Html Canvas JavaScript自制贪吃蛇小游戏

tech2023-01-24  57

单文件html,直接复制可用。

可调节速度和随机大小食物。

<html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <meta http-equiv="X-UA-Compatible" content="ie=edge"> <title>Snake</title> <style> .text{ width: 100%; line-height: 30px; height: 30px; font-size: 16pt; text-align: center; } canvas{ display: block; margin: 30px auto; border: solid; border-width: 1px; border-color:rgb(51, 51, 51); box-shadow: 0 0 12px 2px rgba(51, 51, 51, 0.8); } .slider-contain{ text-align: center; position: relative; } .slider-bar{ display: inline-block; height: 8px; width: 300px; background-color: rgb(218, 218, 218); border: solid; border-color: rgb(218, 218, 218); border-width: 1px; box-shadow: 0 0 8px 2px rgba(97, 97, 97, 0.8); } .slider-block{ position: absolute; height: 23px; width: 10px; background-color: rgb(8, 85, 8); margin-top: -7px; cursor: pointer; } </style> </head> <body> <div class="text" id="score">0</div> <canvas id="canvas"></canvas> <div class="slider-contain"> <abbr title="拖动调节速度"> <div class="slider-bar"> <div class="slider-block"></div> </div> </abbr> </div> <br><br> <div class="text"> 上下左右控制方向 </div> <div class="text"> F5重新开始|空格暂停/继续 </div> </body> <script> const direction={ UP:0, RIGHT:1, DOWN:2, LEFT:3 } var snake={ color:'#04573D', headColor:'#211E1E', size:10, length:3, direction:direction.RIGHT, speed:100,// 200ms/move 1 time 200-50 body:[ {x:25,y:145}, {x:15,y:145}, {x:5,y:145} ],//每一节身体的位置 tail:[]//记录所有的尾巴,以便吃到食物后增长,按食物大小增长长度 } var food={ color:'#8F401F', size:10, position:{x:200,y:200},//食物出现的位置 } var map={ color:'#868686', } var Game=function(){ this.score=0;//计分 this.isDealControl=true;//是否处理了方向控制 this.pause=false;//游戏暂停 this.direction=direction;//方向枚举 this.snake=snake;//蛇 this.food=food;//食物 this.map=map; //地图 this.canvas=document.getElementById('canvas'); this.canvas.width = 300; this.canvas.height = 300; this.cxt=this.canvas.getContext("2d"); let speed=localStorage.getItem("snake_speed"); if(speed) this.snake.speed=parseInt(speed); else localStorage.setItem('snake_speed',this.snake.speed); this.init(); this.draw_map(); this.create_food(); window.onkeyup=this.control.bind(this); } Game.prototype.draw_map=function(){ this.cxt.fillStyle=this.map.color; this.cxt.fillRect(0,0,this.canvas.width,this.canvas.height); } Game.prototype.reset_map=function(){ this.cxt.clearRect(0,0,this.canvas.width,this.canvas.height); this.draw_map(); this.draw_snake(); this.draw_food(); } Game.prototype.draw_snake=function(){ for(var i in this.snake.body){ if(i==0)//头部 this.cxt.fillStyle=this.snake.headColor; else this.cxt.fillStyle=this.snake.color; this.cxt.fillRect(this.snake.body[i].x-this.snake.size/2,this.snake.body[i].y-this.snake.size/2,this.snake.size,this.snake.size); } } Game.prototype.create_food=function(){ this.food.size=10+Math.round(Math.random()*20); this.food.position.x=Math.round(Math.random()*this.canvas.width); this.food.position.y=Math.round(Math.random()*this.canvas.height); if(this.food.position.x<this.food.size/2)this.food.position.x=this.food.size/2; if(this.food.position.y<this.food.size/2)this.food.position.y=this.food.size/2; if(this.food.position.x>this.canvas.width-this.food.size/2)this.food.position.x=this.canvas.width-this.food.size/2 if(this.food.position.y>this.canvas.height-this.food.size/2)this.food.position.y=this.canvas.height-this.food.size/2 } Game.prototype.draw_food=function(){ this.cxt.fillStyle=this.food.color; this.cxt.fillRect(this.food.position.x-this.food.size/2,this.food.position.y-this.food.size/2,this.food.size,this.food.size); } Game.prototype.move=function(){ const json=JSON.stringify(this.snake.body); const oldbody=JSON.parse(json); this.snake.tail.push(oldbody[oldbody.length-1]); //续上尾巴个数 let tailCount=1; //每截身体移动:头部移动,之后的每一节=前一节 for(var i=0;i<this.snake.length;i++){ if(i==0) { switch(this.snake.direction){ case direction.UP:this.snake.body[i].y-=this.snake.size;break; case direction.RIGHT:this.snake.body[i].x+=this.snake.size;break; case direction.DOWN:this.snake.body[i].y+=this.snake.size;break; case direction.LEFT:this.snake.body[i].x-=this.snake.size;break; } } else{ if(i<this.snake.body.length){ this.snake.body[i]=oldbody[i-1] }else{ this.snake.body[i]=this.snake.tail[this.snake.tail.length-tailCount] tailCount++; } } } this.isDealControl=true; //碰撞检测 //碰撞墙壁 if(this.snake.body[0].x-this.snake.size/2<0||this.snake.body[0].x+this.snake.size/2>this.canvas.width||this.snake.body[0].y-this.snake.size/2<0||this.snake.body[0].y+this.snake.size/2>this.canvas.height){ return false; } //碰撞自己 xy均有重叠 for(var i=1;i<this.snake.body.length;i++) { if( Math.abs(this.snake.body[0].x - this.snake.body[i].x) < this.snake.size/2 + this.snake.size/2 && Math.abs(this.snake.body[0].y - this.snake.body[i].y) < this.snake.size/2 + this.snake.size/2 ){ return false; } } //碰撞食物 if( Math.abs(this.snake.body[0].x - this.food.position.x) < this.snake.size/2 + this.food.size/2 && Math.abs(this.snake.body[0].y - this.food.position.y) < this.snake.size/2 + this.food.size/2 ){ this.create_food(); this.snake.length+=Math.ceil(this.food.size/this.snake.size); this.score+=this.food.size; } return true; } Game.prototype.control=function(e){ if(!this.isDealControl) return; switch(e.keyCode){ case 37:if(this.snake.direction!==direction.RIGHT){this.snake.direction=direction.LEFT;this.isDealControl=false;}break; case 38:if(this.snake.direction!==direction.DOWN){this.snake.direction=direction.UP;this.isDealControl=false;}break; case 39:if(this.snake.direction!==direction.LEFT){this.snake.direction=direction.RIGHT;this.isDealControl=false;}break; case 40:if(this.snake.direction!==direction.UP){this.snake.direction=direction.DOWN;this.isDealControl=false;}break; case 32: this.pause=!this.pause; if(!this.pause)this.go(); break; } } Game.prototype.init=function(){ let that=this; let slider_bar=document.getElementsByClassName('slider-bar')[0]; let slider_block=document.getElementsByClassName('slider-block')[0]; let moveX; slider_block.style.left = (slider_bar.offsetLeft+(200-this.snake.speed)*2)+'px'; slider_block.onmousedown=function(event){ var event = event || window.event; var diffX = event.clientX - slider_block.offsetLeft; var diffY = event.clientY - slider_block.offsetTop; if(typeof slider_block.setCapture !== 'undefined'){ slider_block.setCapture(); } document.onmousemove = function(event){ var event = event || window.event; moveX = event.clientX - diffX; if(moveX<slider_bar.offsetLeft) moveX=slider_bar.offsetLeft; if(moveX>slider_bar.offsetLeft+slider_bar.offsetWidth) moveX=slider_bar.offsetLeft+slider_bar.offsetWidth // var moveY = event.clientY - diffY; if(moveX < 0){ moveX = 0 }else if(moveX > window.innerWidth - slider_block.offsetWidth){ moveX = window.innerWidth - slider_block.offsetWidth } // if(moveY < 0){ // moveY = 0 // }else if(moveY > window.innerHeight - slider_block.offsetHeight){ // moveY = window.innerHeight - slider_block.offsetHeight // } slider_block.style.left = moveX + 'px'; // slider_block.style.top = moveY + 'px' } document.onmouseup = function(event){ this.onmousemove = null; this.onmouseup = null; //value:0-300 speed:200-50 let value=moveX-slider_bar.offsetLeft; let speed=200-value*0.5; localStorage.setItem('snake_speed',speed); that.snake.speed=speed; //低版本ie bug if(typeof slider_block.releaseCapture!='undefined'){ slider_block.releaseCapture(); } } } } Game.prototype.go=function(){ if(!this.move()) { alert('你没了'); return } this.reset_map(); //计分 document.getElementById('score').innerHTML=this.score; if(this.pause)return; setTimeout(() => { this.go(); }, this.snake.speed); } var game=new Game(); game.go(); </script> </html>

 

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