Win32 fake fullscreen and task bar visibility

To address the issue of the taskbar becoming visible when manipulating window size in a fake fullscreen mode, you may consider expanding the window size beyond the screen dimensions without removing the WS_OVERLAPPEDWINDOW style. This can be achieved by modifying the SetWindowPos function parameters to position the window off-screen without triggering the taskbar visibility.

Here is an adjusted version of the code snippet provided:

WINDOWPLACEMENT g_wpPrev = { sizeof(g_wpPrev) };
DWORD dwStyle = GetWindowLong(hWnd, GWL_STYLE);
MONITORINFO mi = { sizeof(mi) };
if (GetWindowPlacement(hWnd, &g_wpPrev) &&
    GetMonitorInfo(MonitorFromWindow(hWnd,
        MONITOR_DEFAULTTOPRIMARY), &mi)) {
    SetWindowLong(hWnd, GWL_STYLE,
        dwStyle & ~WS_OVERLAPPEDWINDOW);
    BOOL res = SetWindowPos(hWnd, HWND_TOP,
        mi.rcMonitor.left - 10, mi.rcMonitor.top - 10 - MENU_HEIGHT,   // Adjust position to be slightly off-screen
        mi.rcMonitor.right - mi.rcMonitor.left + 20, mi.rcMonitor.bottom - mi.rcMonitor.top + MENU_HEIGHT + 20,   // Adjust size to be larger than the screen dimensions
        SWP_NOOWNERZORDER | SWP_FRAMECHANGED | SWP_SHOWWINDOW);
}

By offsetting the window position by a small amount and expanding the window size slightly larger than the screen dimensions, you may be able to simulate a fake fullscreen mode for Reaper while preventing the taskbar from becoming visible.