create a DC just to copy the bitmap into the memory DC
				HDC hDC = CreateCompatibleDC(hMemDC);
				if(hDC)
				{
					// Get how many bytes per row we have for the bitmap bits (rounded up to 32 bits)
					BITMAP bm32;
					::GetObject(hbm32, sizeof(bm32), &bm32);
					while(bm32.bmWidthBytes % 4)
						bm32.bmWidthBytes++;

					// Copy the bitmap into the memory DC
					HBITMAP holdBmp = (HBITMAP)SelectObject(hDC, hBmp);
					BitBlt(hMemDC, 0, 0, bm.bmWidth, bm.bmHeight, hDC, 0, 0, SRCCOPY);

					// For better performances, we will use the ExtCreateRegion() function to create the
					// region. This function take a RGNDATA structure on entry. We will add rectangles by
					// amount of ALLOC_UNIT number in this structure.
					#define ALLOC_UNIT	100
					DWORD maxRects = ALLOC_UNIT;
					HANDLE hData = GlobalAlloc(GMEM_MOVEABLE, sizeof(RGNDATAHEADER) + (sizeof(RECT) * maxRects));
					RGNDATA *pData = (RGNDATA *)GlobalLock(hData);
					pData->rdh.dwSize = sizeof(RGNDATAHEADER);
					pData->rdh.iType = RDH_RECTANGLES;
					pData->rdh.nCount = pData->rdh.nRgnSize = 0;
					SetRect(&pData->rdh.rcBound, MAXLONG, MAXLONG, 0, 0);

					// Keep on hand highest and lowest values for the "transparent" pixels
					BYTE lr = GetRValue(cTransparentColor);
					BYTE lg = GetGValue(cTransparentColor);
					BYTE lb = GetBValue(cTransparentColor);
					BYTE hr = min(0xff, lr + GetRValue(cTolerance));
					BYTE hg = min(0xff, lg + GetGValue(cTolerance));
					BYTE hb = min(0xff, lb + GetBValue(cTolerance));

					// Scan each bitmap row from bottom to top (the bitmap is inverted vertically)
					BYTE *p32 = (BYTE *)bm32.bmBits + (bm32.bmHeight - 1) * bm32.bmWidthBytes;
					for(int y = 0; y < bm.bmHeight; y++)
					{
						// Scan each bitmap pixel from left to right
						for(int x = 0; x < bm.bmWidth; x++)
						{
							// Search for a continuous range of "non transparent pixels"
							int x0 = x;
							LONG *p = (LONG *)p32 + x;
							while(x < bm.bmWidth)
							{
								BYTE b = GetRValue(*p);
								if(b >= lr && b <= hr)
								{
									b = GetGValue(*p);
									if(b >= lg && b <= hg)
									{
										b = GetBValue(*p);
										if(b >= lb && b <= hb)
											// This pixel is "transparent"
											break;
									}
								}
								p++;
								x++;
							}

							if(x > x0)
							{
								// Add the pixels (x0, y) to (x, y+1) as a new rectangle in the region
								if(pData->rdh.nCount >= maxRects)
								{
									GlobalUnlock(hData);
									maxRects += ALLOC_UNIT;
									hData = GlobalReAlloc(hData, sizeof(RGNDATAHEADER) + (sizeof(RECT) * maxRects), GMEM_MOVEABLE);
									pData = (RGNDATA *)GlobalLock(hData);
								}
								RECT *pr = (RECT *)&pData->Buffer;
								SetRect(&pr[pData->rdh.nCount], x0, y, x, y+1);
								if(x0 < pData->rdh.rcBound.left)
									pData->rdh.rcBound.left = x0;
								if(y < pData->rdh.rcBound.top)
									pData->rdh.rcBound.top = y;
								if(x > pData->rdh.rcBound.right)
									pData->rdh.rcBound.right = x;
								if(y+1 > pData->rdh.rcBound.bottom)
									pData->rdh.rcBound.bottom = y+1;
								pData->rdh.nCount++;

								// On Windows98, ExtCreateRegion() may fail if the number of rectangles is too
								// large (ie: > 4000). Therefore, we have to create the region by multiple steps.
								if(pData->rdh.nCount == 2000)
								{
									HRGN h = ExtCreateRegion(NULL, sizeof(RGNDATAHEADER) + (sizeof(RECT) * maxRects), pData);
									if(hRgn)
									{
										CombineRgn(hRgn, hRgn, h, RGN_OR);
										::DeleteObject(h);
									}