表白神器
HTML5的canvas画一箭穿心
作为一个专业得程序员，咱们的表白怎能一个送花，几句情话了得，当然是要上代码啦！！！
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Draw Heart</title>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
html {
height: 100%;
margin: 0;
}
body {
height: 100%;
background-color: white;
}
#canvasZone {
width: 100%;
height: 100%;
text-align: center;
background-color: black;
}
#myCanvas {
height: 100%;
display: block;
/*background-color:aqua;*/
}
.text {
width: 220px;
height: 520px;
display: block;
top: 70px;
right: 50px;
color: aqua;
background-color: black;
position: fixed;
}
</style>
</head>
<body>
<div id="text" class="text">
</div>
<div id="canvasZone">
<canvas id="myCanvas"></canvas>
</div>
<audio src="love.mp3" autoplay="autoplay">
Your browser does not support the audio element.
</audio>
</body>
<script type="text/javascript">
var r = 3;
var radian; //弧度
var i;
var radianDecrement; //弧度增量
var time = 5; //每个点之间的时间间隔
var intervalId;
var num = 360; //分割为 360 个点
var startRadian = Math.PI;
var ctx;
var startX = 100;
var startY = 80;
window.onload = function() {
startAnimation();
setTimeout(function() {
startX = 155;
startY = 70;
ctx.moveTo(startX, startY);
drawHeart();
ctx.strokeStyle = "aqua"
}, 2500);
setTimeout(function() {
textLove();
}, 6000);
setTimeout(function() {
ctx.strokeStyle = "red"
addText();
}, 6000)
}
function textLove() {
ctx.lineWidth = 2;
var x = 40;
var y = 100;
ctx.moveTo(x, y);
textLove = setInterval(function(){
ctx.lineTo(x, 110-0.25*x);
x++;
y++;
ctx.stroke();
if(x==220){
clearInterval(textLove)
}
},10);
setTimeout(function(){
ctx.strokeStyle = "aqua"
ctx.lineTo(220, 55);
ctx.lineTo(210, 50)
ctx.moveTo(221, 55);
ctx.lineTo(213, 65);
ctx.stroke();
},1900);
}
function addText() {
var context = "这里可以放一段告白得文字，把你想说得内容写下来，也就是告白得话！";
let arr = new Array();
arr = context.split("");
var str = "";
var index = 0;
addText = setInterval(function() {
str = document.getElementById("text").innerText;
str += arr[index];
index++;
document.getElementById("text").innerText = str;
if (index == arr.length) {
clearInterval(addText)
}
}, 120)
}
function startAnimation() {
ctx = document.getElementById("myCanvas").getContext("2d");
//让画布撑满整个屏幕，-20是滚动条的位置，需留出。如滚动条出现则会挤压画布。
WINDOW_HEIGHT = document.documentElement.clientHeight - 20;
WINDOW_WIDTH = document.documentElement.clientWidth - 20;
ctx.width = WINDOW_WIDTH;
ctx.heigh = WINDOW_HEIGHT;
drawHeart();
}
function drawHeart() {
ctx.strokeStyle = "red";
ctx.lineWidth = 2; //设置线的宽度
radian = startRadian; //弧度设为初始弧度
radianDecrement = Math.PI / num * 2;
ctx.moveTo(getX(radian), getY(radian)); //移动到初始点
i = 0;
intervalId = setInterval("printHeart()", time);
}
function printHeart() {
radian += radianDecrement;
ctx.lineTo(getX(radian), getY(radian)); //在旧点和新点之间连线
i++;
ctx.stroke(); //画线
if (i >= num) {
clearInterval(intervalId);
}
}
function getX(t) { //由弧度得到 X 坐标
return startX + r * (16 * Math.pow(Math.sin(t), 3));
}
function getY(t) { //由弧度得到 Y 坐标
return startY - r * (13 * Math.cos(t) - 5 * Math.cos(2 * t) - 2 * Math.cos(3 * t) - Math.cos(4 * t));
}
</script>
</html>