@math.gl/polygon/dist/polygon.js

Polygon/polyline processing utilities

// math.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
/* eslint-disable no-undef, no-console */
import { isArray } from '@math.gl/core';
import { getPolygonSignedArea, forEachSegmentInPolygon, modifyPolygonWindingDirection, getPolygonSignedAreaPoints, forEachSegmentInPolygonPoints, modifyPolygonWindingDirectionPoints } from "./polygon-utils.js";
export class Polygon {
    constructor(points, options = {}) {
        this.points = points;
        this.isFlatArray = !isArray(points[0]);
        this.options = {
            start: options.start || 0,
            end: options.end || points.length,
            size: options.size || 2,
            isClosed: options.isClosed
        };
        Object.freeze(this);
    }
    /**
     * Returns signed area of the polygon.
     * @returns Signed area of the polygon.
     */
    getSignedArea() {
        if (this.isFlatArray)
            return getPolygonSignedArea(this.points, this.options);
        return getPolygonSignedAreaPoints(this.points, this.options);
    }
    /**
     * Returns absolute area of the polygon.
     * @returns Absolute area of the polygon.
     */
    getArea() {
        return Math.abs(this.getSignedArea());
    }
    /**
     * Returns winding direction of the polygon.
     * @returns Winding direction of the polygon. 1 is for clockwise, -1 for counterclockwise winding direction.
     */
    getWindingDirection() {
        return Math.sign(this.getSignedArea());
    }
    /**
     * Calls the visitor callback for each segment in the polygon.
     * @param visitor A callback to call for each segment.
     */
    forEachSegment(visitor) {
        if (this.isFlatArray) {
            forEachSegmentInPolygon(this.points, 
            // eslint-disable-next-line max-params
            (x1, y1, x2, y2, i1, i2) => {
                // TODO @igorDykhta original visitor uses arrays for each point, but with flat arrays performance degrades if we allocate points for each segment
                visitor([x1, y1], [x2, y2], i1, i2);
            }, this.options);
        }
        else {
            forEachSegmentInPolygonPoints(this.points, visitor, this.options);
        }
    }
    /**
     * Checks winding direction of the polygon and reverses the polygon in case of opposite winding direction.
     * @param direction Requested winding direction. 1 is for clockwise, -1 for counterclockwise winding direction.
     * @return Returns true if the winding direction was changed.
     */
    modifyWindingDirection(direction) {
        if (this.isFlatArray) {
            return modifyPolygonWindingDirection(this.points, direction, this.options);
        }
        return modifyPolygonWindingDirectionPoints(this.points, direction, this.options);
    }
}
//# sourceMappingURL=polygon.js.map