【告白气球——HTML实现】
效果
背景、歌词等可以根据自己的需要加以修改，也可以设置添加背景音乐~
代码
doctype html>
<html>
<head>
<meta charset="utf-8">
<title>情人节快乐！——追光者♂title>
<style>
canvas {
position: absolute;
top: 0;
left: 0;
}style>
head>
<body>
<canvas id=c>canvas>
<script>
var w = c.width = window.innerWidth,
h = c.height = window.innerHeight,
ctx = c.getContext( '2d' ),
opts = {
phrases: [ "塞纳河畔左岸的咖啡", "我手一杯品尝你的美", "留下唇印的嘴", "花店玫瑰名字写错谁", "告白气球风吹到对街", "微笑在天上飞", "你说你有点难追", "想让我知难而退", "礼物不需挑太贵", "只要香榭的落叶" ],
balloons: 10,
baseVelY: -1,
addedVelY: -1,
baseVelX: -.25,
addedVelX: .5,
baseSize: 20,
addedSize: 10,
baseSizeAdder: 2,
addedSizeAdder: 2,
baseIncrementer: .01,
addedIncrementer: .03,
baseHue: -10,
addedHue: 30,
font: '15px Verdana'
},
cycle = 0,
balloons = [];
ctx.font = opts.font;
function Balloon(){
this.reset();
}
Balloon.prototype.reset = function(){
this.size = opts.baseSize + opts.addedSize * Math.random();
this.sizeAdder = opts.baseSizeAdder + opts.addedSizeAdder * Math.random();
this.incrementer = opts.baseIncrementer + opts.addedIncrementer * Math.random();
this.tick = 0;
this.x = Math.random() * w;
this.y = h + this.size;
this.vx = opts.baseVelX + opts.addedVelX * Math.random();
this.vy = opts.baseVelY + opts.addedVelY * Math.random();
this.color = 'hsla(hue,70%,60%,.8)'.replace( 'hue', opts.baseHue + opts.addedHue * Math.random() );
this.phrase = opts.phrases[ ++cycle % opts.phrases.length ].split( '\n' );
this.lengths = [];
for( var i = 0; i < this.phrase.length; ++i )
this.lengths.push( -ctx.measureText( this.phrase[ i ] ).width / 2 );
}
Balloon.prototype.step = function(){
this.tick += this.incrementer;
this.x += this.vx;
this.y += this.vy;
var size = this.size + this.sizeAdder * Math.sin( this.tick );
ctx.lineWidth = size / 40;
ctx.strokeStyle = '#eee';
ctx.beginPath();
ctx.moveTo( this.x, this.y - 2 );
ctx.lineTo( this.x, this.y + size );
ctx.stroke();
ctx.fillStyle = this.color;
ctx.translate( this.x, this.y );
ctx.rotate( Math.PI / 4 );
//ctx.fillRect( -size / 2, -size / 2, size / 2, size / 2 );
ctx.beginPath();
ctx.moveTo( 0, 0 );
ctx.arc( -size / 2, -size / 2 + size / 4, size / 4, Math.PI / 2, Math.PI * 3 / 2 );
ctx.arc( -size / 2 + size / 4, -size / 2, size / 4, Math.PI, Math.PI * 2 );
ctx.lineTo( 0, 0 );
ctx.fill();
ctx.rotate( -Math.PI / 4 );
ctx.translate( -this.x, -this.y );
ctx.translate( this.x, this.y + size + 15 );
ctx.scale( size / this.size, size / this.size );
ctx.fillStyle = '#eee';
for( var i = 0; i < this.phrase.length; ++i )
ctx.fillText( this.phrase[ i ], this.lengths[ i ], i * 15 );
ctx.scale( this.size / size, this.size / size );
ctx.translate( -this.x, -( this.y + size + 15 ) );
if( this.y < -size * 3 )
this.reset();
}
function anim(){
window.requestAnimationFrame( anim );
ctx.fillStyle = '#222';
ctx.fillRect( 0, 0, w, h );
if( balloons.length < opts.balloons && Math.random() < .01 )
balloons.push( new Balloon );
for( var i = 0; i < balloons.length; ++i )
balloons[ i ].step();
}
anim();script>
body>
html>