[Canvas]RPG游戏雏形 （地图加载，英雄出现并移动）

源码请点此下载并用浏览器打开index.html观看

图例：

代码：

<!DOCTYPE html>
<html lang="utf-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<head>
     <title>地图加载 英雄出现 19.3.6 10:20 by:逆火狂飙 horn19782016@163.com</title>

     <style>
     #canvas{
        background:#ffffff;
        cursor:pointer;
        margin-left:10px;
        margin-top:10px;
        -webkit-box-shadow:3px 3px 6px rgba(0,0,0,0.5);
        -moz-box-shadow:3px 3px 6px rgba(0,0,0,0.5);
        box-shadow:3px 3px 6px rgba(0,0,0,0.5);
     }

     #controls{
        margin-top:10px;
        margin-left:15px;
     }
     </style>

    </head>

     <body onload="init()">
        <div id="controls">
            <input id='animateBtn' type='button' value='开始'/>
        </div>

        <canvas id="canvas" width="160px" height="160px" >
            出现文字表示你的浏览器不支持HTML5
        </canvas>
     </body>
</html>
<script type="text/javascript">
<!--
var paused=true;
animateBtn.onclick=function(e){
    paused=! paused;

    if(paused){
        animateBtn.value="开始";    

    }else{
        animateBtn.value="停止";

        window.requestAnimationFrame(animate);
    }
}

var ctx;// 绘图环境
var r;// 表盘半径
var terrain;
var hero;
function init(){
    // init Canvas
    var canvas=document.getElementById('canvas');
    r=160;
    canvas.width =2*r;
    canvas.height=2*r;
    ctx=canvas.getContext('2d');

    terrain=new Terrain();
    hero=new Hero();

    // 响应键盘事件
    canvas.addEventListener('keydown', doKeyDown, true);
    canvas.focus();
    window.addEventListener('keydown', doKeyDown, true);
};

function draw(){
    // Clear Canvas
    ctx.clearRect(0,0,ctx.canvas.width,ctx.canvas.height);
    ctx.fillStyle="#ECF5FF";
    ctx.fillRect(0,0,ctx.canvas.width,ctx.canvas.height);

    terrain.paint(ctx);
    hero.paint(ctx);
}

function animate(){
    if(!paused){
        draw();
        window.requestAnimationFrame(animate); /// 让浏览器自行决定帧速率
    }
}

function doKeyDown(e) {
    var keyID = e.keyCode ? e.keyCode :e.which;
    if(keyID === 38 || keyID === 87)  { // up arrow and W
        hero.move('up');
        e.preventDefault();
    }
    if(keyID === 39 || keyID === 68)  { // right arrow and D
        hero.move('right');
        e.preventDefault();
    }
    if(keyID === 40 || keyID === 83)  { // down arrow and S
        hero.move('down');
        e.preventDefault();
    }
    if(keyID === 37 || keyID === 65)  { // left arrow and A
        hero.move('left');
        e.preventDefault();
    }
}

//---------------------------------------------------地形类定义开始------------------------------------------------------------------->>
Terrain=function(){
    this.files=["road.png","tree.png","home.png",];

    this.maps=new Array(
        [0,0,0,0,0,0,0,0,0,0],
        [0,0,1,1,1,1,1,1,0,0],
        [0,0,0,0,0,0,0,0,0,0],
        [0,0,2,2,2,2,2,2,2,0],
        [0,0,0,0,0,0,2,0,0,0],
        [0,0,0,2,0,0,2,0,0,0],
        [0,0,0,2,0,0,0,0,0,0],
        [0,2,2,2,2,2,2,2,0,0],
        [0,0,0,0,0,0,0,0,0,0],
        [0,1,1,1,1,1,1,1,1,0],
    );
}
Terrain.prototype={
    files:[],
    // Property
    maps:0,

    // method
    paint:function(ctx){
        for(var i=0;i<this.maps.length;i++){
            var arr=this.maps[i];

            for(var j=0;j<arr.length;j++){
                var value=arr[j];

                var img=new Image();
                img.src=this.files[value];

                ctx.drawImage(img,i*32,j*32);
            }
        }
    },

    getValue:function(i,j){
        if(i<0 || i>=this.maps.length){
            return undefined;
        }
        var arr=this.maps[i];
        if(j<0 || j>=arr.length){
            return undefined;
        }
        var value=arr[j];
        return value;
    },
}
//---------------------------------------------------地形类定义结束-------------------------------------------------------------------<<

//---------------------------------------------------英雄类定义开始------------------------------------------------------------------->>
Hero=function(){
    this.files=["arrow_left.png","arrow_right.png","arrow_up.png","arrow_down.png",];

}
Hero.prototype={
    files:[],
    x:160,
    y:160,
    xTo:160,
    yTo:160,
    step:32,
    direction:'up',

    // method
    paint:function(ctx){
        var img=new Image();

        if(this.direction=='up'){
            img.src=this.files[2];
        }
        if(this.direction=='down'){
            img.src=this.files[3];
        }
        if(this.direction=='left'){
            img.src=this.files[0];
        }
        if(this.direction=='right'){
            img.src=this.files[1];
        }

        ctx.drawImage(img,this.x,this.y);
    },

    move:function(direction){
        this.direction=direction;

        if(this.direction=='up'){
            this.yTo-=this.step;
        }
        if(this.direction=='down'){
            this.yTo+=this.step;
        }
        if(this.direction=='left'){
            this.xTo-=this.step;
        }
        if(this.direction=='right'){
            this.xTo+=this.step;
        }

        if(terrain.getValue(this.xTo/this.step,this.yTo/this.step)==0){
            this.x=this.xTo;
            this.y=this.yTo;
        }else{
            this.xTo=this.x;
            this.yTo=this.y;
        }
    }
}
//---------------------------------------------------英雄类定义结束-------------------------------------------------------------------<<
//-->
</script>

2019年3月6日11点07分