HTML5 椭圆（蛋）运动的小球



	 

	椭圆与椭圆运动：

	 

	 

	 

	             var canvas=document.getElementById("ballBroad");

	 

	            var context=canvas.getContext("2d");

	            //角度

	            var angle=0;

	            //角度步长

	            var speedAngle=0.1;

	           

	            //刷新频率

	            var frames=1000/60;

	            //球对象

	            var Ball=function(radius,color,x,y)

	            {

	                this.radius=radius;

	                this.color=color;

	                this.x=x;

	                this.y=y;

	            }

	            //中心点

	            var centerX=canvas.width/2;

	            var centerY=canvas.height/2;

	            //存放小球走过的点

	            var points=[];

	           

	           

	            //创建一个球

	            var newBall=new Ball(20,"#ff000",0,centerY);

	            

	            //在画板中间绘制球

	            //DrawBall(newBall);

	            //存放

	            //points.push({x:newBall.x,y:newBall.y});

	           

	           

	            //让球平稳的动起来

	            var drawAsync = eval(Jscex.compile("async", function () {

	                        while(true)

	                        {

	                            newBall.y=centerY+Math.sin(angle)*(centerY/2+20);

	                            newBall.x=centerX+Math.cos(angle)*centerX;

	                            angle+=speedAngle;

	                            DrawBall(newBall);

	                            //存放小球的点

	                            points.push({x:newBall.x,y:newBall.y});

	                           

	                            //绘制线条

	                            DrawBallLine();

	                            //画蛋疼

	                            DrawText("蛋疼",centerX-50,centerY);

	                            //每秒60次

	                            $await(Jscex.Async.sleep(frames));

	                           

	                        }   

	                       

	                                                                   

	            }));

	           drawAsync().start();

	          

	           function DrawBall(ball)

	           {

	               context.clearRect(0, 0, canvas.width, canvas.height);

	               //在画板中间绘制球

补充：web前端 , HTML 5 ,