Canvas放置反弹效果随机图形 

  1    var raf;
  2    var arror = [];
  3    var running = false;
  4    //绘制圆形
  5    function createBall() {
  6        return {
  7            x: 0,
  8            y: 0,
  9            vx: 10-Math.random()*10,
 10            vy: 10-Math.random()*10,
 11            radius: 25,
 12            color:"red",
 13            draw: function() {
 14                ctx.beginPath();
 15                ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, true);
 16                ctx.closePath();
 17                ctx.fillStyle = this.color;
 18                ctx.fill();
 19            }
 20        }
 21    }
 22    //绘制正方形
 23    function createSquare() {
 24        return {
 25            x: 0,
 26            y: 0,
 27            vx: 10-Math.random()*10,
 28            vy: 10-Math.random()*10,
 29            color:"red",
 30            draw: function() {
 31                ctx.beginPath();
 32                ctx.fillStyle = this.color;
 33                ctx.fillRect(this.x, this.y,30, 30);
 34                ctx.closePath();
 35            }
 36        }
 37    }
 38    //绘制五角星
 39    function createStar() {
 40        return {
 41            x: 0,
 42            y: 0,
 43            vx: 10-Math.random()*10,
 44            vy: 10-Math.random()*10,
 45            color:"red",
 46            draw: function() {
 47                ctx.font = "24px serif";
 48                ctx.textBaseline = "hanging";
 49                ctx.fillStyle=this.color;
 50                ctx.fillText("五角星",this.x, this.y);
 51 
 52            }
 53        }
 54    }
 55    //绘制三角形
 56    function createTriangle() {
 57        return {
 58            x: 0,
 59            y: 0,
 60            vx: 10-Math.random()*10,
 61            vy: 10-Math.random()*10,
 62            color:"red",
 63            draw: function() {
 64                ctx.beginPath();
 65                ctx.moveTo(this.x,this.y);
 66                ctx.lineTo(this.x+25,this.y+25);
 67                ctx.lineTo(this.x+25,this.y-25);
 68                ctx.fillStyle=this.color;
 69                ctx.fill();
 70            }
 71        }
 72    }
 73    //清除
 74    function clear() {
 75        ctx.fillStyle = 'rgba(255,255,255,0.3)';
 76        ctx.fillRect(0,0,canvas.width,canvas.height);
 77    }
　　　　//判断图形坐标是否超出画布范围
 78    function draw() {
 79        clear();
 80        arror.forEach(function(ball, i){
 81            ball.draw();
 82            ball.x += ball.vx;
 83            ball.y += ball.vy;
 84            if (ball.y + ball.vy > canvas.height || ball.y + ball.vy < 0) {
 85                ball.vy = -ball.vy;
 86            }
 87            if (ball.x + ball.vx > canvas.width || ball.x + ball.vx < 0) {
 88                ball.vx = -ball.vx;
 89            }
 90        });
 91 
 92        raf = window.requestAnimationFrame(draw);
 93    }
 94    canvas.addEventListener('click',function(e){
 95        if (!running) {
 96            raf = window.requestAnimationFrame(draw);
 97            running = true;
 98        }
 99        var colorarr=["#000000","#7F7F7F","#880015","#ED1C24","#FF7F27","#FFF200","#22B14C","#00A2E8","#3F48CC","#A349A4","#B97A57","#FFAEC9","#B5E61D"];
100        var Graphics = ["Round","Square","Star","Triangle"];
101        var typexz=Graphics[Math.floor(Math.random()*4)];
102        var ball;
103        switch(typexz){
104            case "Round":
105                ball = createBall();
106                break;
107            case "Square":
108                ball = createSquare();
109                break;
110            case "Star":
111                ball = createStar();
112                break;
113            case "Triangle":
114                ball = createTriangle();
115                break;
116        }
117        ball.x = e.clientX;
118        ball.y = e.clientY;
119        ball.color = colorarr[Math.floor(Math.random() * 10 + 3)];
120        arror.push(ball);
121    });
122    draw();
123   document.addEventListener('keydown',function (e) {
124       if(e.keyCode==32){
125           event.preventDefault();
126           window.cancelAnimationFrame(raf);
127           running = false;
128       }
129   })

 

posted @ 2017-08-16 17:15  紫菜、  阅读(369)  评论(0)    收藏  举报