point-is-in-polygon/lib/entities/point/point.js

The `point-is-in-polygon` package is a lightweight package that was developed to check if the coordinates of a point are in the coordinates of a polygon.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Point = void 0;
var line_string_1 = require("../line-string/line-string");
var Point = /** @class */ (function () {
    function Point(_a) {
        var x = _a.x, y = _a.y;
        this.x = x;
        this.y = y;
        Object.freeze(this);
    }
    Point.prototype.calc = function (x1, y1, x2, y2, x3, y3, x4, y4) {
        var denominator = (x1 - x2) * (y3 - y4) - (y1 - y2) * (x3 - x4);
        var t = ((x1 - x3) * (y3 - y4) - (y1 - y3) * (x3 - x4)) / denominator;
        var u = ((x1 - x3) * (y1 - y2) - (y1 - y3) * (x1 - x2)) / denominator;
        return {
            t: t,
            u: u,
        };
    };
    Point.prototype.haveIntersectionPoint = function (x1, y1, x2, y2, x3, y3, x4, y4) {
        var _a = this.calc(x1, y1, x2, y2, x3, y3, x4, y4), t = _a.t, u = _a.u;
        if (t >= 0 && t <= 1 && u >= 0 && u <= 1)
            return true;
        return false;
    };
    Point.prototype.getIntersectionPoint = function (x1, y1, x2, y2, x3, y3, x4, y4) {
        var t = this.calc(x1, y1, x2, y2, x3, y3, x4, y4).t;
        var intersectionPointX = x1 + t * (x2 - x1);
        var intersectionPointY = y1 + t * (y2 - y1);
        return {
            x: intersectionPointX,
            y: intersectionPointY,
        };
    };
    Point.prototype.createIntersectionLines = function (polygon) {
        var maxX = polygon.coordinates.sort(function (a, b) { return b.x - a.x; })[0].x;
        var minX = polygon.coordinates.sort(function (a, b) { return a.x - b.x; })[0].x;
        var maxY = polygon.coordinates.sort(function (a, b) { return b.y - a.y; })[0].y;
        var minY = polygon.coordinates.sort(function (a, b) { return a.y - b.y; })[0].y;
        return [
            new line_string_1.LineString([
                {
                    x: this.x,
                    y: this.y,
                },
                {
                    x: maxX,
                    y: this.y,
                },
            ]),
            new line_string_1.LineString([
                {
                    x: this.x,
                    y: this.y,
                },
                {
                    x: minX,
                    y: this.y,
                },
            ]),
            new line_string_1.LineString([
                {
                    x: this.x,
                    y: this.y,
                },
                {
                    x: this.x,
                    y: maxY,
                },
            ]),
            new line_string_1.LineString([
                {
                    x: this.x,
                    y: this.y,
                },
                {
                    x: this.x,
                    y: minY,
                },
            ]),
        ];
    };
    Point.prototype.isInPolygon = function (polygon) {
        var _this = this;
        var intersectionLines = this.createIntersectionLines(polygon);
        var intersectionPoints = [];
        var _loop_1 = function (i) {
            intersectionLines.forEach(function (intersectionLine) {
                var intersections = [];
                var x1 = intersectionLine.points[0].x;
                var y1 = intersectionLine.points[0].y;
                var x2 = intersectionLine.points[1].x;
                var y2 = intersectionLine.points[1].y;
                var x3 = polygon.coordinates[i - 1].x;
                var y3 = polygon.coordinates[i - 1].y;
                var x4 = polygon.coordinates[i].x;
                var y4 = polygon.coordinates[i].y;
                var haveIntersectionPoint = _this.getIntersectionPoint(x1, y1, x2, y2, x3, y3, x4, y4);
                if (haveIntersectionPoint) {
                    var intersectionPoint = _this.getIntersectionPoint(x1, y1, x2, y2, x3, y3, x4, y4);
                    intersections.push(intersectionPoint);
                }
                var uniqueIntersections = [];
                intersections.forEach(function (_a) {
                    var x = _a.x, y = _a.y;
                    var isUnique = !uniqueIntersections.find(function (coordinate) {
                        return coordinate.x === x && coordinate.y === y;
                    });
                    if (isUnique)
                        uniqueIntersections.push({ x: x, y: y });
                });
                intersectionPoints.push(uniqueIntersections);
            });
        };
        for (var i = 1; i < polygon.coordinates.length; i++) {
            _loop_1(i);
        }
        return !intersectionPoints
            .map(function (coordinates) {
            return coordinates.length % 2 === 0;
        })
            .some(function (result) { return result === true; });
    };
    return Point;
}());
exports.Point = Point;