两物体间的角度

原文地址：http://www.phaser.io/examples/v2/arcade-physics/angle-between。

效果

源代码

window.onload = function () {
    var game = new Phaser.Game(600, 400, Phaser.AUTO, 'phaser_container', 
                            { preload: preload, create: create, update: update, render: render }); 

    function preload() {

        game.load.image('arrow', 'images/phaser/longarrow.png');
        game.load.image('ball', 'images/phaser/pangball.png');

    }

    var arrow;
    var target;

    function create() {

        game.physics.startSystem(Phaser.Physics.ARCADE);

        game.stage.backgroundColor = '#0072bc';

        arrow = game.add.sprite(200, 250, 'arrow');
        arrow.anchor.setTo(0.1, 0.5);

        target = game.add.sprite(400, 300, 'ball');
        target.anchor.setTo(0.5, 0.5);
        target.inputEnabled = true;
        target.input.enableDrag(true);

    }

    function update() {

        arrow.rotation = game.physics.arcade.angleBetween(arrow, target);

    }

    function render() {

        game.debug.text("拖动球", 32, 32);
        game.debug.spriteInfo(arrow, 32, 100);

    }
}

解释

angleBetween(source, target, world) → {number}

获取两个显示对象之间的角度（单位为弧度）。可选参数world返回的是基于Game Object的world属性的结果，若没有这个参数，则返回常规的x和y值。

发布时间：2016/8/17 21:58:13  阅读次数：4115