1.Canvas 实现圆形进度条并显示数字百分比
1.首先创建html代码
2.创建canvas环境
var canvas = document.getElementById('canvas'), //获取canvas元素
context = canvas.getContext('2d'), //获取画图环境,指明为2d
centerX = canvas.width/2, //Canvas中心点x轴坐标
centerY = canvas.height/2, //Canvas中心点y轴坐标
rad = Math.PI*2/100, //将360度分成100份,那么每一份就是rad度
speed = 0.1; //加载的快慢就靠它了
3.绘制5像素宽的运动外圈
//绘制5像素宽的运动外圈
function blueCircle(n){
context.save();
context.strokeStyle = "#fff"; //设置描边样式
context.lineWidth = 5; //设置线宽
context.beginPath(); //路径开始
context.arc(centerX, centerY, 100 , -Math.PI/2, -Math.PI/2 +n*rad, false); //用于绘制圆弧context.arc(x坐标,y坐标,半径,起始角度,终止角度,顺时针/逆时针)
context.stroke(); //绘制
context.closePath(); //路径结束
context.restore();
}
4.绘制红色运动圈
function whiteCircle(){
context.save();
context.beginPath();
context.lineWidth = 2; //设置线宽
context.strokeStyle = "red";
context.arc(centerX, centerY, 100 , 0, Math.PI*2, false);
context.stroke();
context.closePath();
context.restore();
}
5.百分比文字绘制
function text(n){
context.save(); //save和restore可以保证样式属性只运用于该段canvas元素
context.strokeStyle = "#fff"; //设置描边样式
context.font = "40px Arial"; //设置字体大小和字体
//绘制字体,并且指定位置
context.strokeText(n.toFixed(0)+"%", centerX-25, centerY+10);
context.stroke(); //执行绘制
context.restore();
}
6.让它运动起来
(function drawFrame(){
window.requestAnimationFrame(drawFrame);
context.clearRect(0, 0, canvas.width, canvas.height);
whiteCircle();
text(speed);
blueCircle(speed);
if(speed > 100) speed = 0;
speed += 0.1;
}());
完整代码
HTML5 Canvas 圆形进度条并显示数字百分比
2.H5实现树叶飘落
html代码:
HTML5树叶飘落动画
这是基于webkit的落叶动画
css代码:
body{
background-color: #4E4226;
}
#container {
position: relative;
height: 700px;
width: 500px;
margin: 10px auto;
overflow: hidden;
border: 4px solid #5C090A;
background: #4E4226 url('images/backgroundLeaves.jpg') no-repeat top left;
}
#leafContainer {
position: absolute;
width: 100%;
height: 100%;
}
#message{
position: absolute;
top: 160px;
width: 100%;
height: 300px;
background:transparent url('images/textBackground.png') repeat-x center;
color: #5C090A;
font-size: 220%;
font-family: 'Georgia';
text-align: center;
padding: 20px 10px;
-webkit-box-sizing: border-box;
-webkit-background-size: 100% 100%;
z-index: 1;
}
em {
font-weight: bold;
font-style: normal;
}
#leafContainer > div {
position: absolute;
width: 100px;
height: 100px;
-webkit-animation-iteration-count: infinite;
-webkit-animation-direction: normal;
-webkit-animation-timing-function: linear;
}
#leafContainer > div > img {
position: absolute;
width: 100px;
height: 100px;
-webkit-animation-iteration-count: infinite;
-webkit-animation-direction: alternate;
-webkit-animation-timing-function: ease-in-out;
-webkit-transform-origin: 50% -100%;
}
@-webkit-keyframes fade{
0% { opacity: 1; }
95% { opacity: 1; }
100% { opacity: 0; }
}
@-webkit-keyframes drop{
0% { -webkit-transform: translate(0px, -50px); }
100% { -webkit-transform: translate(0px, 650px); }
}
@-webkit-keyframes clockwiseSpin{
0% { -webkit-transform: rotate(-50deg); }
100% { -webkit-transform: rotate(50deg); }
}
@-webkit-keyframes counterclockwiseSpinAndFlip {
0% { -webkit-transform: scale(-1, 1) rotate(50deg); }
100% { -webkit-transform: scale(-1, 1) rotate(-50deg); }
}
js代码:
const NUMBER_OF_LEAVES = 30;
function init(){
var container = document.getElementById('leafContainer');
for (var i = 0; i < NUMBER_OF_LEAVES; i++) {
container.appendChild(createALeaf());
}
}
function randomInteger(low, high){
return low + Math.floor(Math.random() * (high - low));
}
function randomFloat(low, high){
return low + Math.random() * (high - low);
}
function pixelValue(value){
return value + 'px';
}
function durationValue(value){
return value + 's';
}
function createALeaf(){
var leafDiv = document.createElement('div');
leafDiv.style.top = "-100px";
leafDiv.style.left = pixelValue(randomInteger(0, 500));
leafDiv.style.webkitAnimationName = 'fade, drop';
var fadeAndDropDuration = durationValue(randomFloat(5, 11));
leafDiv.style.webkitAnimationDuration = fadeAndDropDuration + ', ' + fadeAndDropDuration;
var leafDelay = durationValue(randomFloat(0, 5));
leafDiv.style.webkitAnimationDelay = leafDelay + ', ' + leafDelay;
var image = document.createElement('img');
image.src = 'images/realLeaf' + randomInteger(1, 5) + '.png';
var spinAnimationName = (Math.random() < 0.5) ? 'clockwiseSpin' : 'counterclockwiseSpinAndFlip';
image.style.webkitAnimationName = spinAnimationName;
var spinDuration = durationValue(randomFloat(4, 8));
image.style.webkitAnimationDuration = spinDuration;
leafDiv.appendChild(image);
return leafDiv;
}
window.addEventListener('load', init, false);
转载地址:http://www.html5tricks.com/css3-fall-leaves.html
3.canvas处理连续帧图片
html5 canvas处理连续帧图片,下面的代码基于IE8以上
Canvas Demo
后续逐渐添加