feat: add DrawingDxfExporter to convert PEP Drawing to DXF stream

PepApi.sln

@@ -9,6 +9,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PepLib.Core", "PepLib.Core\
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PepMcp", "PepMcp\PepMcp.csproj", "{28899B7B-2185-4141-B348-E227DFB355E9}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PepLib.Core.Tests", "PepLib.Core.Tests\PepLib.Core.Tests.csproj", "{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -55,6 +57,18 @@ Global
 		{28899B7B-2185-4141-B348-E227DFB355E9}.Release|x64.Build.0 = Release|Any CPU
 		{28899B7B-2185-4141-B348-E227DFB355E9}.Release|x86.ActiveCfg = Release|Any CPU
 		{28899B7B-2185-4141-B348-E227DFB355E9}.Release|x86.Build.0 = Release|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Debug|x64.Build.0 = Debug|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Debug|x86.Build.0 = Debug|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Release|Any CPU.Build.0 = Release|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Release|x64.ActiveCfg = Release|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Release|x64.Build.0 = Release|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Release|x86.ActiveCfg = Release|Any CPU
+		{FF7E4CB2-8825-4A03-9D0C-CC713BD93A18}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

PepLib.Core.Tests/IO/DrawingDxfExporterTests.cs

@@ -0,0 +1,63 @@
+using PepLib.Codes;
+using PepLib.Enums;
+using PepLib.Geometry;
+using PepLib.IO;
+using PepLib.Models;
+using Xunit;
+
+namespace PepLib.Core.Tests.IO;
+
+public class DrawingDxfExporterTests
+{
+    [Fact]
+    public void Export_RectangularLoop_ProducesFourLines()
+    {
+        // Arrange: a square 10x10 in incremental mode
+        var drawing = new Drawing();
+        drawing.Info = new DrawingInfo { Name = "TEST" };
+        var loop = new Loop { Name = "TEST.loop-000" };
+        // Mode defaults to Incremental in Loop constructor
+        loop.Add(new RapidMove(new Vector(0, 0)));   // position at (0,0)
+        loop.Add(new LinearMove(new Vector(10, 0)));  // → (10,0)
+        loop.Add(new LinearMove(new Vector(0, 10)));  // → (10,10)
+        loop.Add(new LinearMove(new Vector(-10, 0))); // → (0,10)
+        loop.Add(new LinearMove(new Vector(0, -10))); // → (0,0)
+        drawing.Loops.Add(loop);
+
+        // Act
+        using var stream = DrawingDxfExporter.Export(drawing);
+
+        // Assert: stream is non-empty and contains 4 line entities
+        Assert.True(stream.Length > 0);
+
+        stream.Position = 0;
+        using var reader = new ACadSharp.IO.DxfReader(stream);
+        var doc = reader.Read();
+        var lines = doc.Entities.OfType<ACadSharp.Entities.Line>().ToList();
+        var arcs = doc.Entities.OfType<ACadSharp.Entities.Arc>().ToList();
+        Assert.Equal(4, lines.Count);
+        Assert.Empty(arcs);
+    }
+
+    [Fact]
+    public void Export_LoopWithArc_ProducesLineAndArc()
+    {
+        var drawing = new Drawing();
+        drawing.Info = new DrawingInfo { Name = "TEST" };
+        var loop = new Loop { Name = "TEST.loop-000" };
+        loop.Add(new RapidMove(new Vector(5, 0)));                              // start at (5,0)
+        loop.Add(new LinearMove(new Vector(5, 0)));                             // → (10,0)
+        loop.Add(new CircularMove(new Vector(-5, 5), new Vector(-5, 0), RotationType.CCW)); // arc: end=(5,5), center=(5,0)
+        drawing.Loops.Add(loop);
+
+        using var stream = DrawingDxfExporter.Export(drawing);
+
+        stream.Position = 0;
+        using var reader = new ACadSharp.IO.DxfReader(stream);
+        var doc = reader.Read();
+        var lines = doc.Entities.OfType<ACadSharp.Entities.Line>().ToList();
+        var arcs = doc.Entities.OfType<ACadSharp.Entities.Arc>().ToList();
+        Assert.Single(lines);
+        Assert.Single(arcs);
+    }
+}

PepLib.Core.Tests/PepLib.Core.Tests.csproj

@@ -0,0 +1,23 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="ACadSharp" Version="3.1.32" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\PepLib.Core\PepLib.Core.csproj" />
+  </ItemGroup>
+
+</Project>

PepLib.Core/IO/DrawingDxfExporter.cs

@@ -0,0 +1,106 @@
+using ACadSharp;
+using ACadSharp.IO;
+using ACadSharp.Tables;
+using CSMath;
+using PepLib.Codes;
+using PepLib.Enums;
+using PepLib.Geometry;
+using PepLib.Models;
+using AcadArc = ACadSharp.Entities.Arc;
+using AcadCircle = ACadSharp.Entities.Circle;
+using AcadLine = ACadSharp.Entities.Line;
+
+namespace PepLib.IO;
+
+public static class DrawingDxfExporter
+{
+    public static Stream Export(Drawing drawing)
+    {
+        var doc = new CadDocument();
+
+        foreach (var loop in drawing.Loops)
+        {
+            var layer = new Layer(loop.Name);
+            doc.Layers.Add(layer);
+
+            var pos = new Vector();
+
+            foreach (var code in loop)
+            {
+                switch (code.CodeType())
+                {
+                    case CodeType.RapidMove:
+                        pos = Advance(pos, ((RapidMove)code).EndPoint, loop.Mode);
+                        break;
+
+                    case CodeType.LinearMove:
+                        var lm = (LinearMove)code;
+                        var lineEnd = Advance(pos, lm.EndPoint, loop.Mode);
+                        doc.Entities.Add(new AcadLine
+                        {
+                            StartPoint = ToXYZ(pos),
+                            EndPoint = ToXYZ(lineEnd),
+                            Layer = layer
+                        });
+                        pos = lineEnd;
+                        break;
+
+                    case CodeType.CircularMove:
+                        var cm = (CircularMove)code;
+                        var arcEnd = Advance(pos, cm.EndPoint, loop.Mode);
+                        var arcCenter = Advance(pos, cm.CenterPoint, loop.Mode);
+
+                        var dx = pos.X - arcCenter.X;
+                        var dy = pos.Y - arcCenter.Y;
+                        var radius = Math.Sqrt(dx * dx + dy * dy);
+
+                        var startAngle = Math.Atan2(pos.Y - arcCenter.Y, pos.X - arcCenter.X);
+                        var endAngle = Math.Atan2(arcEnd.Y - arcCenter.Y, arcEnd.X - arcCenter.X);
+
+                        if (cm.Rotation == RotationType.CW)
+                        {
+                            (startAngle, endAngle) = (endAngle, startAngle);
+                        }
+
+                        if (Math.Abs(startAngle - endAngle) < 1e-10) // full circle
+                        {
+                            doc.Entities.Add(new AcadCircle
+                            {
+                                Center = ToXYZ(arcCenter),
+                                Radius = radius,
+                                Layer = layer
+                            });
+                        }
+                        else
+                        {
+                            doc.Entities.Add(new AcadArc
+                            {
+                                Center = ToXYZ(arcCenter),
+                                Radius = radius,
+                                StartAngle = startAngle,
+                                EndAngle = endAngle,
+                                Layer = layer
+                            });
+                        }
+
+                        pos = arcEnd;
+                        break;
+                }
+            }
+        }
+
+        var buffer = new MemoryStream();
+        using (var writer = new DxfWriter(buffer, doc, false))
+        {
+            writer.Write();
+        }
+
+        var stream = new MemoryStream(buffer.ToArray());
+        return stream;
+    }
+
+    private static Vector Advance(Vector current, Vector offset, ProgrammingMode mode) =>
+        mode == ProgrammingMode.Incremental ? current + offset : offset;
+
+    private static XYZ ToXYZ(Vector v) => new XYZ(v.X, v.Y, 0);
+}

PepLib.Core/PepLib.Core.csproj

@@ -7,6 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="ACadSharp" Version="3.1.32" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.10">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>