HTML5 Canvas に花火が咲く特殊効果を実装_html5 チュートリアルスキル-H5 チュートリアル-php.cn

この記事では、HTML5 Canvas で実装された、無料で安全で環境に優しい花火の特殊効果を紹介します。

効果は次のとおりです:

コードは次のとおりです:

XML/HTML コードコンテンツをクリップボードにコピー

>
<html>
<頭>
<title>キャンバス实现放烟花特效タイトル>
<meta charset="utf- 8">
<メタ http-equiv=" X-UA 互換" コンテンツ="IE=edge">
<メタ名前="ビューポート" コンテンツ="width=デバイスの幅,height=デバイスの高さ,初期スケール=1.0,最大スケール=1.0 ,user-scalable=no">
<スタイルタイプ="text/ css">
html,body{高さ:100%;マージン:0;パディング:0}
ul,li{text-indent:0;text-decoration:none;margin:0;padding:0}
img{border:0}
body{background-color:#000;color:#999;font:100%/18px helvetica, arial, sans-serif}
canvas{cursor:crosshair;display:block;left:0;position:absolute;top:0;z-index:20}
#header img{width:100%; 高さ:20%;}
#bg img{width:100%; 高さ:80%;}
#header,#bg{position:fixed;left:0;right:0;z-index:10}
#header{top:0}
#bg{位置:固定;z-index:1;bottom:0}
オーディオ{位置:固定;表示:なし;下:0;左:0;右:0;幅:100%;z-index:5}
スタイル>
頭>
<ボディ>
<div id="bg" >
<img id="bgimg" src="http://img.ivsky.com/img/tupian/pre/201508/02/yuzhou_xingkong_yu_yueliang-006 .jpg">
div>
<script src="http: //cdn.bootcss.com/jquery/2.2.0/jquery.min.js">スクリプト >
<スクリプト>
$(function(){
var 花火 = 関数(){
var 自分 = これ;
// 产生烟花随机数
var rand = function(rMi, rMa){
//按位取反运算符
return ~~((Math.random()*(rMa-rMi 1)) rMi);
},hitTest = 関数(x1, y1, w1, h1, x2, y2, w2, h2){
return !(x1 w1 < x2 || x2 w2 < x1 || y1 h1 y2 || y2 h2 < y1);
};
//请求アニメーション画帧
window.requestAnimFrame=function(){
return window.requestAnimationFrame
||window.webkitRequestAnimationFrame
||window.mozRequestAnimationFrame
||window.oRequestAnimationFrame
||window.msRequestAnimationFrame
||function(コールバック){
window.setTimeout(callback,1000/60);
}
}();
self.init = 関数(){
self.canvas = document.createElement('canvas');
//canvas 全屏
selfself.canvas.width = self.cw = $(window ).innerWidth();
selfself.canvas.height = self.ch = $(window ).innerHeight();
self.particles = [];
self.partCount = 150;
self.fireworks = [];
selfself.mx = self.cw/2;
selfself.my = self.ch/2;
self.currentHue = 30;
self.partSpeed = 5;
self.partSpeedVariance = 10;
self.partWind = 50;
self.partFriction = 5;
self.partGravity = 1;
self.hueMin = 0;
self.hueMax = 360;
self.fworkSpeed = 4;
self.fworkAccel = 10;
self.hueVariance = 30;
self.flickerDensity = 25;
self.showShockwave = true;
self.showTarget = false;
self.clearAlpha = 25;
$(document.body).append(self.canvas);
selfself.ctx = self.canvas.getContext('2d');
self.ctx.lineCap = 'round';
self.ctx.lineJoin = 'round';
self.lineWidth = 1;
self.bindEvents();
self.canvasLoop();
self.canvas.onselectstart = function() {
false を返します。
};
};
// 创建粒子
self.createParticles = function(x,y, hue){
var カウントダウン = self.partCount;
while(カウントダウン--){
var newParticle = {
x: x,
y: y,
coordLast: [
{x: x, y: y}、
{x: x, y: y}、
{x: x, y: y}
]、
角度: rand(0, 360),
speed: rand(((self.partSpeed - self.partSpeedVariance) <= 0) ? 1 : self.partSpeed - self.partSpeedVariance, (self .partSpeed self.partSpeedVariance))、
摩擦: 1 - self.partFriction/100,
gravity: self.partGravity/2,
hue: rand(hue-self.hueVariance, hue self.hueVariance),
明るさ: rand(50, 80),
アルファ: rand(40,100)/100,
減衰: rand(10, 50)/1000,
風: (rand(0, self.partWind) - (self.partWind/2))/25,
lineWidth: self.lineWidth
};
self.particles.push(newParticle);
}
};
// 粒子を更新
self.updateParticles = 関数(){
var i = self.particles.length;
while(i--){
var p = self.particles[i];
var ラジアン = p.angle * Math.PI / 180;
var vx = Math.cos(ラジアン) * p.speed;
var vy = Math.sin(ラジアン) * p.speed;
p.速度 *= p.摩擦;
p.coordLast[2].x = p.coordLast[1].x;
p.coordLast[2].y = p.coordLast[1].y;
p.coordLast[1].x = p.coordLast[0].x;
p.coordLast[1].y = p.coordLast[0].y;
p.coordLast[0].x = p.x;
p.coordLast[0].y = p.y;
p.x = vx;
p.y = vy;
p.y = p.gravity;
p.angle = p.wind;
p.alpha -= p.decay;
if(!hitTest(0,0,self.cw,self.ch,p.x-p.radius, p.y-p.radius, p.radius*2, p.radius*2) || p .alpha < .05){
self.particles.splice(i, 1);
}
};
};
// 绘制粒子
self.drawParticles = 関数(){
var i = self.particles.length;
while(i--){
var p = self.particles[i];
var coordRand = (rand(1,3)-1);
self.ctx.beginPath();
self.ctx.moveTo(Math.round(p.coordLast[coordRand].x), Math.round(p.coordLast[coordRand].y));
self.ctx.lineTo(Math.round(p.x), Math.round(p.y));
self.ctx.closePath();
self.ctx.bloodStyle = 'hsla(' p.hue ', 100%, ' p .brightness '%, ' p.alpha ')';
self.ctx.ストローク();
if(self.flickerDensity > 0){
var inverseDensity = 50 - self.flickerDensity;
if(rand(0, inverseDensity) === inverseDensity){
self.ctx.beginPath();
self.ctx.arc(Math.round(p.x), Math.round(p.y), rand(p.lineWidth,p.lineWidth 3)/2, 0, Math.PI*2, false)
self.ctx.closePath();
var randrandAlpha = rand(50,100)/100;
self.ctx.fillStyle = 'hsla(' p.hue ', 100%, ' p .brightness '%, ' randAlpha ')';
self.ctx.fill();
}
}
};
};
// 创建烟花
self.createFireworks = function(startX, startY, targetX, targetY){
var newFirework = {
x: startX,
y: startY,
startX: startX,
startY: startY,
hitX: false,
hitY: false,
coordLast: [
{x: startX, y: startY},
{x: startX, y: startY},
{x: startX, y: startY}
]、
targetX: targetX,
targetY: targetY,
speed: self.fworkSpeed,
angle: Math.atan2(targetY - startY, targetX - startX),
shockwaveAngle: Math.atan2(targetY - startY, targetX - startX) (90*(Math.PI/180)),
加速度: self.fworkAccel/100,
色相: self.currentHue、
明るさ: rand(50, 80),
アルファ: rand(50,100)/100,
lineWidth: self.lineWidth
};
self.fireworks.push(newFirework);
};
// 更新烟花
self.updateFireworks = function(){
var i = self.fireworks.length;
while(i--){
var f = self.fireworks[i];
self.ctx.lineWidth = f.lineWidth;
vx = Math.cos(f.angle) * f.speed,
vy = Math.sin(f.angle) * f.speed;
f.速度 *= 1 f.加速度;
f.coordLast[2].x = f.coordLast[1].x;
f.coordLast[2].y = f.coordLast[1].y;
f.coordLast[1].x = f.coordLast[0].x;
f.coordLast[1].y = f.coordLast[0].y;
f.coordLast[0].x = f.x;
f.coordLast[0].y = f.y;
if(f.startX >= f.targetX){
if(f.x vx <= f.targetX){
ff.x = f.targetX;
f.hitX = true;
} else {
f.x = vx;
}
} else {
if(f.x vx >= f.targetX){
ff.x = f.targetX;
f.hitX = true;
} else {
f.x = vx;
}
}
if(f.startY >= f.targetY){
if(f.y vy <= f.targetY){
ff.y = f.targetY;
f.hitY = true;
} else {
f.y = vy;
}
} else {
if(f.y vy >= f.targetY){
ff.y = f.targetY;
f.hitY = true;
} else {
f.y = vy;
}
}
if(f.hitX && f.hitY){
self.createParticles(f.targetX, f.targetY, f.hue);
self.fireworks.splice(i, 1);
}
};
};
// 绘制烟花
self.drawFireworks = 関数(){
var i = self.fireworks.length;
self.ctx.globalCompositeOperation = 'lighter';
while(i--){
var f = self.fireworks[i];
self.ctx.lineWidth = f.lineWidth;
var coordRand = (rand(1,3)-1);
self.ctx.beginPath();
self.ctx.moveTo(Math.round(f.coordLast[coordRand].x), Math.round(f.coordLast[coordRand].y));
self.ctx.lineTo(Math.round(f.x), Math.round(f.y));
self.ctx.closePath();
self.ctx.bloodStyle = 'hsla(' f.hue ', 100%, ' f .brightness '%, ' f.alpha ')';
self.ctx.ストローク();
if(self.showTarget){
self.ctx.save();
self.ctx.beginPath();
self.ctx.arc(Math.round(f.targetX), Math.round(f.targetY), rand(1,8), 0, Math.PI*2, false)
self.ctx.closePath();
self.ctx.lineWidth = 1;
self.ctx.ストローク();
self.ctx.restore();
}
if(self.showShockwave){
self.ctx.save();
self.ctx.translate(Math.round(f.x), Math.round(f.y));
self.ctx.rotate(f.shockwaveAngle);
self.ctx.beginPath();
self.ctx.arc(0, 0, 1*(f.speed/5), 0, Math.PI, true);
self.ctx.bloodStyle = 'hsla(' f.hue ', 100%, ' f .brightness '%, ' rand(25, 60)/100 ')';
self.ctx.lineWidth = f.lineWidth;
self.ctx.ストローク();
self.ctx.restore();
}
};
};
// 绑定イベント
self.bindEvents = function(){
$(window).on('resize', function(){
clearTimeout(self.timeout);
self.timeout = setTimeout(function() {
selfself.canvas.width = self.cw = $(window ).innerWidth();
selfself.canvas.height = self.ch = $(window ).innerHeight();
self.ctx.lineCap = 'round';
self.ctx.lineJoin = 'round';
}, 100);
});
$(self.canvas).on('mousedown', function(e){
self.mx = e.pageX - self.canvas.offsetLeft;
self.my = e.pageY - self.canvas.offsetTop;
self.currentHue = rand(self.hueMin, self.hueMax);
self.createFireworks(self.cw/2, self.ch, self.mx, self.my);
$(self.canvas).on('mousemove.fireworks', function(e){
self.mx = e.pageX - self.canvas.offsetLeft;
self.my = e.pageY - self.canvas.offsetTop;
self.currentHue = rand(self.hueMin, self.hueMax);
self.createFireworks(self.cw/2, self.ch, self.mx, self.my);
});
});
$(self.canvas).on('mouseup', function(e){
$(self.canvas).off('mousemove.fireworks');
});
};
self.clear = 関数(){
self.particles = [];
self.fireworks = [];
self.ctx.clearRect(0, 0, self.cw, self.ch);
};
self.canvasLoop = function(){
requestAnimFrame(self.canvasLoop, self.canvas);
self.ctx.globalCompositeOperation = 'destination-out';
self.ctx.fillStyle = 'rgba(0,0,0,' self.clearAlpha/ 100 ')';
self.ctx.fillRect(0,0,self.cw,self.ch);
self.updateFireworks();
self.updateParticles();
self.drawFireworks();
self.drawParticles();
};
self.init();
}
var fworks = new
腳本>
畫布寬度=寬度= 🎜> 身高="449">> >
身體>
html>