Чтение файлов и внешних ресурсов

using System.Text;
using Reckfell;

public partial class FileDemo : Entity
{
    public const string Folder = "user://io-demo";
    public const string Note = Folder + "/message.txt";
    public const int MaxBytes = 1024 * 1024;
    private static readonly UTF8Encoding Utf8 = new(false, true);

    public static Error WriteNote(string text) => WriteText(Note, text);

    public static Error WriteText(string path, string text)
    {
        try
        {
            if (Utf8.GetByteCount(text) > MaxBytes)
                return Error.OutOfMemory;
        }
        catch (EncoderFallbackException)
        {
            return Error.InvalidData;
        }
        Error error = DirAccess.MakeDirRecursiveAbsolute(path.GetBaseDir());
        if (error != Error.Ok)
            return error;
        using var file = FileAccess.Open(path, FileAccess.ModeFlags.Write);
        if (file is null)
            return FileAccess.GetOpenError();
        return file.StoreString(text) ? file.GetError() : Error.FileCantWrite;
    }

    public static Error ReadText(string path, out string text)
    {
        text = "";
        using var file = FileAccess.Open(path, FileAccess.ModeFlags.Read);
        if (file is null)
            return FileAccess.GetOpenError();
        ulong length = file.GetLength();
        if (length > MaxBytes)
            return Error.OutOfMemory;
        byte[] bytes = file.GetBuffer((long)length);
        if ((ulong)bytes.Length != length)
            return Error.FileCorrupt;
        try
        {
            text = Utf8.GetString(bytes);
            return Error.Ok;
        }
        catch (DecoderFallbackException)
        {
            return Error.InvalidData;
        }
    }

    public override void _Ready()
    {
        Error error = WriteNote("Reckfell: привет\nSecond line");
        if (error == Error.Ok)
        {
            error = ReadText(Note, out string text);
            if (error == Error.Ok)
                ReckfellApi.Print(text);
        }
        ReckfellApi.Print($"File demo: {error}");
    }
}

using Reckfell;

public partial class ExternalPreview : Entity
{
    [Export] public string ImagePath { get; set; } = "user://io-demo/preview.png";
    [Export] public TextureRect Target { get; set; } = null!;
    [Export] public bool WithMipmaps { get; set; }

    public override void _Ready() => ReckfellApi.Print(Reload());

    public Error Reload()
    {
        if (!ReckfellObject.IsInstanceValid(Target))
            return Error.Unconfigured;
        if (!FileAccess.FileExists(ImagePath))
            return Error.FileNotFound;
        using var image = new Image();
        Error error = image.Load(ImagePath);
        if (error != Error.Ok)
            return error;
        if (WithMipmaps)
        {
            error = image.GenerateMipmaps();
            if (error != Error.Ok)
                return error;
        }
        ImageTexture texture = ImageTexture.CreateFromImage(image);
        Target.Texture = texture;
        return Error.Ok;
    }
}