[Canvas]空战游戏进阶 增加发射子弹 敌机中弹爆炸功能

点此下载源码

图例:

源码:

<!DOCTYPE html>
<html lang="utf-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<head>
     <title>飞越河谷的战机1.06 19.3.14 9:45 by:逆火狂飙 horn19782016@163.com</title>
     
     <style>
     *{
        margin:1px;
        padding:1px;
     }
     #canvas{
        background:#ffffff;
     }
     
     #controls{
        float:left;
     }
     </style>
     
    </head>

     <body onload="init()">
        <table border="0px">
            <tr>
                <td width="50px"valign="top">
                    <div id="controls">
                        <input id='animateBtn' type='button' value='运动'/>
                    </div>
                </td>
                <td width="100%" align="center">
                    <canvas id="canvas" width="1200px" height="562px" >
                    出现文字表示你的浏览器不支持HTML5
                    </canvas>
                </td>
            </tr>
        </table>
     
        <div>
            
            

        </div>
        
     

     </body>
</html>
<script type="text/javascript">
<!--
var paused=true;
animateBtn.onclick=function(e){
    paused=! paused;
    
    if(paused){
        animateBtn.value="运动";
        
    }else{    
        animateBtn.value="暂停";
        window.requestAnimationFrame(animate); 
    }
}

var ctx;        // 绘图环境
var bg;            // 背景
var lastTime=0;
var fps=0;
var myPlane;
var myShells;
var enemyPlaneMng;

function init(){
    // 创建背景对象
    bg=new Background();
    
    // 初始化CTX
    var canvas=document.getElementById('canvas');
    canvas.width=bg.width*6;
    canvas.height=bg.height*4;
    ctx=canvas.getContext('2d');
    
    lastTime=+new Date;
    
    // 创建本机对象
    myPlane=new MyPlane(ctx.canvas.width/2,canvas.height-100);
    
    myShells=new Array();
    
    enemyPlaneMng=new EnemyPlaneMng();
    
    // 响应键盘按下事件
    canvas.addEventListener('keydown', doKeyDown, true);
    window.addEventListener('keydown', doKeyDown, true);
    
    // 响应键盘弹起事件
    canvas.addEventListener('keyup', doKeyUp, true);
    window.addEventListener('keyup', doKeyUp, true);
    
    canvas.focus();  
};

//------------------------------------
// 响应键盘按下事件
//------------------------------------
function doKeyDown(e) {
    var keyID = e.keyCode ? e.keyCode :e.which;
    if(keyID === 38 || keyID === 87)  { // up arrow and W
        myPlane.toUp=true;
        e.preventDefault();
    }
    if(keyID === 40 || keyID === 83)  { // down arrow and S
        myPlane.toDown=true;
        e.preventDefault();
    }
    
    if(keyID === 39 || keyID === 68)  { // right arrow and D
        myPlane.toRight=true;
        e.preventDefault();
    }
    
    if(keyID === 37 || keyID === 65)  { // left arrow and A
        myPlane.toLeft=true;
        e.preventDefault();
    }
    
    if(keyID === 32 )  { // SpaceBar
        myPlane.isShoot=true;
        e.preventDefault();
    }
}

//------------------------------------
// 响应键盘弹起事件
//------------------------------------
function doKeyUp(e) {
    var keyID = e.keyCode ? e.keyCode :e.which;
    if(keyID === 38 || keyID === 87)  { // up arrow and W
        myPlane.toUp=false;
        e.preventDefault();
    }
    if(keyID === 40 || keyID === 83)  { // down arrow and S
        myPlane.toDown=false;
        e.preventDefault();
    }
    
    if(keyID === 39 || keyID === 68)  { // right arrow and D
        myPlane.toRight=false;
        e.preventDefault();
    }
    
    if(keyID === 37 || keyID === 65)  { // left arrow and A
        myPlane.toLeft=false;
        e.preventDefault();
    }
    
    if(keyID === 32 )  { // SpaceBar
        myPlane.isShoot=false;
        e.preventDefault();
    }
}

// 更新各对象状态
function update(){
    myPlane.move();
    
    for(var i=0;i<myShells.length;i++){
        var myShell=myShells[i];
        
        if(myShell.destroyed==false){
            if(enemyPlaneMng.isShooted(myShell.x,myShell.y)==true){
                myShell.destroyed=true;
            }
        }
        
        myShell.move();
    }
    
    enemyPlaneMng.move();
}

// 在CTX画出各个对象
function draw(){
    ctx.clearRect(0,0,ctx.canvas.width,ctx.canvas.height);
    
    fps=calculateFps(new Date);    
    bg.setOffset(fps);
    
    var bgImg=bg.getImage();
    ctx.drawImage(bgImg,0,bg.height-bg.Offset,bg.width,bg.Offset,0,0,ctx.canvas.width,4*bg.Offset);
    ctx.drawImage(bgImg,0,0,bg.width,bg.height-bg.Offset,0,4*bg.Offset,canvas.width,canvas.height-4*bg.Offset);
    
    
    myPlane.paint(ctx);
    
    for(var i=0;i<myShells.length;i++){
        var myShell=myShells[i];
        myShell.paint(ctx);
    }
    
    enemyPlaneMng.paint(ctx);
}

function calculateFps(now){
    var retval=1000/(now-lastTime);
    lastTime=now;
    // console.log("fps",retval)
    return retval;
}

function animate(){
    if(!paused){
        update();
        draw();
    }
    
    window.requestAnimationFrame(animate);
}

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>点类定义开始>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Point=function(x,y){
    this.x=x;
    this.y=y;
}
Point.prototype={
    x:0,            // 横坐标
    y:0,            // 纵坐标
}
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<点类定义结束<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<


//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>背景类定义开始>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Background=function(){
    this.width=104;
    this.height=156;
    this.files=['bgBlue.jpg','bgRiver.jpg','bgSky.jpg','bgVolcano.jpg'];
    this.Offset=0;
    this.velocity=40;
}
Background.prototype={
    104,                // 背景图片原始宽度
    height:156,                // 背景图片原始高度
    files:[],                // 图片数组
    Offset:0,                // 偏移值
    velocity:40,            // 背景移动速度
    loopValue:0,            // 循环累加值,用来确定时哪一张图片
    
    getImage:function(){
        this.loopValue++;
        if(this.loopValue>=3999){
            this.loopValue=0;
        }
        
        var index=Math.floor(this.loopValue/1000);
        var img=new Image();
        img.src=this.files[index];
        return img;
    },
    
    setOffset:function(fps){
        this.Offset=this.Offset<this.height?this.Offset+this.velocity/fps:0;
    },
}
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<背景类定义结束<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>我方战机类定义开始>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
MyPlane=function(x,y){
    Point.apply(this,arguments);
    this.types=[
                {56,height:41,file:'m1.png'},
                {56,height:41,file:'m2.png'},
                {80,height:54,file:'m3.png'},
                {109,height:83,file:'m4.png'},
                {109,height:81,file:'m5.png'},
                {109,height:91,file:'m6.png'},
               ];
}
MyPlane.prototype={
    files:[],           // 存储图片的数组
    step:4,                // 每次移动多远
    toLeft:false,        // 是否向左移动
    toRight:false,        // 是否向右移动
    toUp:false,            // 是否向上移动
    toDown:false,        // 是否向下移动
    level:3,            // 等级
    isShoot:false,        // 是否开炮
    
    paint:function(ctx){                
        var img=new Image();
        var index=this.level;
        
        img.src=this.types[index].file;
        
        ctx.drawImage(img,this.x-this.types[index].width/2,this.y-this.types[index].height/2);
        
        var img2=new Image();
        img2.src="shoot.png";
        ctx.drawImage(img2,this.x-5.5,this.y-5.5);
    },
    
    move:function(){
        // 加入边界判断 2019年3月13日19点16分
        var type=this.types[this.level].file;
        
        if(this.x<0){
            this.x=0;
            this.toLeft=false;
        }
        if(this.x>ctx.canvas.width){
            this.x=ctx.canvas.width;
            this.toRight=false;
        }
        
        if(this.y<0){
            this.y=0;
            this.toUp=false;
        }
        
        if(this.y>ctx.canvas.height){
            this.y=ctx.canvas.height;
            this.toDown=false;
        }
        
        // 运动
        if(this.toLeft==true){
            this.x-=this.step;
        }
        if(this.toRight==true){
            this.x+=this.step;
        }
        if(this.toUp==true){
            this.y-=this.step;
        }
        if(this.toDown==true){
            this.y+=this.step;
        }    

        // 开炮
        if(this.isShoot==true){
            var myShell=new MyShell(this.x,this.y);
            myShells.push(myShell);
        }
    },
}
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<我方战机类定义结束<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>我方炮弹类定义开始>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
MyShell=function(x,y){
    Point.apply(this,arguments);
    //this.files=['shell0.png','shell1.png','shell2.png','shell3.png','shell4.png','shell5.png','shell6.png','shell7.png',];
    
    this.types=[
        {11,height:11,file:'shell0.png'},
        {11,height:11,file:'shell1.png'},
        {11,height:11,file:'shell2.png'},
        {11,height:11,file:'shell3.png'},
        {11,height:11,file:'shell4.png'},
        {11,height:11,file:'shell5.png'},
        {11,height:11,file:'shell6.png'},
        {18,height:18,file:'shell7.png'},
    ];
    
}
MyShell.prototype={
    types:[],        // 炮弹型号
    destroyed:false,// 是否被敌机撞毁
    visible:true,    // 是否在CTX显示范围内
    level:3,        // 等级,用以决定炮弹型号
    
    paint:function(ctx){  
        if(this.visible==false){
            return;
        }
    
        if(this.destroyed==false){
            //var img2=new Image();
            //img2.src=this.files[0];
            //ctx.drawImage(img2,this.x-5.5,this.y-5.5);
            
            // 没被击毁显示飞机型号
            var img=new Image();
            var index=this.level;            
            img.src=this.types[index].file;            
            ctx.drawImage(img,this.x-this.types[index].width/2,this.y-this.types[index].height/2);
        }
    },
    
    move:function(){
        // 设置越界不可见        
        if(this.x<0){
            this.visible=false;
        }
        if(this.x>ctx.canvas.width){
            this.visible=false;
        }
        
        if(this.y<0){
            this.visible=false;
        }
        
        if(this.y>ctx.canvas.height){
            this.visible=false;
        }
        
        if(this.visible==true){
            this.y-=18;
        }
    },
}
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<我方炮弹类定义结束<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>敌方飞机类定义开始>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
EnemyPlane=function(x,y,level){
    Point.apply(this,arguments);
    this.level=level;

    this.types=[
        {117,height:64,file:'e0.png'},
        {117,height:64,file:'e1.png'},
        {100,height:77,file:'e2.png'},
        {117,height:85,file:'e3.png'},
        {117,height:93,file:'e4.png'},
        {117,height:93,file:'e5.png'},
        {117,height:96,file:'e6.png'},
        {117,height:99,file:'e7.png'},
    ];
    
    this.explosions=[
        {105,height:100,file:'explosion0.png'},
        {105,height:100,file:'explosion1.png'},
        {105,height:100,file:'explosion2.png'},
        {105,height:100,file:'explosion3.png'},
        {105,height:100,file:'explosion4.png'},
        {105,height:100,file:'explosion5.png'},
    ];
}
EnemyPlane.prototype={
    types:[],            // 飞机型号数组
    destroyed:false,    // 是否被击毁
    level:7,            // 等级,用此取飞机型号
    visible:true,        // 是否在ctx显示范围内
    explosions:[],        // 爆炸图片
    destroyTime:0,        // 被摧毁时间
    
    paint:function(ctx){  
        // 不可见则不显示
        if(this.visible==false){
            return;
        }
    
        if(this.destroyed==false){
            // 没被击毁显示飞机型号
            var img=new Image();
            var index=this.level;
            
            img.src=this.types[index].file;
            
            ctx.drawImage(img,this.x-this.types[index].width/2,this.y-this.types[index].height/2);
            
            var img2=new Image();
            img2.src="shoot.png";
            ctx.drawImage(img2,this.x-5.5,this.y-5.5);
        }else{            
            var index=Math.floor(this.destroyTime);
            
            if(index<this.explosions.length){
                this.destroyTime+=0.05;
                var img=new Image();            
                img.src=this.explosions[index].file;            
                ctx.drawImage(img,this.x-this.explosions[index].width/2,this.y-this.explosions[index].height/2);
            }
        }
    },
    
    move:function(){
        // 设置越界不可见        
        if(this.x<0){
            this.visible=false;
        }
        if(this.x>ctx.canvas.width){
            this.visible=false;
        }
        
        if(this.y<0){
            this.visible=false;
        }
        
        if(this.y>ctx.canvas.height){
            this.visible=false;
        }
        
        if(this.visible){
            this.y+=1;
        }
    },
}
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<敌方飞机类定义结束<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

//>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>敌方飞机管理类定义开始>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
EnemyPlaneMng=function(x,y){
    Point.apply(this,arguments);
    
    this.planes=new Array();
    this.planes.push(new EnemyPlane(ctx.canvas.width/2,20,0));
    this.planes.push(new EnemyPlane(ctx.canvas.width/2-80,20,1));
    this.planes.push(new EnemyPlane(ctx.canvas.width/2+80,20,3));
}
EnemyPlaneMng.prototype={
    planes:[],
    
    paint:function(ctx){                
        for(var i=0;i<this.planes.length;i++){
            var plane=this.planes[i];
            plane.paint(ctx);
        }
    },
    
    move:function(){
        for(var i=0;i<this.planes.length;i++){
            var plane=this.planes[i];
            plane.move();
        }
    },
    
    isShooted:function(x,y){
        for(var i=0;i<this.planes.length;i++){
            var plane=this.planes[i];
            
            if(plane.visible==true && plane.destroyed==false){
                var xDiff=x-plane.x;
                var yDiff=y-plane.y;
                var distance=Math.sqrt(Math.pow(xDiff,2)+Math.pow(yDiff,2));
                console.log(distance);
                if(distance<5){
                    plane.destroyed=true;
                    return true;
                }
            }            
        }
        
        return false;
    },
}
//<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<敌方飞机管理类定义结束<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
//-->
</script>

2019年3月14日19点54分

原文地址:https://www.cnblogs.com/heyang78/p/10533038.html