Engine-Pong/Game/Behaviours/ShapeBehaviour.cs

using System.Collections.Generic;

using Microsoft.Xna.Framework;

using Apos.Shapes;

using Syntriax.Engine.Core;
using Syntriax.Engine.Core.Abstract;
using Syntriax.Engine.Physics2D.Primitives;

namespace Pong.Behaviours;

public class ShapeBehaviour : BehaviourOverride, IDisplayableShape
{
    private readonly List<Vector2D> vectors = [];
    private readonly static Vector2D screenScale = Vector2D.Down + Vector2D.Right;

    public ShapeBehaviour(Shape Shape) { this.Shape = Shape; }
    public ShapeBehaviour(Shape Shape, float Thickness) { this.Shape = Shape; this.Thickness = Thickness; }
    public ShapeBehaviour(Shape Shape, Color color) { this.Shape = Shape; Color = color; }
    public ShapeBehaviour(Shape Shape, Color color, float Thickness) { this.Shape = Shape; this.Thickness = Thickness; Color = color; }

    public Shape Shape { get; } = default!;
    public Color Color { get; set; } = Color.White;
    public float Thickness { get; set; } = .5f;

    public void Draw(ShapeBatch shapeBatch)
    {
        Shape.TransformShape(GameObject.Transform, vectors);
        for (int i = 0; i < vectors.Count; i++)
            vectors[i] = vectors[i].Scale(screenScale);

        for (int i = 0; i < vectors.Count - 1; i++)
            shapeBatch.DrawLine(vectors[i].ToVector2(), vectors[i + 1].ToVector2(), Thickness, Color, Color);
        shapeBatch.DrawLine(vectors[0].ToVector2(), vectors[^1].ToVector2(), Thickness, Color, Color);
    }
}

public static class ShapeTransform
{
    public static void TransformShape(this Shape shape, ITransform transform, List<Vector2D> vectors)
    {
        vectors.Clear();

        int count = shape.Vertices.Count;
        for (int i = 0; i < count; i++)
            vectors.Add(transform.TransformVector2D(shape[i]));
    }
}