# Module Reference

This file provides a mapping of modules to their primary responsibilities and key symbols.

## Root

- `__init__.py`:
    - **Entry Point**: Extension registration (`register`, `unregister`).
    - **Node Tree**: `SLICETREE_NodeTree` class.
    - **Sockets**: Definitions for all `SLICESOCK_*` classes.
    - **Nodes**: Definitions for all `SLICENODE_*` classes.
    - **Evaluation Engine**: 
        - `resolve_input()`: Recursively evaluates linked sockets.
        - `_resolve_output()`: Computes node outputs with a caching system (`_EvalCache`) to avoid redundant calculations.
        - `_follow_reroute()`: Handles Blender's Reroute nodes during evaluation.

- `registry.py`: 
    - **Auto-Registration**: Utility to track classes decorated with `@register_class`.

- `blender_manifest.toml`: 
    - Metadata for the Blender Extension platform.

- `pyproject.toml`: 
    - Standard Python project configuration.

## `/core` (Geometry & Slicing)

- `slice.py`:
    - `slice_at_range()`: Top-level slicing function that iterates through Z-heights.
    - `slice_at_z()`: Vectorized plane-mesh intersection using NumPy.
    - `align_path_seam_sharpest()`: High-performance vectorized heuristic that positions the start vertex (seam) of closed polygon loops at the sharpest concave angle (inner corner), with fallback to sharpest angle overall.
    - `SlicePaths.align_seams()`: Method on `SlicePaths` to align path seams to sharpest concave angles while preserving per-vertex attributes and metadata.
    - `Pather`: Class that converts toolpaths into G-code strings. Supports per-segment extrusion rates, feedrates, and custom extra attributes.
    - `segments_to_slice()`: Utility to convert raw intersection segments into continuous paths (closed polygons are processed via Pyclipper, open paths remain open).
    - `link_segments()`: Logic for joining loose segments into continuous paths.
    - `buffer_slice()`: Offset utility using PyclipperOffset. Supports rotated offsetting.
    - `infill_slice()`: Generates rotated grid or rectilinear infill patterns, ensuring layer-to-layer consistency.
    - `boolean_slice()`: Performs 2D boolean operations (Union, Intersection, etc.) on slice sets.

- `geometry.py`:
    - Geometry utility functions.

## `/core/pdf_exporter` (PDF Export & Technical Marking Engine)

- `sa2_measures.py`:
    - `render_sa2_measures_pdf()`: ISO 129-1 technical marking engine.
    - `extract_slicing_object_features()`: Feature detection for circular bores (Ø), arcs (R), chamfers (C), and steps.
- `writer.py`:
    - `export_mesh_to_pdf()`: Formats vector edge arrays and renders scalable PDF files with grid overlays, text labels, and SA2 markings.

## `/infra` (Blender Integration)

- `blender_mesh_capture.py`:
    - `PdfProperties`: Dataclass holding PDF line width and line color attributes for a `SlicingObject`.
    - `SlicingObject`: Represents a single mesh as a NumPy triangle array.
    - `capture_mesh_edges()`: Extracts edges from a Blender mesh for path-based workflows. Supports capturing extra per-vertex attributes.

- `blender_slice_nodes_generic.py`:
    - Base classes for NodeSlicer nodes (`SliceNode`) and sockets (`SliceNodeSocket`).
    - Core evaluation logic (`resolve_input`).