bmphelper.cpp

visual c++ 实例编程

//
// CBMPHelper - General helper class for BMP stuff
//              Looks better than the global var/function variant of it!
//					 (No problems if we use different images on, for example, multiple views in a document) 
//
//		Also added the possible use of transparent images (normally only under Win98/Win2000 only)
//		You can copy MSIMG32.DLL also onto your WinNT4 system32 dir. Works fine..
//		Dunno for Win95..
//
//		This code runs only in transparent if the MSIMG32.DLL is found...
//		Otherwise the Non-transparent code is used to display the image
//
// Albert 'The Mad Butcher!' van Peppen, 17 Dec, 1999
//


#include "stdafx.h"
#include "BMPHelper.h"
#include "memdc.h"
#include <math.h>

CBMPHelper::CBMPHelper()
{
	m_oldRect.SetRect(0,0,0,0);
}

CRect &CBMPHelper::GetOldRect()
{
	return m_oldRect;
}

void CBMPHelper::DrawTheBackground(CWnd *view,CDC *pDC,CPalette *mp_palette,CBitmap *mp_bitmap,BOOL middle, BOOL bFitToClient, BOOL bUseTransparent)
{
	if (pDC->IsPrinting()) {
		return;
	}
	CRect rect;
	CPalette *old_palette=NULL;
	// Select and realize the palette
	if(pDC->GetDeviceCaps(RASTERCAPS) & RC_PALETTE && mp_palette->m_hObject != NULL) {
		old_palette=pDC->SelectPalette( mp_palette, FALSE );
		pDC->RealizePalette();
	}

	view->GetClientRect(rect);
	pDC->DPtoLP(rect);
	CMemDC DC(pDC,rect);
	CDC dcImage;
	if(!dcImage.CreateCompatibleDC(pDC)) {
		return;
	}

	BITMAP bm;
	mp_bitmap->GetBitmap(&bm);
	// Paint the image.
	CBitmap* pOldBitmap = dcImage.SelectObject(mp_bitmap);

	if (bUseTransparent) {
		HMODULE msimg32 = ::LoadLibrary("msimg32.dll");
		if (!msimg32) {
			TRACE("Library 'Msimg32.dll' was not loaded\n");
			goto JustNormal;			// If transparent not possible, then non-transparent...
		}
		void (WINAPI *transparentblt)(HDC,int,int,int,int,HDC,int,int,int,int,UINT);
		(FARPROC &)transparentblt = GetProcAddress(msimg32, "TransparentBlt");

		CBrush NewBrush(GetSysColor(COLOR_APPWORKSPACE));
		CBrush* pOldBrush = (CBrush*)DC->SelectObject(&NewBrush);
		CRect crect;
		m_oldRect = CRect((rect.Width()-bm.bmWidth)/2,(rect.Height()-bm.bmHeight)/2,(rect.Width()-bm.bmWidth)/2+ bm.bmWidth,(rect.Height()-bm.bmHeight)/2+ bm.bmHeight);
		pDC->GetClipBox(&crect);
		DC->PatBlt( crect.left, crect.top, crect.Width(), crect.Height(), PATCOPY);
		DC->SelectObject(pOldBrush);
		NewBrush.DeleteObject();

		if (middle || bFitToClient) {
			if (middle) {	// Just in the middle
				transparentblt(DC->m_hDC,
									m_oldRect.left, m_oldRect.top, bm.bmWidth, bm.bmHeight,
									dcImage.m_hDC,
									0, 0, bm.bmWidth, bm.bmHeight,
									GetSysColor(COLOR_WINDOW));
			}
			else {	// So, bFitToClient is TRUE ;)
				transparentblt(DC->m_hDC,
									rect.left, rect.top, rect.Width(), rect.Height(),
									dcImage.m_hDC,
									0, 0, bm.bmWidth, bm.bmHeight,
									GetSysColor(COLOR_WINDOW));
			}
		}
		else {
			int i;
			int j;
			for (i = ((int)floor((double)rect.left/bm.bmWidth)) * bm.bmWidth; i <= rect.right/*rect.Width()*/; i += bm.bmWidth) {
				for (j = ((int)floor((double)rect.top/bm.bmHeight)) * bm.bmHeight; j <= rect.bottom/*rect.Height()*/;j += bm.bmHeight) {
					transparentblt(DC->m_hDC, i, j, bm.bmWidth, bm.bmHeight, dcImage.m_hDC, 0, 0, bm.bmWidth, bm.bmHeight,GetSysColor(COLOR_WINDOW));
				}
			}
		}
		dcImage.SelectObject(pOldBitmap);
		pDC->SelectPalette(old_palette,FALSE);
		pDC->RealizePalette();

		FreeLibrary (msimg32);
	}
	else {
JustNormal:			// If no transparent possible, the jump in here
		if (middle || bFitToClient) {
			CBrush* pOldBrush = (CBrush*)DC->SelectStockObject(GRAY_BRUSH);
			CRect crect;
			m_oldRect = CRect((rect.Width()-bm.bmWidth)/2,
									(rect.Height()-bm.bmHeight)/2,
									(rect.Width()-bm.bmWidth)/2+ bm.bmWidth,
									(rect.Height()-bm.bmHeight)/2+ bm.bmHeight);
			pDC->GetClipBox(&crect);
			DC->PatBlt(crect.left, crect.top, crect.Width(), crect.Height(), PATCOPY);
			DC->SelectObject(pOldBrush);
			if (middle) {	// Just in the middle
				DC->BitBlt(m_oldRect.left, m_oldRect.top, bm.bmWidth, bm.bmHeight, &dcImage, 0, 0, SRCCOPY);
			}
			else {	// So, bFitToClient is TRUE ;)
				DC->StretchBlt(rect.left, rect.top, rect.Width(), rect.Height(), &dcImage, 0, 0, bm.bmWidth, bm.bmHeight, SRCCOPY);
			}
		}
		else {
			int i;
			int j;
			for (i = ((int)floor((double)rect.left/bm.bmWidth)) * bm.bmWidth; i <= rect.right/*rect.Width()*/; i += bm.bmWidth) {
				for (j = ((int)floor((double)rect.top/bm.bmHeight))*bm.bmHeight; j <= rect.bottom/*rect.Height()*/;j += bm.bmHeight) {
					DC->BitBlt(i, j, bm.bmWidth, bm.bmHeight, &dcImage, 0, 0, SRCCOPY);
				}
			}
		}
		dcImage.SelectObject(pOldBitmap);
		pDC->SelectPalette(old_palette,FALSE);
		pDC->RealizePalette();
	}
}

BOOL CBMPHelper::GetBitmapAndPalette(UINT nIDResource, CBitmap &bitmap, CPalette &pal)
{
	LPCTSTR lpszResourceName = (LPCTSTR)nIDResource;
	HBITMAP hBmp = (HBITMAP)::LoadImage( AfxGetInstanceHandle(),
													 lpszResourceName, IMAGE_BITMAP, 0,0, LR_CREATEDIBSECTION );
	if (hBmp == NULL) {
		return FALSE;
	}
	bitmap.Attach( hBmp );

	// Create a logical palette for the bitmap
	DIBSECTION ds;
	BITMAPINFOHEADER &bmInfo = ds.dsBmih;
	bitmap.GetObject( sizeof(ds), &ds );

	int nColors = bmInfo.biClrUsed ? bmInfo.biClrUsed : 1 << bmInfo.biBitCount;

	// Create a halftone palette if colors > 256. 
	CClientDC dc(NULL); // Desktop DC
	if (nColors > 256) {
		pal.CreateHalftonePalette( &dc );
	}
	else {
		// Create the palette
		RGBQUAD *pRGB = new RGBQUAD[nColors];
		CDC memDC;
		memDC.CreateCompatibleDC(&dc);
		memDC.SelectObject( &bitmap );
		::GetDIBColorTable( memDC, 0, nColors, pRGB );
		UINT nSize = sizeof(LOGPALETTE) + (sizeof(PALETTEENTRY) * nColors);
		LOGPALETTE *pLP = (LOGPALETTE *) new BYTE[nSize];
		pLP->palVersion = 0x300;
		pLP->palNumEntries = nColors;
		for( int i=0; i < nColors; i++) {
			pLP->palPalEntry[i].peRed = pRGB[i].rgbRed;
			pLP->palPalEntry[i].peGreen = pRGB[i].rgbGreen;
			pLP->palPalEntry[i].peBlue = pRGB[i].rgbBlue;
			pLP->palPalEntry[i].peFlags = 0;
		}
		pal.CreatePalette( pLP );
		delete[] pLP;
		delete[] pRGB;
	}
	return TRUE;
}