@davepagurek/flo-mat/src/find-mat/get-for-2-prongs-on-loop.ts

Medial / Scale Axis Transform (MAT/SAT) Library.

import { splitByCurvatureAndLength, controlPointLinesLength } from 'flo-bezier3';
import { Loop } from 'flo-boolean';
import { PointOnShape } from '../point-on-shape/point-on-shape.js';
import { createPos } from '../point-on-shape/create-pos.js';


/**
 * @internal
 * Get useful points on the shape - these incude points of maximum curvature and 
 * points at the bezier-bezier interfaces.  
 * @param loop
 * @param additionalPointCount 
 */
function getFor2ProngsOnLoop(
        minBezLength: number,
        maxCurviness: number,
        maxLength: number) {

    return function(loop: Loop) {
        const for2Prongs: PointOnShape[] = [];

        for (let i=0; i<loop.curves.length; i++) {
            const curve = loop.curves[i];

            if (controlPointLinesLength(curve.ps) < minBezLength) {
                continue;
            }
            
            let ts = splitByCurvatureAndLength(curve.ps, maxCurviness, maxLength);
            // add at least one in the middle
            if (ts.length === 2) { ts = [0, 0.5, 1]; }

            const byCurvatureAndLength = 
                ts.slice(1,ts.length-1).map(t => createPos(curve, t, true));

            for2Prongs.push(...byCurvatureAndLength);
        }

        return for2Prongs;
    }
}


export { getFor2ProngsOnLoop }