OpenNest/CLAUDE.md

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

OpenNest is a Windows desktop application for CNC nesting — arranging 2D parts on material plates to minimize waste. It imports DXF drawings, places parts onto plates using rectangle-packing algorithms, and can export nest layouts as DXF or post-process them to G-code for CNC cutting machines.

Build

This is a .NET Framework 4.8 solution using legacy-style .csproj files (not SDK-style). Build with:

msbuild OpenNest.sln /p:Configuration=Release

NuGet dependency: netDxf (referenced via packages/ folder, not PackageReference). Restore with nuget restore OpenNest.sln if needed.

No test projects exist in this solution.

Architecture

Three projects form a layered architecture:

OpenNest.Core (class library)

Domain model and geometry primitives. Everything lives in the OpenNest namespace.

• Domain model: Nest → Plate[] → Part[] → Drawing → Program. A Nest is the top-level container. Each Plate has a size, material, quadrant, spacing, and contains placed Part instances. Each Part references a Drawing (the template) and has its own location/rotation. A Drawing wraps a CNC Program.
• CNC subsystem (CNC/): Program holds a list of ICode instructions (G-code-like: RapidMove, LinearMove, ArcMove, SubProgramCall). Programs support absolute/incremental mode conversion, rotation, offset, bounding box calculation, and cloning. This is the core geometric representation — parts are manipulated by transforming their Program.
• Geometry (Geometry/): Higher-level shapes (Line, Arc, Circle, Polygon, Shape) used for intersection detection, area calculation, and DXF conversion. ConvertProgram.ToGeometry() bridges from CNC codes to geometry entities.
• Quadrant system: Plates use quadrants 1-4 (like Cartesian quadrants) to determine coordinate origin placement. This affects bounding box calculation, rotation, and part positioning.

OpenNest.Engine (class library, depends on Core)

Nesting algorithms. NestEngine orchestrates filling plates with parts.

• RectanglePacking/: FillBestFit (single-item fill, tries horizontal and vertical orientations), PackBottomLeft (multi-item bin packing, sorts by area descending). Both operate on Bin/Item abstractions.
• CirclePacking/: Alternative packing for circular parts.
• NestItem: Input to the engine — wraps a Drawing with quantity, priority, and rotation constraints.
• BestCombination: Finds optimal mix of normal/rotated columns for grid fills.

OpenNest (WinForms WinExe, depends on Core + Engine)

The UI application with MDI interface.

• Forms/: MainForm (MDI parent), EditNestForm (MDI child per nest), plus dialogs for plate editing, auto-nesting, DXF conversion, cut parameters, etc.
• Controls/: PlateView (2D plate renderer with zoom/pan), DrawingListBox, DrawControl, QuadrantSelect.
• Actions/: User interaction modes — ActionSelect, ActionAddPart, ActionClone, ActionFillArea, ActionZoomWindow, ActionSetSequence.
• IO/: DxfImporter/DxfExporter (via netDxf library), NestReader/NestWriter (custom ZIP-based format with XML metadata + G-code programs), ProgramReader.
• Post-processing: IPostProcessor plugin interface loaded from DLLs in a Posts/ directory at runtime.

File Format

Nest files (.zip) contain:

• info — XML with nest metadata and plate defaults
• drawing-info — XML with drawing metadata (name, material, quantities, colors)
• plate-info — XML with plate metadata (size, material, spacing)
• program-NNN — G-code text for each drawing's cut program
• plate-NNN — G-code text encoding part placements (G00 for position, G65 for sub-program call with rotation)

Key Patterns

• All namespace roots are OpenNest (even OpenNest.Core uses namespace OpenNest).
• ObservableList<T> provides ItemAdded/ItemRemoved/ItemChanged events used for automatic quantity tracking between plates and drawings.
• Angles throughout the codebase are in radians (use Angle.ToRadians()/Angle.ToDegrees() for conversion).
• Tolerance.Epsilon is used for floating-point comparisons across geometry operations.