maplibre-gl/src/symbol/check_max_angle.test.ts

BSD licensed community fork of mapbox-gl, a WebGL interactive maps library

import Point from '@mapbox/point-geometry';
import checkMaxAngle from './check_max_angle';
import Anchor from './anchor';

describe('checkMaxAngle', () => {
    test('line with no sharp angles', () => {
        const line = [new Point(0, 0), new Point(20, -1), new Point(40, 1), new Point(60, 0)];
        const anchor = new Anchor(30, 0, 0, 1);
        expect(checkMaxAngle(line, anchor, 25, 20, Math.PI / 8)).toBeTruthy();
        expect(checkMaxAngle(line, anchor, 25, 20, 0)).toBeFalsy();
    });

    test('one sharp corner', () => {
        const line = [new Point(0, 0), new Point(0, 10), new Point(10, 10)];
        const anchor = new Anchor(0, 10, 0, 1);
        expect(checkMaxAngle(line, anchor, 10, 5, Math.PI / 2)).toBeTruthy();
        expect(checkMaxAngle(line, anchor, 10, 5, Math.PI / 2 - 0.01)).toBeFalsy();
    });

    test('many small corners close together', () => {
        const line = [
            new Point(0, 0), new Point(10, 0), new Point(11, 0.1),
            new Point(12, 0.3), new Point(13, 0.6), new Point(14, 1), new Point(13.9, 10)];
        const anchor = new Anchor(12, 0.3, 0, 3);
        expect(checkMaxAngle(line, anchor, 10, 5, Math.PI / 2)).toBeFalsy();
        expect(checkMaxAngle(line, anchor, 10, 2, Math.PI / 2)).toBeTruthy();
    });

    test('label appears on the first line segment', () => {
        const line = [new Point(0, 0), new Point(100, 0)];
        const anchor = new Anchor(50, 0, 0, 0);
        expect(checkMaxAngle(line, anchor, 30, 5, Math.PI / 2)).toBeTruthy();
    });

    test('not enough space before the end of the line', () => {
        const line = [new Point(0, 0), new Point(10, 0), new Point(20, 0), new Point(30, 0)];
        const anchor = new Anchor(5, 0, 0, 0);
        expect(checkMaxAngle(line, anchor, 11, 5, Math.PI)).toBeFalsy();
        expect(checkMaxAngle(line, anchor, 10, 5, Math.PI)).toBeTruthy();
    });

    test('not enough space after the beginning of the line', () => {
        const line = [new Point(0, 0), new Point(10, 0), new Point(20, 0), new Point(30, 0)];
        const anchor = new Anchor(25, 0, 0, 2);
        expect(checkMaxAngle(line, anchor, 11, 5, Math.PI)).toBeFalsy();
        expect(checkMaxAngle(line, anchor, 10, 5, Math.PI)).toBeTruthy();
    });
});