@allmaps/triangulate/dist/shared.js

Allmaps Triangulation Library

import inside from 'point-in-polygon-hao';
import { distance, stepDistanceAngle, lineAngle, closeRing, closePolygon } from '@allmaps/stdlib';
// Return an array of points containing the first line point,
// and betwen the first and last line point other points every `dist`
function interpolateLine(line, dist) {
    const lineDistance = distance(line);
    // Note: ciel - 1 instead of floor, such that for round numbers we don't include the last step
    const steps = Math.ceil(lineDistance / dist) - 1;
    const angle = lineAngle(line);
    let currentPoint = line[0];
    const result = [currentPoint];
    for (let step = 1; step <= steps; step++) {
        currentPoint = stepDistanceAngle(currentPoint, dist, angle);
        result.push(currentPoint);
    }
    // Note: the last nextpoint, which is also line[1], is not pushed
    return result;
}
// Return an array of points containing the ring points,
// and between every pair of ring points other points every `dist`
export function interpolateRing(ring, dist) {
    ring = closeRing(ring);
    let result = [];
    for (let i = 0; i < ring.length - 1; i++) {
        result = result.concat(interpolateLine([ring[i], ring[i + 1]], dist));
    }
    return result;
}
export function interpolatePolygon(polygon, dist) {
    return polygon.map((ring) => interpolateRing(ring, dist));
}
export function getGridPointsInBbox(bbox, gridSize) {
    const grid = [];
    for (let x = bbox[0] + gridSize, i = 0; x <= bbox[2]; i++, x += gridSize) {
        for (let y = bbox[1] + gridSize, j = 0; y <= bbox[3]; j++, y += gridSize) {
            grid.push([x, y]);
        }
    }
    return grid;
}
// Returns true if point is inside of polygon with holes
export function pointInPolygon(point, polygon) {
    try {
        return inside(point, closePolygon(polygon)) === true;
    }
    catch (error) {
        console.error('Error determining if point is inside polygon:', error);
        return false;
    }
}