Pong/Scripts/Managers/ScalingManager.cs

namespace Pong.Scripts.Managers;

public partial class ScalingManager : Node
{
    private HFlowContainer _score;
    private RigidBody2D _paddle;
    private CharacterBody2D _ball;

    private Area2D _leftWall;
    private Area2D _rightWall;
    private StaticBody2D _topWall;
    private StaticBody2D _bottomWall;

    private RigidBody2D _enemy;

    private Vector2I _gameResolution;
    private Vector2 _edgePosition;

    public override void _EnterTree()
    {
        GetNodes();
        GetTree().Root.SizeChanged += AdaptToGameResolution;
        AdaptToGameResolution();
    }

    public override void _ExitTree()
    {
        GetTree().Root.SizeChanged -= AdaptToGameResolution;
    }

    /// <summary>
    /// a method that gets all the nodes that the scaling manager will manage the position and scale of.
    /// </summary>
    private void GetNodes()
    {
        _score = GetNode<HFlowContainer>("../Score");
        _paddle = GetNode<RigidBody2D>("../Paddle");
        _ball = GetNode<CharacterBody2D>("../Ball");

        _leftWall = GetNode<Area2D>("../Walls/Left");
        _rightWall = GetNode<Area2D>("../Walls/Right");
        _topWall = GetNode<StaticBody2D>("../Walls/Top");
        _bottomWall = GetNode<StaticBody2D>("../Walls/Bottom");

        _enemy = GetNode<RigidBody2D>("../Enemy");
    }

    /// <summary>
    /// adapt to the current resolution of the game.
    /// </summary>
    private void AdaptToGameResolution()
    {
        _gameResolution = DisplayServer.WindowGetSize();
        _edgePosition = CalculateEdgePosition(_gameResolution);

        SetWallPosition();
        SetScorePosition();
    }

    /// <summary>
    /// calculate the edges of the screen according to 0, 0 being in the center of the screen.
    /// </summary>
    private static Vector2 CalculateEdgePosition(Vector2 resolution)
    {
        return new Vector2(resolution.X / 2, resolution.Y / 2);
    }

    /// <summary>
    /// set the position and scale of the walls according to the edge position.
    /// </summary>
    private void SetWallPosition()
    {
        var xSize = _edgePosition.X - Constants.WallSizeExtents;
        var ySize = _edgePosition.Y - Constants.WallSizeExtents;

        _leftWall.Position = new Vector2(-xSize, 0);
        _rightWall.Position = new Vector2(xSize, 0);
        _topWall.Position = new Vector2(0, -ySize);
        _bottomWall.Position = new Vector2(0, ySize);

        _leftWall.Scale = _leftWall.Scale with { Y = _gameResolution.Y };
        _rightWall.Scale = _rightWall.Scale with { Y = _gameResolution.Y };
        _topWall.Scale = _topWall.Scale with { X = _gameResolution.X - 60 };
        _bottomWall.Scale = _bottomWall.Scale with { X = _gameResolution.X - 60 };
    }

    /// <summary>
    /// set the position of the score ui. this has to be calculated with 0, 0 being the top left of the screen as
    /// the UI's point starts from there instead of the point being in the middle of the screen.
    /// </summary>
    private void SetScorePosition()
    {
        _score.Position = new Vector2(-_edgePosition.X + 30, -_edgePosition.Y + 30);
        _score.Size = new Vector2(_gameResolution.X - 60, _gameResolution.Y - 60);
    }
}