下雪 MFC/VS2008

// FlakeDlg.cpp : implementation file // #include "stdafx.h" #include "Snow.h" #include "FlakeDlg.h" #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif ///////////////////////////////////////////////////////////////////////////// // CFlakeDlg dialog CFlakeDlg::CFlakeDlg(int nTimer, int nPosX, CWnd* pParent /*=NULL*/) : CDialog(CFlakeDlg::IDD, pParent) { //{{AFX_DATA_INIT(CFlakeDlg) m_nTimer = nTimer; m_nCurrentX = nPosX; m_nCurrentY = 0; m_nCounter = 0; m_nIncrement = 1; //}}AFX_DATA_INIT } void CFlakeDlg::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); //{{AFX_DATA_MAP(CFlakeDlg) // NOTE: the ClassWizard will add DDX and DDV calls here //}}AFX_DATA_MAP } BEGIN_MESSAGE_MAP(CFlakeDlg, CDialog) //{{AFX_MSG_MAP(CFlakeDlg) ON_WM_TIMER() ON_WM_DESTROY() ON_WM_CTLCOLOR() //}}AFX_MSG_MAP END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // CFlakeDlg message handlers BOOL CFlakeDlg::OnInitDialog() { CDialog::OnInitDialog(); CRect rcWorkArea; SystemParametersInfo(SPI_GETWORKAREA,0,(LPVOID)&rcWorkArea,0); m_nScreenWidth = rcWorkArea.Width(); m_nScreenHeight = rcWorkArea.Height(); m_hFlake = LoadBitmap(AfxGetInstanceHandle(),MAKEINTRESOURCE(IDB_BITMAP_FLAKE)); HRGN hRgn = BitmapToRegion(m_hFlake,RGB(255,255,255)); SetWindowRgn(hRgn, TRUE); SetTimer(1,m_nTimer,0); return TRUE; } void CFlakeDlg::OnTimer(UINT nIDEvent) { if(nIDEvent == 1) { KillTimer(1); m_nCurrentY += 5; m_nCounter++; if(m_nCounter == 15) { if(((rand()*10/RAND_MAX)-5)>0) m_nIncrement = 1; else m_nIncrement = -1; m_nCounter = 0; } m_nCurrentX += m_nIncrement; if(m_nCurrentY>m_nScreenHeight) { m_nCurrentY = 0; m_nCurrentX = abs(rand()*m_nScreenWidth/RAND_MAX); m_nTimer = abs(rand()*50/RAND_MAX); } MoveWindow(m_nCurrentX,m_nCurrentY,17,17); SetTimer(1,m_nTimer,0); } CDialog::OnTimer(nIDEvent); } HBRUSH CFlakeDlg::OnCtlColor(CDC* pDC, CWnd* pWnd, UINT nCtlColor) { return (HBRUSH)GetStockObject(WHITE_BRUSH); } void CFlakeDlg::OnCancel() { // CDialog::OnCancel(); } void CFlakeDlg::OnOK() { // CDialog::OnOK(); } void CFlakeDlg::OnDestroy() { CDialog::OnDestroy(); if(m_hFlake) DeleteObject(m_hFlake); } HRGN CFlakeDlg::BitmapToRegion (HBITMAP hBmp, COLORREF cTransparentColor, COLORREF cTolerance) { 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); } else hRgn = h; pData->rdh.nCount = 0; SetRect(&pData->rdh.rcBound, MAXLONG, MAXLONG, 0, 0); } } } // Go to next row (remember, the bitmap is inverted vertically) p32 -= bm32.bmWidthBytes; } // Create or extend the region with the remaining rectangles HRGN h = ExtCreateRegion(NULL, sizeof(RGNDATAHEADER) + (sizeof(RECT) * maxRects), pData); if (hRgn) { CombineRgn(hRgn, hRgn, h, RGN_OR); DeleteObject(h); } else hRgn = h; // Clean up GlobalFree(hData); SelectObject(hDC, holdBmp); DeleteDC(hDC); } DeleteObject(SelectObject(hMemDC, holdBmp)); } DeleteDC(hMemDC); } } return hRg