BUG: Drawings from previous session persist on desktop after deactivation

[Arezhik]

Summary

When the user activates the overlay and makes drawings of any duration, those drawings remain stored in local memory after the overlay is deactivated (via hotkey). Upon reactivating the overlay, the previous drawings briefly reappear before being cleared from the canvas. The drawings are only fully removed when the overlay is activated again, at which point the canvas is finally reset being viewable by the user.

Expected Behavior

• As soon as the overlay is deactivated (hotkey pressed again), the entire drawing canvas should be cleared out from memory. If that is expected behavior.
• The next new activation of the overlay should start with a perfectly clean/transparent canvas.
• At no time should old drawings from previous sessions be visible on desktop when the new overlay is activated, even briefly. The clearing of the canvas should take place when the overlay is deactivated or before the overlay is displayed upon reactivation.

Actual Behavior

1. Activate overlay → draw anything (even a single stroke) → deactivate
   → Everything disappears, but is stored in local memory.
2. Reactivate the overlay later
   → Previous drawings are displayed briefly (250-500ms) before being removed off of the canvas. They are only removed after the activation of a new drawing session.

Steps to Reproduce

1. Start the app and activate the overlay (hotkey).
2. Draw a few lines or scribbles.
3. Deactivate the overlay (hotkey again).
4. Reactivate the overlay again. (hotkey again).
5. Observe step 1's drawing briefly appear again before being cleared.

Environment

• Windows 10
• Single monitor