Environment: Windows 10 Pro 64bit, Chrome, Godot 3.0.2, GDScript
Capturing the mouse must be done in an input handler like
_input on HTML5 due to browser security restrictions. (See
https://godotengine.org/qa/25058/what-is-the-proper-way-of-capturing-the-mouse-in-a-html5-game for more details.)
While the mouse is captured the following code is used to integrate (aggregate) the relative mouse movements:
if event is InputEventMouseMotion:
aggregated_mouse_delta += event.relative
It works fine on desktop, but on HTML5
event.relative seems to be zero all the time.
Where the relative movement vector is saved while the mouse is captured in a HTML5 game?