dxf-dogstar

dxf-dogstar is a DXF parser and SVG exporter derived from the dxf project v5.3.1., with a focus on practical SVG export controls for CAD workflows.

What This Fork Adds

Compared with the upstream dxf package, this fork adds SVG export features that are useful when DXF files need to be rendered more predictably in web or document pipelines:

• Optional scale for fixed pixel output
• Responsive default SVG sizing when scale is omitted
• Layer filtering with a layer-name array
• UTF-8 / Chinese layer-name filtering support in normal Node.js string usage
• Fit-to-content export behavior
• Padding around exported content
• Source lineweight support from DXF data where available

Install

npm install dxf-dogstar

Basic Usage

const fs = require('fs');
const { Helper } = require('dxf-dogstar');

const dxfText = fs.readFileSync('drawing.dxf', 'utf8');
const helper = new Helper(dxfText);

const svg = helper.toSVG();
fs.writeFileSync('drawing.svg', svg, 'utf8');

When scale is not provided, the generated SVG uses:

• width="100%"
• height="100%"

This is helpful when fixed pixel output makes thin horizontal or vertical strokes look too light in some renderers.

SVG Export Options

helper.toSVG(options) accepts these options:

• scale?: number When provided, output SVG width and height are written in pixels. Example: scale: 2 means the exported SVG dimensions are doubled from drawing units.
• layers?: string[] Export only entities whose layer is included in the array.
• fitToContent?: boolean Default: true When true, export is cropped to the rendered content bounds.
• padding?: number | { top:number, right:number, bottom:number, left:number } Padding in drawing units, applied around the exported content.
• useSourceLineweight?: boolean Default: true Uses DXF lineweight or polyline constant width when available.
• defaultStrokeWidth?: number Fallback stroke width when source lineweight is unavailable.

Example: Fixed Pixel Export

const fs = require('fs');
const { Helper } = require('dxf-dogstar');

const dxfText = fs.readFileSync('drawing.dxf', 'utf8');
const helper = new Helper(dxfText);

const svg = helper.toSVG({
  scale: 2,
  fitToContent: true,
  padding: { top: 10, right: 20, bottom: 10, left: 20 },
  useSourceLineweight: true,
});

fs.writeFileSync('drawing-2x.svg', svg, 'utf8');

Example: Export Specific Layers

const fs = require('fs');
const { Helper } = require('dxf-dogstar');

const dxfText = fs.readFileSync('drawing.dxf', 'utf8');
const helper = new Helper(dxfText);

const svg = helper.toSVG({
  layers: ['c-建筑轮廓', 'A-WALL'],
  fitToContent: true,
  padding: 0,
});

fs.writeFileSync('layers.svg', svg, 'utf8');

Example: Responsive Default Sizing

const fs = require('fs');
const { Helper } = require('dxf-dogstar');

const dxfText = fs.readFileSync('drawing.dxf', 'utf8');
const helper = new Helper(dxfText);

const svg = helper.toSVG({
  layers: ['c-建筑轮廓'],
  fitToContent: true,
  padding: 0,
});

fs.writeFileSync('responsive.svg', svg, 'utf8');

This output uses width="100%" height="100%" because scale is omitted.

Notes

• This fork keeps the original project structure so existing Helper, parseString, denormalise, and related imports remain familiar.
• SVG rendering still depends on the entity types supported by the upstream renderer.
• The added lineweight logic is intended to improve practical SVG output, but exact print-style reproduction may still depend on DXF authoring conventions and external CAD print-style rules.

Development Note

The added Dogstar SVG export enhancements in this fork were developed with Codex GPT-5.4 assistance.

Upstream Project Attribution

This package is a derivative work based on the original dxf project:

• Upstream project: dxf
• Original author listed in the packaged source: Ben Nortier
• Upstream license: MIT

License

This fork is distributed under the MIT License.

The original upstream copyright notice and MIT license text are retained in LICENSE.