Win32 Double Buffering

// settingsconst int width = 400;const int height = 300;// varsHDC bufDC;HBITMAP bufBMP;// set upbufDC = CreateCompatibleDC(hDC);bufBMP = CreateCompatibleBitmap(hDC, width, height);SelectObject(bufDC, bufBMP);// draw to the bufferMoveToEx(bufDC, 100, 100, NULL);LineTo(bufDC, 200, 200);// present the bufferBitBlt(hDC, 0, 0, width, height, bufDC, 0, 0, SRCCOPY);

    const int height = 471;    const int width = 648;        HBRUSH Brush;    HBITMAP hbmOld;    HBITMAP Bitmap;    HBITMAP BufferBitmap;                 hdc = BeginPaint(hwnd, &ps);        HDC bufferDC = CreateCompatibleDC(hdc);    BufferBitmap = CreateCompatibleBitmap(hdc, width, height);    SelectObject(bufferDC, BufferBitmap);        Bitmap = GetTile();    hbmOld = (HBITMAP)SelectObject(BufferBitmap, Bitmap);    BitBlt(bufferDC, X, Y, 32, 32, (HDC)BufferBitmap, 0, 0, SRCCOPY);        BitBlt(hdc, 0, 0, width, height, bufferDC, 0, 0, SRCCOPY);        SelectObject(bufferDC, hbmOld);    DeleteDC(bufferDC);    DeleteObject(BufferBitmap);         DeleteObject(Brush);    EndPaint(hwnd, &ps);

void PaintScreen(){    if(MapX < 0){MapX = 0;}    if(MapX > 85){MapX = 85;}    if(MapY < 0){MapY = 0;}    if(MapY > 88){MapY = 88;}    GetScreen(MapX,MapY);        const int height = 471;    const int width = 648;        HBRUSH Brush;    HBITMAP hbmOld;    HBITMAP Bitmap;    HBITMAP BufferBitmap;                 hdc = BeginPaint(hwnd, &ps);        HDC bufferDC = CreateCompatibleDC(hdc);    BufferBitmap = CreateCompatibleBitmap(hdc, width, height);    SelectObject(bufferDC, BufferBitmap);                 //Fill background    Brush = CreateSolidBrush(RGB(0, 105, 130));    SelectObject(bufferDC, Brush);    Rectangle(bufferDC, 126, 0, 624, 400);    current = 0; //Current tile being drawn to screen    int X = 128;    int Y = 2;    int ColCount = 0;    for(int i = 0; i < 180; i++)    {        Bitmap = GetTile();        hbmOld = (HBITMAP)SelectObject(BufferBitmap, Bitmap);        BitBlt(bufferDC, X, Y, 32, 32, (HDC)BufferBitmap, 0, 0, SRCCOPY);        ColCount++;        current++;        X += 33;        if(ColCount >= 15)        {            ColCount = 0;            X = 128;            Y += 33;        }    }            BitBlt(hdc, 0, 0, width, height, bufferDC, 0, 0, SRCCOPY);        SelectObject(bufferDC, hbmOld);    DeleteDC(bufferDC);    DeleteObject(BufferBitmap);         DeleteObject(Brush);    EndPaint(hwnd, &ps);}

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/* Windows 2000 Graphics API Black Book Double-Buffer Multiple or Expensive Rendering Operations To implement a double-buffered solution, you perform the following steps: 1. Use the CreateCompatibleDC function to create a memory device context that is compatible with the target display device. 2. Create an appropriately sized device-dependent bitmap or DIB section bitmap that will serve as the "memory" of the memory device context. You can use the CreateCompatibleBitmap function to create a device-dependent bitmap or the CreateDIBSection function to create a DIB section bitmap. 3. Use the SelectObject function to select the bitmap into the memory device context. 4. Direct any rendering to the memory device context. You can simply modify your existing code by replacing all references to the original target device context with references to the memory device context. 5. When the rendering is complete, use the BitBlt function to transfer the bits of the bitmap to the original target device context. */

HDC hdc;HBITMAP Bitmap;PAINTSTRUCT ps;...HDC memHdc;HDC bufHdc;HBITMAP buffer;hdc = BeginPaint(hwnd, &ps);bufHdc = CreateCompatibleDC(hdc);hdcMem = CreateCompatibleDC(bufHdc);buffer = CreateCompatibleBitmap(hdc);//make buffer be my imagesbuffer = Bitmap;SelectObject(hdcMem, buffer);//Do my blitting to the backbufferBltBit(bufHdc, 0, 0, 32, 32, hdcMem, 0, 0, SRCCOPY);//And finally paint to the screenBltBit(hdc, 0, 0, width, hieght, bufHdc, 0, 0, SRCCOPY);/*Clean up*/

HDC hdc;HDC memHdc;HBITMAP bitmap;// instead of BeginPaint use GetDC or GetWindowDChdc = GetDC(hwnd); hdcMem = CreateCompatibleDC(hdc); // always create the bitmap for the memdc from the window dcbitmap = CreateCompatibleBitmap(hdc,width,height);SelectObject(hdcMem, bitmap);// only execute the code up to this point one time// that is, you only need to create the back buffer once// you can reuse it over and over again after that// draw on hdcMem// for example  ...Rectangle(hdcMem, 126, 0, 624, 400);// when finished drawing blit the hdcMem to the hdcBltBit(hdc, 0, 0, width, height, hdcMem, 0, 0, SRCCOPY);// note, height is not spelled i before e// Clean up - only need to do this one time as wellDeleteDC(hdcMem);DeleteObject(bitmap);ReleaseDC(hwnd, hdc);

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When the entire client area of your window is to be covered by a drawing, you should instruct the default window procedure not to fill the background with the class background-brush object. You can do this by assigning NULL (or the NULL_BRUSH stock object) to the WNDCLASS::hbrBackground data member before the window’s class is registered: An equivalent technique is to always return non-zero in response to the WM_ERASEBKGND message: