shaku/src/collision/shapes/circle.js

A simple and effective JavaScript game development framework that knows its place!

/**
 * Implement collision circle.
 * 
 * |-- copyright and license --|
 * @module     Shaku
 * @file       shaku\src\collision\shapes\circle.js
 * @author     Ronen Ness (ronenness@gmail.com | http://ronenness.com)
 * @copyright  (c) 2021 Ronen Ness
 * @license    MIT
 * |-- end copyright and license --|
 * 
 */

 'use strict';
const CollisionShape = require("./shape");
const gfx = require('./../../gfx');
const Circle = require("../../utils/circle");
const Rectangle = require("../../utils/rectangle");


/**
 * Collision circle class.
 */
class CircleShape extends CollisionShape
{
    /**
     * Create the collision shape.
     * @param {Circle} circle the circle shape.
     */
    constructor(circle)
    {
        super();
        this.setShape(circle);
    }

    /**
     * @inheritdoc
     */
    get shapeId()
    {
        return "circle";
    }

    /**
     * Set this collision shape from circle.
     * @param {Circle} circle Circle shape.
     */
    setShape(circle)
    {
        this._circle = circle;
        this._position = circle.center;
        this._boundingBox = new Rectangle(circle.center.x - circle.radius, circle.center.y - circle.radius, circle.radius * 2, circle.radius * 2);
        this._shapeChanged();
    }
 
    /**
     * @inheritdoc
     */
    _getRadius()
    {
        return this._circle.radius;
    }
    
    /**
     * @inheritdoc
     */
    getCenter()
    {
        return this._position.clone();
    }

    /**
     * @inheritdoc
     */
    _getBoundingBox()
    {
        return this._boundingBox;
    }

    /**
     * @inheritdoc
     */
    debugDraw(opacity, shapesBatch)
    {
        if (opacity === undefined) { opacity = 1; }
        let color = this._getDebugColor();
        color.a *= opacity;
        shapesBatch = this._getDebugDrawBatch(shapesBatch);
        let needToBegin = !shapesBatch.isDrawing;
        if (needToBegin) { shapesBatch.begin(); }
        shapesBatch.drawCircle(this._circle, color, 14);
        if (needToBegin) { shapesBatch.end(); }
    }
}

// export collision shape class
module.exports = CircleShape;