acadrust

A pure Rust library for reading and writing CAD files (DXF and DWG).

Inspired by ACadSharp. Supports DXF (ASCII & Binary) and DWG (R13–R2018).

Quick Start

[dependencies]
acadrust = "0.3.1"

use acadrust::{CadDocument, DxfReader, DxfWriter};

fn main() -> acadrust::Result<()> {
    // Read
    let doc = DxfReader::from_file("input.dxf")?.read()?;
    println!("{} entities", doc.entities().count());

    // Write
    let writer = DxfWriter::new(&doc);
    writer.write_to_file("output.dxf")?;
    Ok(())
}

Features

• DXF Read/Write — ASCII and Binary formats, R12–R2018+
• DWG Read/Write — Native binary, R13–R2018 (208/208 roundtrip-perfect)
• 41 Entity Types — Lines, arcs, polylines, hatches, dimensions, 3D solids, viewports, and more
• Tables & Objects — Layers, linetypes, styles, dictionaries, layouts, materials
• Serde Support — Optional Serialize/Deserialize for all types (features = ["serde"])
• Failsafe Mode — Error-tolerant parsing with structured diagnostics
• Encoding Support — ~40 code pages for pre-2007 files

File Version Support

Version	AutoCAD	DXF	DWG
AC1009	R12	✅	—
AC1012–AC1014	R13–R14	✅	✅
AC1015–AC1032	2000–2018+	✅	✅

Examples

DWG Read/Write

use acadrust::{CadDocument, DwgWriter};
use acadrust::io::dwg::DwgReader;
use acadrust::entities::*;
use acadrust::types::{Color, Vector3};

fn main() -> acadrust::Result<()> {
    // Read DWG
    let mut reader = DwgReader::from_file("drawing.dwg")?;
    let doc = reader.read()?;

    // Iterate entities
    for entity in doc.entities() {
        println!("{:?}", entity);
    }

    // Create & Write DWG
    let mut doc = CadDocument::new();
    let mut line = Line::from_coords(0.0, 0.0, 0.0, 100.0, 50.0, 0.0);
    line.common.color = Color::RED;
    doc.add_entity(EntityType::Line(line))?;
    DwgWriter::write_to_file("output.dwg", &doc)?;
    Ok(())
}

Paper Space Layouts & Viewports

use acadrust::{CadDocument, DxfVersion, DxfWriter};
use acadrust::entities::{EntityType, Viewport};
use acadrust::types::Vector3;

fn main() -> acadrust::Result<()> {
    let mut doc = CadDocument::with_version(DxfVersion::AC1027);

    // Add geometry to model space
    let line = acadrust::entities::Line::from_coords(0.0, 0.0, 0.0, 100.0, 100.0, 0.0);
    doc.add_entity(EntityType::Line(line))?;

    // Overall viewport (ID=1) for default Layout1
    let mut overall_vp = Viewport::new();
    overall_vp.id = 1;
    overall_vp.center = Vector3::new(148.5, 105.0, 0.0);
    doc.add_paper_space_entity(EntityType::Viewport(overall_vp))?;

    // Detail viewport using builder pattern
    let vp1 = Viewport::new()
        .with_center(Vector3::new(148.5, 105.0, 0.0))
        .with_view_target(Vector3::new(50.0, 50.0, 0.0))
        .with_scale(1.0)
        .with_locked();
    doc.add_paper_space_entity(EntityType::Viewport(vp1))?;

    // Create a second layout with its own viewport
    doc.add_layout("Layout2")?;
    let mut vp2 = Viewport::with_size(Vector3::new(200.0, 150.0, 0.0), 400.0, 300.0);
    vp2.id = 1;
    doc.add_entity_to_layout(EntityType::Viewport(vp2), "Layout2")?;

    DxfWriter::new(&doc).write_to_file("layouts.dxf")?;
    Ok(())
}

Serde / JSON

use acadrust::{CadDocument, DxfReader};

fn main() -> acadrust::Result<()> {
    let doc = DxfReader::from_file("drawing.dxf")?.read()?;
    let json = serde_json::to_string_pretty(&doc).unwrap();
    let doc2: CadDocument = serde_json::from_str(&json).unwrap();
    println!("Entities: {}", doc2.entities().count());
    Ok(())
}

Documentation

Full API docs: docs.rs/acadrust

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Changelog

0.3.1

• Entity explode — EntityType::explode() decomposes complex entities (polylines, hatches, meshes, dimensions, etc.) into simpler primitives (lines, arcs, faces); CadDocument::explode_entity() allocates handles automatically

• Centralized transform/mirror/translate — Transformation logic extracted from 38 entity files into translate.rs, transform.rs, and mirror.rs modules; all Entity trait implementations delegate to these centralized functions. Direct EntityType dispatch methods added (entity.translate(), entity.apply_transform(), entity.mirror_x(), etc.) alongside the existing trait-based API.

0.3.0

• ACI color support — Full 256-entry AutoCAD Color Index (ACI) to RGB lookup table, Color::rgb() resolves index colors, Color::approximate_index() finds nearest ACI match for true colors

• Hatch edge fix — Corrected hatch edge reading/writing issues

• LwPolyline bulge fix — Fixed bulge value handling in parser and writer

• Performance optimizations — Zero-allocation number formatting with itoa/ryu, buffered I/O, reduced memory allocations throughout DXF read/write pipeline. Parsing/writing speed are dramatically increased.

• Table entry deduplication — add_or_replace for table entries eliminates handle collisions during read

Breaking API change

• BlockRecord entity storage — BlockRecord now stores entity_handles: Vec<Handle> instead of owning entities directly. All entities live in flat storage inside CadDocument with O(1) handle-based lookup. If you accessed block entities directly, use doc.get_entity(handle) instead:

  // Before (0.2.x): iterating block entities directly
  // for entity in &block_record.entities { ... }
  
  // After (0.3.0): resolve handles through the document
  for &handle in &block_record.entity_handles {
      if let Some(entity) = doc.get_entity(handle) {
          // use entity
      }
  }

  The CadDocument public API (add_entity(), entities(), get_entity(), get_entity_mut()) is unchanged.

0.2.10

• Paper space & layout support — add_paper_space_entity(), add_entity_to_layout(), add_layout() API for creating viewports in multiple paper space layouts
• Correct DXF paper space structure — Active layout (*Paper_Space) entities in ENTITIES section with code 67; non-active layouts (*Paper_Space0, *Paper_Space1, …) entities inside BLOCK definitions
• AutoCAD AUDIT compatibility — Fixed code 67 paper space flag, MLineStyle angle conversion (radians→degrees), AcDbPlotSettings flag, viewport owner handles
• DXF reader — Proper handling of code 67 (paper space flag) in common entity parsing

0.2.9

• ACIS 3DSOLID write support — SAT text builder (R2000–R2007) and SAB binary (R2013+) with primitives: box, wedge, pyramid, cylinder, cone, sphere, torus
• SatDocument builder API — add_plane_surface, add_cone_surface, add_sphere_surface, add_torus_surface, add_straight_curve, add_ellipse_curve
• 208/208 DWG roundtrip integrity — Zero field drift across 26 entity types × 8 versions

0.2.8

• DWG binary read — Full DWG reader for R13 through R2018
• DWG binary write — Full DWG writer for R13 through R2018
• Handle resolution — Automatic owner handle assignment after read

0.2.7

• Optional serde support — Serialize/Deserialize for all document types with features = ["serde"]
• JSON/YAML round-trip — Full document serialization and deserialization

0.2.6

• 41 entity types — Added MultiLeader, Table, MLine, Mesh, Underlay, Ole2Frame, Wipeout, Shape, and more
• Objects — Dictionaries, Groups, Layouts, MLineStyle, MultiLeaderStyle, TableStyle, PlotSettings, Scale, Materials, VisualStyle, GeoData
• CLASSES section — Full read/write support
• Extended data (XData) — Full support for application-specific extended data
• Reactors & extension dictionaries — Read/write for all entity and object types

0.2.0–0.2.5

• ASCII and Binary DXF read/write
• Core entity types (Point, Line, Circle, Arc, Ellipse, Polyline, LwPolyline, Text, MText, Spline, Dimension, Hatch, Solid, Face3D, Insert, Viewport)
• Table system (Layer, LineType, TextStyle, DimStyle, BlockRecord, AppId, View, VPort, UCS)
• Encoding support (~40 code pages)
• Failsafe reading mode
• Unknown entity preservation

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License

MPL-2.0 — see LICENSE.

Acknowledgments

• ACadSharp — the C# library that inspired this project