简易demo送给母亲，祝所有母亲节日快乐！
程序员文章站
2022-07-13 17:51:35
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1.效果
2.源码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Happy Mothers's Day</title>
<script src="http://www.jq22.com/jquery/jquery-1.10.2.js"></script>
<script src="https://libs.baidu.com/jquery/1.10.2/jquery.min.js"></script>
<style>
canvas {
position: absolute;
top: 0;
left: 0;
}
</style>
</head>
<body>
<canvas id="c">
</canvas>
<img src="/static/images/mother.jpg" id="img" style="display: none"/>
<script>
var w = c.width = window.innerWidth,
h = c.height = window.innerHeight,
ctx = c.getContext( '2d' ),
opts = {
phrases: [ "You're the best", "Every day,\nYou're beautiful","You're better than them,\nwhoever they are", "You're so amazing","A mother's love \nis the greatest power in the world"],
balloons: 10,
baseVelY: -1,
addedVelY: -1,
baseVelX: -.25,
addedVelX: .5,
baseSize: 70,
addedSize: 20,
baseSizeAdder: 2,
addedSizeAdder: 2,
baseIncrementer: .01,
addedIncrementer: .03,
baseHue: -10,
addedHue: 30,
font: '20px 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 = '#de7678';
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 = '#de7678';
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 );
var img=document.getElementById("img");
ctx.drawImage(img,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>