原生js+canvas实现贪吃蛇效果

时间:2021-05-25

本文实例为大家分享了canvas实现贪吃蛇效果的具体代码,供大家参考,具体内容如下

效果展示:

源码展示:

页面布局展示:worm.html

<!DOCTYPE html><html> <head> <meta charset="utf-8"> <title>贪吃蛇</title> <style type="text/css"> canvas{ border: 1px solid black; } div{ width: 50px; height: 50px; border: 1px solid black; cursor: pointer; text-align: center; line-height: 50px; } </style> <script type="text/javascript" src="Node.js" ></script> <script type="text/javascript" src="Worm.js" ></script> <script src="Stage.js" type="text/javascript" charset="utf-8"></script> <script type="text/javascript"> function load () { //创建一个舞台 调用print方法打印 stage=new Stage(); //获取ctx var mCanvas=document.getElementById("mCanvas"); ctx=mCanvas.getContext('2d'); stage.print(ctx); startPrint(); } function changeDir(dir){ DIR=dir; } var task; var stage; var ctx; function startPrint () { task=window.setInterval(function () { stage.worm.step(); stage.print(ctx); }, SPEED); } function endPrint () { window.clearInterval(task); } </script> </head> <body onload="load()"> <canvas id="mCanvas" width="500" height="500"> </canvas> <table> <tr> <td></td> <td> <div onclick="changeDir(UP)">UP</div> </td> <td></td> </tr> <tr> <td> <div onclick="changeDir(LEFT)">LEFT</div> </td> <td></td> <td> <div onclick="changeDir(RIGHT)">RIGHT</div> </td> </tr> <tr> <td></td> <td> <div onclick="changeDir(DOWN)">DOWN</div> </td> <td></td> </tr> </table> </body></html>

节点类的js :Node.js

function Node (x, y) { this.x=x; this.y=y; this.equals=function (i, j) { return this.x==i && this.y==j; }; }

舞台类js:Stage.js

/** 舞台类 */function Stage () { this.width=50; this.height=50; this.worm=new Worm(); this.print=function (ctx) { for(i=0; i<this.width; i++){ for(j=0; j<this.height; j++){ //如果当前节点是蛇身子的一部分 //那么换一种颜色绘制 if(this.worm.contains(i,j)){ ctx.fillStyle="#ab55ff"; ctx.fillRect(i*10, j*10, 10, 10); }else if(this.worm.food.equals(i, j)){ ctx.fillStyle="#000000"; ctx.fillRect(i*10, j*10, 10, 10); }else{ ctx.fillStyle="#dddddd"; ctx.fillRect(i*10, j*10, 10, 10); } } } //在舞台的左上角绘制分数 ctx.font="30px Arial"; ctx.fillStyle="#880000"; ctx.fillText("score:"+SCORE, 10,40); };}

蛇类js:Worm.js

/** 蛇类 */var UP=0;var DOWN=1;var LEFT=2;var RIGHT=3; var DIR=UP; var SCORE=0;var SPEED=300;//蛇类初始化的形状function Worm () { this.nodes=[]; this.nodes[this.nodes.length]=new Node(20,10); this.nodes[this.nodes.length]=new Node(20,11); this.nodes[this.nodes.length]=new Node(20,12); this.nodes[this.nodes.length]=new Node(20,13); this.nodes[this.nodes.length]=new Node(20,14); this.nodes[this.nodes.length]=new Node(20,15); this.nodes[this.nodes.length]=new Node(21,15); this.nodes[this.nodes.length]=new Node(22,15); this.nodes[this.nodes.length]=new Node(23,15); this.nodes[this.nodes.length]=new Node(24,15); this.nodes[this.nodes.length]=new Node(24,16); this.nodes[this.nodes.length]=new Node(24,17); this.nodes[this.nodes.length]=new Node(24,18); this.nodes[this.nodes.length]=new Node(24,19); this.step=function () { //计算出头结点 把头节点添加到nodes数组中 var oldHead=this.nodes[0]; var newHead; switch (DIR){ case UP: if(oldHead.y-1<0){ newHead=new Node(oldHead.x, 49); }else{ newHead=new Node(oldHead.x, oldHead.y-1); } break; case DOWN: if(oldHead.y+1>49){ newHead=new Node(oldHead.x, 0); }else{ newHead=new Node(oldHead.x, oldHead.y+1); } break; case LEFT: if(oldHead.x-1<0){ newHead=new Node(49, oldHead.y); }else{ newHead=new Node(oldHead.x-1, oldHead.y); } break; case RIGHT: if(oldHead.x+1>49){ newHead=new Node(0, oldHead.y); }else{ newHead=new Node(oldHead.x+1, oldHead.y); } break; } this.nodes.unshift(newHead); if(!this.food.equals(newHead.x, newHead.y)){ //把尾节点删掉 (在没有吃到食物的时候) this.nodes.pop(); }else{ //吃到了食物 重新生成食物 this.food=this.randomFood(); SCORE+=10; SPEED-=50; endPrint(); startPrint(); } }; this.contains=function (i, j) { for(k=0; k<this.nodes.length; k++){ var node=this.nodes[k]; if(node.x==i && node.y==j){ return true; } } return false; }; //声明生成食物的方法 this.randomFood=function () { var x; var y; do{ x=Math.floor(Math.random()*50); y=Math.floor(Math.random()*50); }while(this.contains(x, y)); return new Node(x, y); }; //声明食物 this.food=this.randomFood(); }

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。

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