inabox/inabox.dxf/DxfUtils.cs

using System.Drawing;
using System.Drawing.Drawing2D;
using InABox.Core;
using netDxf;
using netDxf.Entities;
using netDxf.Objects;
using netDxf.Tables;
using Point = System.Drawing.Point;

namespace InABox.Dxf;

public class DxfImportSettings
{
    public Size ImageSize;

    public string[]? SupportFolders;

    public string? LayoutName { get; set; }

    public DxfImportSettings(Size? imageSize = null, string[]? supportFolders = null, string? layoutName = null)
    {
        ImageSize = imageSize ?? new(2048, 2048);
        SupportFolders = supportFolders;
        LayoutName = layoutName;
    }
}

public class DxfData
{
    public DxfDocument Document { get; set; }

    public DxfImportSettings Settings { get; set; }

    public SizeF Size { get; set; }

    public PointF Origin { get; set; }

    public Layout Layout { get; set; }

    public IEnumerable<string> LayoutNames => Document.Layouts.Select(x => x.Name);

    public HashSet<string>? Layers { get; set; }

    public bool HasLayer(Layer layer)
    {
        return Layers is null || Layers.Contains(layer.Name);
    }

    public void SetLayers(params string[] layers)
    {
        Layers = layers.ToHashSet();
    }
    public void SetLayers(IEnumerable<string> layers)
    {
        Layers = layers.ToHashSet();
    }

    public bool ShouldDraw(EntityObject obj)
    {
        return obj.IsVisible && HasLayer(obj.Layer);
    }

    public string LayoutName
    {
        get => Layout.Name;
        set
        {
            Layout = Document.Layouts.First(x => x.Name == value);
            Size = new((float)(Layout.MaxLimit.X - Layout.MinLimit.X), (float)(Layout.MaxLimit.Y - Layout.MinLimit.Y));
            Origin = new((float)Layout.MinLimit.X, (float)Layout.MinLimit.Y);
        }
    }

    public DxfData(DxfDocument document, DxfImportSettings settings)
    {
        Document = document;
        Settings = settings;

        Layout = settings.LayoutName is not null ? document.Layouts.First(x => x.Name == settings.LayoutName) : document.Layouts.First();
        Size = new((float)(Layout.MaxLimit.X - Layout.MinLimit.X), (float)(Layout.MaxLimit.Y - Layout.MinLimit.Y));
        Origin = new((float)Layout.MinLimit.X, (float)Layout.MinLimit.Y);
    }
}

public static class DxfUtils
{
    public static event ProcessError OnProcessError;
    public delegate void ProcessError(string message);

    internal static IDxfObject? ConvertEl(EntityObject el)
    {
        if(el is Line line)
        {
            return new DxfLine { Line = line };
        }
        else if(el is Insert insert)
        {
            return new DxfInsert(insert);
        }
        else if(el is Ellipse ellipse)
        {
            return new DxfEllipse(ellipse);
        }
        else if(el is MText text)
        {
            return new DxfMText(text);
        }
        else if(el is Polyline2D ln2D)
        {
            return new DxfPolyline2D(ln2D);
        }
        else if(el is Dimension dim)
        {
            return new DxfDimension(dim);
        }
        else if(el is Solid solid)
        {
            return new DxfSolid(solid);
        }
        else if (el is netDxf.Entities.Point point)
        {
            return null;
        }
        else
        {
            return null;
        }
    }

    public static void DrawDxf(DxfData data, Graphics graphics)
    {
        // Calculate the scaling factor to fit the image within the bounds
        float ratioX = (float)data.Settings.ImageSize.Width / data.Size.Width;
        float ratioY = (float)data.Settings.ImageSize.Height / data.Size.Height;

        var scale = Math.Min(ratioX, ratioY);

        var drawData = new DrawData() { Graphics = graphics, Data = data };

        Brush _brush = new SolidBrush(Color.White);
        graphics.FillRectangle(_brush, 0, 0, graphics.VisibleClipBounds.Width, graphics.VisibleClipBounds.Height);

        // drawData.Translate(graphics.VisibleClipBounds.Width / 2, graphics.VisibleClipBounds.Height / 2);

        drawData.Scale(scale, scale);
        drawData.Translate(-data.Origin.X, -data.Origin.Y);
        // drawData.Translate(-data.Origin.X - data.Size.Width / 2, -data.Origin.Y - data.Size.Height / 2);

        foreach(var el in data.Document.Entities.All)
        {
            var item = ConvertEl(el);
            item?.Draw(drawData);
        }
    }

    public static DxfData LoadDxf(string filename, DxfImportSettings? settings = null)
    {
        using var stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
        settings ??= new();

        var document = DxfDocument.Load(stream, settings.SupportFolders ?? Array.Empty<string>());
        document.BuildDimensionBlocks = true;
        return new(document, settings);
    }
    public static DxfData LoadDxf(Stream stream, DxfImportSettings? settings = null)
    {
        settings ??= new();

        var document = DxfDocument.Load(stream, settings.SupportFolders ?? Array.Empty<string>());
        return new(document, settings);
    }

    /// <summary>
    /// Returns <see langword="null"/> if the bounds are completely empty.
    /// </summary>
    /// <param name="data"></param>
    /// <returns></returns>
    public static RectangleF? CalculateDxfSize(DxfData data)
    {
        var transformData = new TransformData { Data = data };

        RectangleF? bounds = null;
        foreach(var el in data.Document.Entities.All)
        {
            if(ConvertEl(el) is IDxfObject obj)
            {
                bounds = Utils.CombineBounds(bounds, obj.GetBounds(transformData));
            }
        }
        return bounds;
    }

    public static Bitmap ProcessImage(DxfData data)
    {
        var height = data.Size.Height;
        var width = data.Size.Width;
        
        // Calculate the scaling factor to fit the image within the bounds
        float ratioX = (float)data.Settings.ImageSize.Width / width;
        float ratioY = (float)data.Settings.ImageSize.Height / height;

        var scale = Math.Min(ratioX, ratioY);

        var _result = new Bitmap((int)(width * scale), (int)(height * scale));
        using (var _graphics = Graphics.FromImage(_result))
        {
            _graphics.SmoothingMode = SmoothingMode.AntiAlias;
            DrawDxf(data, _graphics);
        }
        _result.RotateFlip(RotateFlipType.RotateNoneFlipY);

        return _result;
    }

    public static Bitmap ProcessImage(Stream stream, DxfImportSettings? settings = null)
    {
        return ProcessImage(LoadDxf(stream, settings));
    }

    public static Result<Bitmap, Exception> DXFToBitmap(string filename, DxfImportSettings? settings = null)
    {
        using var stream = new FileStream(filename, FileMode.Open, FileAccess.Read);
        try
        {
            return Result.Ok(ProcessImage(stream, settings: settings));
        }
        catch (Exception e)
        {
            OnProcessError?.Invoke(e.Message);
            return Result.Error(e);
        }
    }
}