transition_camera.gd

extends Camera2D


const SCREEN_SIZE := Vector2( 320, 180 )
var cur_screen := Vector2( 0, 0 )

func _ready():
	set_as_toplevel( true )
	global_position = get_parent().global_position
	_update_screen( cur_screen )

func _physics_process(delta):
	var parent_screen : Vector2 = ( get_parent().global_position / SCREEN_SIZE ).floor()
	if not parent_screen.is_equal_approx( cur_screen ):
		_update_screen( parent_screen )


func _update_screen( new_screen : Vector2 ):
	cur_screen = new_screen
	global_position = cur_screen * SCREEN_SIZE + SCREEN_SIZE * 0.5

This is a Camera2D that snaps into positions in a grid if its parent moves to a given cell.
Important to notice are:
line 8: setting the camera as "toplevel" to decouple its position from its parent
line 13: compute the position of the parent normalized and floored to the screen size (same as grid size)
lines 18-20: this function updates the camera position. It can also be used to call signals to activate objects (e.g. enemies) depending on the active grid cell.

btw in godot 4 instead of "set_as_toplevel( true )" idk why they added an extra "_"
so now its set_as_top_level( true ) lol

btw in godot 4 instead of "set_as_toplevel( true )" idk why they added an extra "_"
so now its set_as_top_level( true ) lol

Could also do top_level = true

using Godot;

public partial class TransitionCamera : Camera2D 
{
	private Vector2 ScreenSize => GetViewportRect().Size;
	
	private Vector2 current = new(0, 0);

	public override void _Ready()
	{
		this.TopLevel = true;
		this.GlobalPosition = GetParent<Node2D>().GlobalPosition;
		UpdateScreen(this.current);
	}

	public override void _PhysicsProcess(double delta)
	{
		Vector2 parentScreen = ( GetParent<Node2D>().GlobalPosition / this.ScreenSize ).Floor();
		if (!parentScreen.IsEqualApprox(this.current))
			UpdateScreen(parentScreen);
	}
	
	private void UpdateScreen(Vector2 newScreen) 
	{
		this.current = newScreen;
		this.GlobalPosition = current * this.ScreenSize + this.ScreenSize * 0.5f;
	}
}

Translation to C# for Godot 4