dxf-writer

To use the DXF writer in your project, install the dxf-writer package using npm.

npm install dxf-writer

To create a DXF file, instantiate the Drawing class, add your desired entities using the drawing methods, and call generateAutocadExtras() to ensure compatibility with AutoCAD products. Finally, call toDxfString() to get the serialized DXF content.

Important: You must call generateAutocadExtras() before exporting to ensure required metadata (like ACADVER, VPORT, and STYLE tables) is included.

const Drawing = require('js-dxf');

const drawing = new Drawing();

// 1. Add entities
drawing.drawLine(0, 0, 10, 10);

// 2. CRITICAL: Generate AutoCAD compatibility metadata
drawing.generateAutocadExtras();

// 3. Export to string
const dxfString = drawing.toDxfString();

In a Node.js environment, you can create a new Drawing instance, define layers, draw various entities, and export the result as a DXF string. The API supports both standard method calls and a fluent interface for chaining commands like addLayer and setActiveLayer.

const Drawing = require('dxf-writer');
const fs = require('fs');

let d = new Drawing();

d.setUnits('Decimeters');
d.drawText(10, 0, 10, 0, 'Hello World'); // draw text in the default layer named "0"
d.addLayer('l_green', Drawing.ACI.GREEN, 'CONTINUOUS');
d.setActiveLayer('l_green');
d.drawText(20, -70, 10, 0, 'go green!');

//or fluent
d.addLayer('l_yellow', Drawing.ACI.YELLOW, 'DOTTED')
 .setActiveLayer('l_yellow')
 .drawCircle(50, -30, 25);

fs.writeFileSync(__filename + '.dxf', d.toDxfString());

The library provides three built-in line types: CONTINUOUS, DASHED, and DOTTED. You can also define custom line types using the addLineType method.

let d = new Drawing();
d.addLineType('DASHDOT', '_ . _ ', [0.5, -0.5, 0.0, -0.5]);

Supported Colors

• red
• green
• cyan
• blue
• magenta
• white

Supported Units

• Unitless
• Inches
• Feet
• Miles
• Millimeters
• Centimeters
• Meters
• Kilometers
• Microinches
• Mils
• Yards
• Angstroms
• Nanometers
• Microns
• Decimeters
• Decameters
• Hectometers
• Gigameters
• Astronomical units
• Light years
• Parsecs

The library supports drawing the following entities:

• arc
• circle
• ellipse
• line
• point
• polygon
• polyline
• polyline 3D
• spline
• text
• 3DFace

Entities are drawn on the activeLayer. You can create new layers using addLayer(name, colorNumber, lineTypeName) and switch between them using setActiveLayer(name).

To set the color of the current layer using AutoCAD Color Index (ACI), use setTrueColor(trueColor). You can use the Drawing.ACI constant for standard colors.

Available ACI Colors:

• Drawing.ACI.LAYER (0)
• Drawing.ACI.RED (1)
• Drawing.ACI.YELLOW (2)
• Drawing.ACI.GREEN (3)
• Drawing.ACI.CYAN (4)
• Drawing.ACI.BLUE (5)
• Drawing.ACI.MAGENTA (6)
• Drawing.ACI.WHITE (7)

const drawing = new Drawing();

// Add a custom layer
drawing.addLayer("Construction", Drawing.ACI.RED, "CONTINUOUS");

// Switch to it
drawing.setActiveLayer("Construction");

// Draw on that layer
drawing.drawLine(0, 0, 5, 5);

The js-dxf library provides a Drawing class as its primary entry point. You can instantiate this class to create a new DXF drawing and then use its methods to add various geometric entities (like lines, circles, arcs, etc.) to the file. Once the drawing is populated, you can export it as a DXF-formatted string.

const Drawing = require('js-dxf');

const drawing = new Drawing();
// Add entities to the drawing here...
const dxfString = drawing.toDXFString();

The Spline class allows you to create spline entities for DXF files. You can define the spline using control points, a specific degree (quadratic or cubic), an optional knot vector, and optional weights for rational splines. If no knot vector is provided, a uniform knot vector is automatically generated.

Constraints:

• The number of controlPoints must be at least degree + 1.
• If weights are provided, there must be exactly one weight for each control point.
• If knots are provided, the length must be exactly controlPoints.length + degree + 1.

const Spline = require('dxf-writer').Spline; // Assuming standard export pattern

const controlPoints = [[0, 0], [1, 1], [2, 0]];
const degree = 2; // Quadratic spline

const spline = new Spline(controlPoints, degree);

Set the drawing units using setUnits(unit). The unit string must correspond to one of the keys in Drawing.UNITS.

Supported Units:

• Unitless (0)
• Inches (1)
• Feet (2)
• Miles (3)
• Millimeters (4)
• Centimeters (5)
• Meters (6)
• Kilometers (7)
• Microinches (8)
• Mils (9)
• Yards (10)
• Angstroms (11)
• Nanometers (12)
• Microns (13)
• Decimeters (14)
• Decameters (15)
• Hectometers (16)
• Gigameters (17)
• Astronomical units (18)
• Light years (19)
• Parsecs (20)

const drawing = new Drawing();
drawing.setUnits("Millimeters");

The Spline constructor accepts the following parameters: