Weird signal triggering behavior with PolygonCollision2D

Help Programming
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1

Godot Version

v4.3.stable.official.77dcf97d8 (Linux Mint 22.1)

Question

Hi

There is a polygon collision 2d component in my project. This component is reshaped every frame via code according to the area scanned by the mouse. Plus (0, 0) to form a complete triangle. (So when my mouse is at coordinates 5-15 in the first frame and 20-50 in the second frame, the shape of the polygon in the second frame is like this: (5, 15), (20, 50), (0, 0))

In this way, I try to detect whether the mouse is touching anything between two frames, even with fast movements. The idea is not pretty bad, but in practice, Signals cause some weird problems.

Normally when I enter and exit the obstacle with my mouse cursor the signal should be triggered but most of the time it is not. After some long long experiments I noticed that if I keep the mouse cursor still on the obstacle the signal is triggered every few seconds. I couldn’t notice a pattern but that’s all I know.

(@tool mode)
(@tool mode)1245×726 105 KB

extends Area2D

var pos : Vector2
var pos_prev : Vector2


func _process(delta: float) -> void:
	pos = get_global_mouse_position()
	
	%CollisionPolygon2D.polygon[0] = Vector2(0, 0)
	%CollisionPolygon2D.polygon[1] = pos
	%CollisionPolygon2D.polygon[2] = pos_prev
	pos_prev = pos


func _on_area_entered(area: Area2D) -> void:
	print("Collided!")

I’ve been working on this problem for a day and tried every solution I could find regarding Area2D and Collisions but can’t get a logical result.

2

You should try changing the polygon in the physics process. Who knows what the physics server is doing when you change the collision shape.

3

Thank you so much