DxfContourStudio

Industrial DXF contour analysis, diagnostics and repair workbench built with C# / .NET 10 / WPF.

Open a DXF, inspect and analyze contours, repair small gaps, save projects, and export cleaned DXF files — all in a bilingual (zh-CN / en-US) desktop UI.

中文 README

Status: v0.2.0 — first public functional release.

Overview

DxfContourStudio turns raw DXF geometry into a topology graph, recognizes open and closed contours, classifies nesting (outer / hole / island), finds geometry defects (gaps, open ends, branches, duplicates, zero-length runs, self intersections) and lets you repair the safe ones with full undo support. It is a pre-production geometry workbench — not a full CAD/CAM system.

Features

• DXF import (ACadSharp 3.6.51, MIT): LINE, ARC, CIRCLE, LWPOLYLINE (with bulges), POLYLINE/Vertex2D; ellipses/splines/INSERT/text are counted and reported, never crash. Coordinates canonicalized to millimeters.
• CAD viewport: pan / zoom, click-pick, selection highlight, layer visibility, drag-move with undo.
• Topology & contours: topology graph → chains → contours (length, bounds, signed area, orientation) → nesting (Outer / Hole / Island + depth).
• Diagnostics: small repairable gaps, open endpoints, branch nodes, zero-length geometry, very small geometry, duplicates (incl. reversed), line-line self intersections; severity model (Info / Warning / Error).
• Repair: single-gap repair (midpoint strategy) and batch "repair all safe gaps" — one composite undo restores the whole batch.
• Project format .dxfstudio (JSON): lossless save/load of geometry, layers, units and tolerance settings; dirty-state tracking and an unsaved-changes guard.
• Clean DXF export: writes LINE/ARC/CIRCLE/LWPOLYLINE (+ bulge) with configurable units and version; refuses to overwrite the source file by default; export report in the status bar.
• Export / re-import round-trip regression coverage: a repaired file stays repaired after export and re-import.
• Localization: zh-CN and en-US, persisted.
• Performance: near-linear topology and diagnostics (50k entities analyze in seconds).

Screenshots

Screenshots will be added after the first public release.

Supported DXF Entities

DXF entity	Support
LINE	full
ARC	full
CIRCLE	full
LWPOLYLINE (with bulges)	full
POLYLINE / Vertex2D	full
ELLIPSE, SPLINE, INSERT, TEXT/MTEXT	counted + reported, geometry skipped

Contour Analysis

• Topology-based chain building (shared endpoints collapse into nodes).
• Closed contour detection incl. implicit closing edges for closed polylines.
• Open / closed classification; outer / hole / island nesting with depth.
• Per-contour length, bounds, signed area and orientation.

Diagnostics & Repair

• Small gap (≤ repair tolerance) → repairable; both ends move to the midpoint.
• Open endpoints without a matching end → "no matching endpoint" (never a numeric sentinel).
• Branch nodes, zero-length entities, very small entities, duplicates (incl. reversed lines), line-line self intersections.
• Single repair and "repair all safe gaps" (one undo restores the batch).

Project Save / Load

• .dxfstudio JSON format, schema version 1.
• Lossless geometry round-trip (Line / Arc / Circle / Polyline incl. arc segments), layers, units and tolerance settings.
• Dirty-state indicator and unsaved-changes guard on open / open-project / exit.

Clean DXF Export

• LINE / ARC / CIRCLE / LWPOLYLINE (+ bulge) output.
• Configurable output unit (default: source unit, mm supported) and DXF version (R12 / R2000 / R2010 / R2018, default R2018).
• Never overwrites the source file unless explicitly allowed.

Architecture

src/DxfContourStudio.Core         pure geometry / topology — no WPF, no DXF
src/DxfContourStudio.Dxf          ACadSharp adapter (read + write), library-free contracts
src/DxfContourStudio.Application  documents, import/export, projects, commands, selection
src/DxfContourStudio.Wpf          WPF UI only (MVVM, CommunityToolkit.Mvvm)

See docs/ARCHITECTURE.md and docs/ADR/ for details.

Quick Start

Requirements:

• Windows 10/11
• .NET 10 SDK (see global.json)
• Visual Studio 2022 (optional)

Clone and build:

git clone <repo-url>
cd DxfContourStudio
dotnet restore DxfContourStudio.sln
dotnet build DxfContourStudio.sln -c Release
dotnet test  DxfContourStudio.sln -c Release
dotnet run --project src/DxfContourStudio.Wpf

Build

dotnet restore DxfContourStudio.sln
dotnet build DxfContourStudio.sln -c Debug      # 0 warnings / 0 errors
dotnet build DxfContourStudio.sln -c Release

Tests

• tests/DxfContourStudio.Core.Tests — geometry, topology, contours, intersection, diagnostics math.
• tests/DxfContourStudio.Dxf.Tests — import mapping, unit conversion, bulge.
• tests/DxfContourStudio.Application.Tests — documents, commands, projects, export round-trip, golden corpus, view-model integration, STA offscreen render regression.

Current baseline: 369 tests passing (Debug + Release, 0 warnings / 0 errors). See docs/TESTING.md.

Test Corpus

testdata/dxf/ holds a hand-authored regression corpus (19 files) covering rectangles, nesting, gaps, branches, duplicates, self intersections, polylines with bulges, mixed layers and unitless files. See docs/TEST_CORPUS.md.

Known Limitations

• Self-intersection analysis covers line/arc/polyline runs; tangent touches are intentionally not reported as intersections.
• R12 export is offered but not yet manually exercised end-to-end.
• This is not a complete CAD/CAM system: no Offset / Fillet / Chamfer, no machine / laser / PLC / GCode integration.

Roadmap

See docs/ROADMAP.md.

License

Apache-2.0 — see LICENSE.