index.ts

import * as makerjs from "makerjs";

export interface options {
    bezierAccuracy?: number;
    joints?: number;
    inside?: boolean;
    outside?: boolean;
    tagName?: 'path' | 'polygon' | 'polyline';
}

export default function outline (svgData: string, distance: number, opts?: options): string {

    const defaultOptions: options = {
        bezierAccuracy: 0.25,
        joints: 0,
        outside: true,
        tagName: 'path'
    };

    var o = makerjs.extendObject(defaultOptions, opts) as options;

    let closed = true;
    let input: makerjs.IModel;

    switch (o.tagName) {
        case 'polyline':
            closed = false;
        //fall through

        case 'polygon':
            //use points. 
            //Need to mirror them on y axis because they are expected to be in MakerJs coordinate space
            input = makerjs.model.mirror(new makerjs.models.ConnectTheDots(closed, svgData), false, true);
            break;

        default:
            input = makerjs.importer.fromSVGPathData(svgData, { bezierAccuracy: o.bezierAccuracy });
            break;
    }

    var result: makerjs.IModel;

    if (o.inside && o.outside) {
        result = makerjs.model.expandPaths(input, distance, o.joints);
    } else {
        result = makerjs.model.outline(input, distance, o.joints, o.inside);
    }

    makerjs.model.simplify(result);

    return makerjs.exporter.toSVGPathData(result, false, [0, 0]) as string;
}

module.exports = outline;