double Microsoft.UI.Input.PointerPoint.Position should be int

[Padanian]

Describe the bug

Consider the following

` 
        Microsoft.UI.Input.PointerPoint ptrPt;
        IntPtr hWnd;
        WindowId windowId;
        AppWindow appWindow;

        private void Grid_PointerMoved(object sender, PointerRoutedEventArgs e)
        {
             hWnd = WinRT.Interop.WindowNative.GetWindowHandle(this);
             windowId = Microsoft.UI.Win32Interop.GetWindowIdFromWindow(hWnd);
             appWindow = Microsoft.UI.Windowing.AppWindow.GetFromWindowId(windowId);
             ptrPt = e.GetCurrentPoint(null);

             eDiff.X =  appWindow.Position.X + (int)ptrPt.Position.X;
             eDiff.Y =  appWindow.Position.Y + (int)ptrPt.Position.Y;

             // Set the new point
             appWindow.Move(eDiff);

        }

`

Is there any good reason why appWindow.Position.X is int while the pointer position is double?

Steps to reproduce the bug

See example above

Expected behavior

Pointer should be int.

Screenshots

No response

NuGet package version

WinUI 3 - Windows App SDK 1.1.1

Windows app type

• UWP
• Win32

Device form factor

Desktop

Windows version

Windows 11 (21H2): Build 22000

Additional context

No response

[krschau]

@jlnordin, is this something you can speak to?

[jlnordin]

There are a few reasons:

• AppWindow uses integers to better integrate with Win32 HWND concepts. A Win32 window can only be positioned on integer boundaries, so we use Ints in that API.
• Windows App SDK's PointerPoint (Microsoft.UI.Input.PointerPoint) is based on the Windows Platform SDK's PointerPoint (Windows.UI.Input.PointerPoint) and we wanted to make porting between these two easier.
• PointerPoint can also be arbitrarily modified by scales, rotations, or other transformations depending on how it is used, such as when delivered in relation to a Xaml element with custom scaling. To support these scenarios we use doubles.