Godot v3.3.1.stable.mono.official
I am trying to draw a CollisionPolygon2D programmatically but I cannot resize or write the PoolVector2Array property called polygon:
extends CollisionPolygon2D func _ready() -> void: polygon.resize(1) print(polygon.size()) polygon[0] = Vector2.ZERO This code prints 0 and throws an error: Invalid set index '0' (on base: 'PoolVector2Array') with value of type 'Vector2'.
The type PoolVector2Array is a value type, and reading polygon gives you copy. Use another variable to hold it and edit it:
func _ready() -> void: var points = polygon points.resize(1) points[0] = Vector2.ZERO polygon = points print(polygon.size()) If you are going to build it over time, I suggest to add another field, and do the modifications to that field:
var _points := PoolVector2Array() func _ready() -> void: _points.resize(1) _points[0] = Vector2.ZERO polygon = _points print(polygon.size()) And you would be doing polygon = _points every time you need to commit the changes.
CanvasItem.material is also a value type? When a property refers to a more complex object than built-in types it gives access to it by a copy? Maybe you can ask and answer a question about that? \$\endgroup\$