原生js+canvas實現貪吃蛇效果
阿新 • • 發佈:2020-08-03
本文例項為大家分享了canvas實現貪吃蛇效果的具體程式碼,供大家參考,具體內容如下
效果展示:
原始碼展示:
頁面佈局展示:worm.html
<!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>貪吃蛇</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 () { //建立一個舞臺 呼叫print方法列印 stage=new Stage(); //獲取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>
節點類的js :Node.js
/* 節點類 */ function Node (x,y) { this.x=x; this.y=y; this.equals=function (i,j) { return this.x==i && this.y==j; }; }
舞臺類js:Stage.js
/** 舞臺類 */ function Stage () { this.width=50; this.height=50; this.worm=new Worm(); /* 在canvas中繪製舞臺的內容 */ this.print=function (ctx) { for(i=0; i<this.width; i++){ for(j=0; j<this.height; j++){ //如果當前節點是蛇身子的一部分 //那麼換一種顏色繪製 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*10,10); }else{ ctx.fillStyle="#dddddd"; ctx.fillRect(i*10,10); } } } //在舞臺的左上角繪製分數 ctx.font="30px Arial"; ctx.fillStyle="#880000"; ctx.fillText("score:"+SCORE,40); }; }
蛇類js:Worm.js
/** 蛇類 */ var UP=0; var DOWN=1; var LEFT=2; var RIGHT=3; var DIR=UP; var SCORE=0; var SPEED=300; //蛇類初始化的形狀 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(24,16); 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); /* 蛇會走一步 */ this.step=function () { //計算出頭結點 把頭節點新增到nodes陣列中 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)){ //把尾節點刪掉 (在沒有吃到食物的時候) 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(); } }; /* 判斷i,j節點是否是當前蛇身子的一部分 */ 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; }; //宣告生成食物的方法 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); }; //宣告食物 this.food=this.randomFood(); }
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。