namespace GameCli;

/// <summary>
/// Builds the 7-dim observation vector fed to PPO:
/// [dx, dy, vx, vy, sin(angle), cos(angle), angular_velocity]
/// Angle is encoded as sin/cos to avoid the discontinuity at ±π.
/// </summary>
public static class Observation
{
    public const int Dim = 7;

    public static float[] Build(ShipState s, (float X, float Y) target)
    {
        return new float[Dim]
        {
            target.X - s.X,
            target.Y - s.Y,
            s.VX,
            s.VY,
            MathF.Sin(s.Angle),
            MathF.Cos(s.Angle),
            s.AngularVelocity,
        };
    }
}