phaser/src/geom/intersects/GetTriangleToLine.js

A fast, free and fun HTML5 Game Framework for Desktop and Mobile web browsers from the team at Phaser Studio Inc.

/**
 * @author       Florian Vazelle
 * @author       Geoffrey Glaive
 * @copyright    2013-2025 Phaser Studio Inc.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var Point = require('../point/Point');
var TriangleToLine = require('./TriangleToLine');
var LineToLine = require('./LineToLine');

/**
 * Checks if a Triangle and a Line intersect, and returns the intersection points as a Point object array.
 *
 * The Line intersects the Triangle if it starts inside of it, ends inside of it, or crosses any of the Triangle's sides. Thus, the Triangle is considered "solid".
 *
 * @function Phaser.Geom.Intersects.GetTriangleToLine
 * @since 3.0.0
 *
 * @param {Phaser.Geom.Triangle} triangle - The Triangle to check with.
 * @param {Phaser.Geom.Line} line - The Line to check with.
 * @param {array} [out] - An optional array in which to store the points of intersection.
 *
 * @return {array} An array with the points of intersection if objects intersect, otherwise an empty array.
 */
var GetTriangleToLine = function (triangle, line, out)
{
    if (out === undefined) { out = []; }

    if (TriangleToLine(triangle, line))
    {
        var lineA = triangle.getLineA();
        var lineB = triangle.getLineB();
        var lineC = triangle.getLineC();

        var output = [ new Point(), new Point(), new Point() ];

        var result = [
            LineToLine(lineA, line, output[0]),
            LineToLine(lineB, line, output[1]),
            LineToLine(lineC, line, output[2])
        ];

        for (var i = 0; i < 3; i++)
        {
            if (result[i]) { out.push(output[i]); }
        }
    }

    return out;
};

module.exports = GetTriangleToLine;