Incorrect window behaviour with scaling setting on

[Crimonit]

Issue: window placement acts incorrectly while dragging it with mouse on a scaled display

Steps to recreate:

1. Enable display scaling setting in Windows Settings, change it from 100% to any higher number
2. Drag the window by the top using mouse pointer
3. Window is now displaced, with the top being way lower than it should

[ErrorFlynn]

This happens because the application uses a type of DPI awareness that causes it to use the scale factor in effect when it was started (the application is not notified of any subsequent changes). That means that if you change the scale factor or move the application window to a monitor with a different scale factor, the application will not be aware of the change and continue to behave as if the scale factor in use when it started hasn't changed.

This is called "System DPI awareness" because the system manages the scaling when the DPI changes (by scaling the window's graphics buffer, like you would scale a bitmap), and the program uses it because it's compatible with Windows 7. The displacement you experience happens because you have Settings->Interface->Snap windows to screen edges checked, which uses code that scales a value with the system scale factor that was in use at program startup.

This situation is unlikely to change for a long time (I have other priorities for now), so there are two workarounds you can choose from. Either restart the application after you change the scale factor (preferable, because it also fixes window centering), or don't use "Snap windows to screen edges".