本文实例讲述了JavaScript+html5 canvas绘制的小人效果。分享给大家供大家参考，具体如下：

运行效果截图如下：

index.html代码如下：

canvas中的缩放

#canvas {

background:black; margin-top:100px; margin-left:200px;

}

cache = {};

var offsetX = 50,

offsetY = 20;

cache.context = dyl.createContext('canvas');

dyl.rect(dyl.createColor(), 60 + offsetX, 0 + offsetY, 185, 100);

dyl.rect(dyl.createColor(), 100 + offsetX, 100 + offsetY, 100, 50);

dyl.rect(dyl.createColor(), 20 + offsetX, 150 + offsetY, 260, 200);

dyl.rect(dyl.createColor(), 80 + offsetX, 350 + offsetY, 30, 110);

dyl.rect(dyl.createColor(), 190 + offsetX, 350 + offsetY, 30, 110);

dyl.circle(dyl.createColor(), 115 + offsetX, 55, 20);

dyl.circle(dyl.createColor(), 190 + offsetX, 55, 20);

canvas.js代码如下：

(function() {

var dyl = {cache: {}};

dyl.setContext = function(context) {

dyl.cache._context = context;

return context;

}

dyl.getDom = function(id) {

return document.getElementById(id);

}

dyl._getContext = function() {

return dyl.cache._context;

}

dyl.save = function() {

var context = dyl._getContext();

context ? context.save() : void(0);

}

dyl.restore = function() {

var context = dyl._getContext();

context ? context.restore() : void(0);

}

dyl.createContext = function(canvasID) {

var canvas = this.getDom(canvasID);

if(!canvas) {

return null;

}

return dyl.setContext(canvas.getContext("2d"));

}

dyl.createColor = function() {

var color = "rgb(";

color += Math.round(Math.random()*255);

color += ",";

color += Math.round(Math.random()*255);

color += ",";

color += Math.round(Math.random()*255);

color += ")";

return color;

};

dyl.addImg = function(img, x, y) {

var context = dyl._getContext();

if(!img || !context) {

return;

}

if(typeof img === "string") {

var oImg = new Image();

oImg.src = img;

oImg.onload = function() {

context.drawImage(oImg, x, y);

}

return;

}

context.drawImage(img, x, y);

};

dyl.rect = function(color, x, y, width, height) {

var context = dyl._getContext();

if(!context) {

return;

}

context.fillStyle = color;

context.fillRect(x, y, width, height);

};

dyl.circle = function(color, x, y, r) {

var context = dyl._getContext();

context.save();

context.fillStyle = color;

context.beginPath();

context.arc(x, y, r, 0, 2*Math.PI);

context.fill();

context.stroke();

};

dyl.scale = function(x, y) {

var context = dyl._getContext();

if(!context) {

return;

}

x = x ? x : 1;

y = y ? y : 1;

context.scale(x, y);

};

if(!window.dyl) {

window.dyl = dyl;

}

})();

希望本文所述对大家JavaScript程序设计有所帮助。