大鱼吃小鱼游戏-ane.js

// 定义海葵对象类
var aneObj = function()
{
    this.x = [];    //海葵x位置
    this.len = [];  //海葵长度
}
// 定义海葵原型对象数量
aneObj.prototype.num = 50;
// 海葵初始化，随机产生海葵x位置和长度
aneObj.prototype.init = function()
{
    for (var i = 0; i < this.num; i++)
    {
        this.x[i] = i *16 + Math.random() *20; //[0,1)
        this.len[i] = 200 + Math.random() *50;

        //console.log("a");

    }
}
// 画海葵
aneObj.prototype.draw = function()
{
    ctx2.save();

    ctx2.globalAlpha = 0.6;//海葵的透明度
    ctx2.lineCap = "round";//海葵线头形状
    ctx2.strokeStyle = "#3b154a";//海葵的颜色
    ctx2.lineWidth = 20;    //海葵的粗细 
    for(var i =  0; i<this.num; i++)
    {
        //beginPath, moveTo, lineTo, lineWidth, lineCap, strokeStyle, stroke
        ctx2.beginPath();
        ctx2.moveTo(this.x[i], canHeight);
        ctx2.lineTo(this.x[i], canHeight - this.len[i]);        
        ctx2.stroke();
    }

    ctx2.restore();
}