[Canvas]双方战机展示

时间：2023-09-20 15:38:02

源码点此下载，用chrome浏览器打开index.html观看。

图例：

[Canvas]双方战机展示

代码：

<!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1.04 19.3.13 16:54 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;

function init(){
    bg=new Background();

    var canvas=document.getElementById('canvas');
    canvas.width=bg.width*6;
    canvas.height=bg.height*4;
    ctx=canvas.getContext('2d');

    lastTime=+new Date;
};

function update(){

}

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);

    var plane1=new Image();
    plane1.src="1.png";
    ctx.drawImage(plane1,ctx.canvas.width/2-280,canvas.height-100);

    var plane2=new Image();
    plane2.src="2.png";
    ctx.drawImage(plane2,ctx.canvas.width/2-200,canvas.height-100);

    var plane3=new Image();
    plane3.src="3.png";
    ctx.drawImage(plane3,ctx.canvas.width/2-120,canvas.height-100);

    var plane4=new Image();
    plane4.src="4.png";
    ctx.drawImage(plane4,ctx.canvas.width/2-40,canvas.height-100);

    var plane5=new Image();
    plane5.src="5.png";
    ctx.drawImage(plane5,ctx.canvas.width/2+80,canvas.height-100);

    var plane6=new Image();
    plane6.src="6.png";
    ctx.drawImage(plane6,ctx.canvas.width/2+200,canvas.height-100);

    var e1=new Image();
    e1.src="e1.png";
    ctx.drawImage(e1,ctx.canvas.width/2-280,100);

    var e2=new Image();
    e2.src="e2.png";
    ctx.drawImage(e2,ctx.canvas.width/2-200,100);

    var e3=new Image();
    e3.src="e3.png";
    ctx.drawImage(e3,ctx.canvas.width/2-120,110);

    var e4=new Image();
    e4.src="e4.png";
    ctx.drawImage(e4,ctx.canvas.width/2-20,80);

    var e5=new Image();
    e5.src="e5.png";
    ctx.drawImage(e5,ctx.canvas.width/2+80,130);

    var e6=new Image();
    e6.src="e6.png";
    ctx.drawImage(e6,ctx.canvas.width/2+160,100);

    var e7=new Image();
    e7.src="e7.png";
    ctx.drawImage(e7,ctx.canvas.width/2-280,200);

    var e8=new Image();
    e8.src="e8.png";
    ctx.drawImage(e8,ctx.canvas.width/2-120,200);

    /*
    ctx.font="bold 16px 宋体";
    ctx.fillStyle='white';
    ctx.fillText("FPS:"+Math.floor(fps),20,40);
    */
}

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={
    width: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<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

//-->
</script>

2019年3月13日18点32分

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