PracticalVision/node_modules/roughjs/bin/fillers/hachure-filler.js

import { lineLength, lineIntersection, doIntersect, isPointInPolygon } from '../geometry';
import { polygonHachureLines } from './scan-line-hachure';
export class HachureFiller {
    constructor(helper) {
        this.helper = helper;
    }
    fillPolygon(points, o) {
        return this._fillPolygon(points, o);
    }
    _fillPolygon(points, o, connectEnds = false) {
        let lines = polygonHachureLines(points, o);
        if (connectEnds) {
            const connectingLines = this.connectingLines(points, lines);
            lines = lines.concat(connectingLines);
        }
        const ops = this.renderLines(lines, o);
        return { type: 'fillSketch', ops };
    }
    renderLines(lines, o) {
        const ops = [];
        for (const line of lines) {
            ops.push(...this.helper.doubleLineOps(line[0][0], line[0][1], line[1][0], line[1][1], o));
        }
        return ops;
    }
    connectingLines(polygon, lines) {
        const result = [];
        if (lines.length > 1) {
            for (let i = 1; i < lines.length; i++) {
                const prev = lines[i - 1];
                if (lineLength(prev) < 3) {
                    continue;
                }
                const current = lines[i];
                const segment = [current[0], prev[1]];
                if (lineLength(segment) > 3) {
                    const segSplits = this.splitOnIntersections(polygon, segment);
                    result.push(...segSplits);
                }
            }
        }
        return result;
    }
    midPointInPolygon(polygon, segment) {
        return isPointInPolygon(polygon, (segment[0][0] + segment[1][0]) / 2, (segment[0][1] + segment[1][1]) / 2);
    }
    splitOnIntersections(polygon, segment) {
        const error = Math.max(5, lineLength(segment) * 0.1);
        const intersections = [];
        for (let i = 0; i < polygon.length; i++) {
            const p1 = polygon[i];
            const p2 = polygon[(i + 1) % polygon.length];
            if (doIntersect(p1, p2, ...segment)) {
                const ip = lineIntersection(p1, p2, segment[0], segment[1]);
                if (ip) {
                    const d0 = lineLength([ip, segment[0]]);
                    const d1 = lineLength([ip, segment[1]]);
                    if (d0 > error && d1 > error) {
                        intersections.push({
                            point: ip,
                            distance: d0
                        });
                    }
                }
            }
        }
        if (intersections.length > 1) {
            const ips = intersections.sort((a, b) => a.distance - b.distance).map((d) => d.point);
            if (!isPointInPolygon(polygon, ...segment[0])) {
                ips.shift();
            }
            if (!isPointInPolygon(polygon, ...segment[1])) {
                ips.pop();
            }
            if (ips.length <= 1) {
                if (this.midPointInPolygon(polygon, segment)) {
                    return [segment];
                }
                else {
                    return [];
                }
            }
            const spoints = [segment[0], ...ips, segment[1]];
            const slines = [];
            for (let i = 0; i < (spoints.length - 1); i += 2) {
                const subSegment = [spoints[i], spoints[i + 1]];
                if (this.midPointInPolygon(polygon, subSegment)) {
                    slines.push(subSegment);
                }
            }
            return slines;
        }
        else if (this.midPointInPolygon(polygon, segment)) {
            return [segment];
        }
        else {
            return [];
        }
    }
}