phaser/src/geom/intersects/TriangleToCircle.js

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

/**
 * @author       Richard Davey <rich@phaser.io>
 * @copyright    2013-2025 Phaser Studio Inc.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var LineToCircle = require('./LineToCircle');
var Contains = require('../triangle/Contains');

/**
 * Checks if a Triangle and a Circle intersect.
 *
 * A Circle intersects a Triangle if its center is located within it or if any of the Triangle's sides intersect the Circle. As such, the Triangle and the Circle are considered "solid" for the intersection.
 *
 * @function Phaser.Geom.Intersects.TriangleToCircle
 * @since 3.0.0
 *
 * @param {Phaser.Geom.Triangle} triangle - The Triangle to check for intersection.
 * @param {Phaser.Geom.Circle} circle - The Circle to check for intersection.
 *
 * @return {boolean} `true` if the Triangle and the `Circle` intersect, otherwise `false`.
 */
var TriangleToCircle = function (triangle, circle)
{
    //  First the cheapest ones:

    if (
        triangle.left > circle.right ||
        triangle.right < circle.left ||
        triangle.top > circle.bottom ||
        triangle.bottom < circle.top)
    {
        return false;
    }

    if (Contains(triangle, circle.x, circle.y))
    {
        return true;
    }

    if (LineToCircle(triangle.getLineA(), circle))
    {
        return true;
    }

    if (LineToCircle(triangle.getLineB(), circle))
    {
        return true;
    }

    if (LineToCircle(triangle.getLineC(), circle))
    {
        return true;
    }

    return false;
};

module.exports = TriangleToCircle;