HTML5 Canvas realisiert die Spezialeffekte eines blühenden Feuerwerks-H5-Tutorial-php.cn

Dies ist eine wunderschöne HTML5-Canvas-Animation. Sie simuliert die Animationsspezialeffekte von Feuerwerkskörpern, die in unserem Leben aufblühen. Wenn Sie interessiert sind, analysieren wir kurz den Prozess und den Code Freunde können sich auf
Dieser Artikel bietet Ihnen einen kostenlosen, sicheren und umweltfreundlichen Feuerwerks-Spezialeffekt, der in HTML5 Canvas implementiert ist.
Der Effekt ist wie folgt:
Der Code ist wie folgt:
<!DOCTYPE HTML>
<html>
  <head>
    <title>Canvas 实现放烟花特效</title>
 <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,height=device-height,inital-scale=1.0,maximum-scale=1.0,user-scalable=no">
    <style type="text/css">
  html,body{height:100%;margin:0;padding: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%; height:20%;}   
  #bg img{width:100%; height:80%;}   
  #header,#bg{position:fixed;left:0;right:0;z-index:10}   
  #header{top:0}   
  #bg{position:fixed;z-index:1;bottom:0}   
  audio{position:fixed;display:none;bottom:0;left:0;right:0;width:100%;z-index:5}   
 </style>
  </head>
  <body>
 <p id="bg">
  <img id="bgimg" src="http://img.ivsky.com/img/tupian/pre/201508/02/yuzhou_xingkong_yu_yueliang-006.jpg">
 </p>
 <script src="http://cdn.bootcss.com/jquery/2.2.0/jquery.min.js"></script>
 <script>
  $(function(){   
   var Fireworks = function(){   
    var self = this;   
    // 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 = function(x1, y1, w1, h1, x2, y2, w2, h2){   
     return !(x1 + w1 < x2 || x2 + w2 < x1 || y1 + h1 < y2 || y2 + h2 < y1);   
    };   
    //请求动画帧   
    window.requestAnimFrame=function(){   
     return window.requestAnimationFrame   
      ||window.webkitRequestAnimationFrame   
      ||window.mozRequestAnimationFrame   
      ||window.oRequestAnimationFrame   
      ||window.msRequestAnimationFrame   
      ||function(callback){   
       window.setTimeout(callback,1000/60);   
      }   
    }();   
    self.init = function(){    
     self.canvas = document.createElement(&#39;canvas&#39;);     
     //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(&#39;2d&#39;);   
     self.ctx.lineCap = &#39;round&#39;;   
     self.ctx.lineJoin = &#39;round&#39;;   
     self.lineWidth = 1;   
     self.bindEvents();      
     self.canvasLoop();   
     self.canvas.onselectstart = function() {   
      return false;   
     };   
    };     
    // 创建粒子   
    self.createParticles = function(x,y, hue){   
     var countdown = self.partCount;   
     while(countdown--){   
      var newParticle = {   
       x: x,   
       y: y,   
       coordLast: [   
        {x: x, y: y},   
        {x: x, y: y},   
        {x: x, y: y}   
       ],   
       angle: rand(0, 360),   
       speed: rand(((self.partSpeed - self.partSpeedVariance) <= 0) ? 1 : self.partSpeed - self.partSpeedVariance, (self.partSpeed + self.partSpeedVariance)),   
       friction: 1 - self.partFriction/100,   
       gravity: self.partGravity/2,   
       hue: rand(hue-self.hueVariance, hue+self.hueVariance),   
       brightness: rand(50, 80),   
       alpha: rand(40,100)/100,   
       decay: rand(10, 50)/1000,   
       wind: (rand(0, self.partWind) - (self.partWind/2))/25,   
       lineWidth: self.lineWidth   
      };       
      self.particles.push(newParticle);   
     }   
    };   
    // 更新粒子   
    self.updateParticles = function(){   
     var i = self.particles.length;   
     while(i--){   
      var p = self.particles[i];   
      var radians = p.angle * Math.PI / 180;   
      var vx = Math.cos(radians) * p.speed;   
      var vy = Math.sin(radians) * p.speed;   
      p.speed *= p.friction;   
      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 = function(){   
     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.strokeStyle = &#39;hsla(&#39;+p.hue+&#39;, 100%, &#39;+p.brightness+&#39;%, &#39;+p.alpha+&#39;)&#39;;   
      self.ctx.stroke();       
      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 = &#39;hsla(&#39;+p.hue+&#39;, 100%, &#39;+p.brightness+&#39;%, &#39;+randAlpha+&#39;)&#39;;   
        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)),   
      acceleration: self.fworkAccel/100,   
      hue: self.currentHue,   
      brightness: rand(50, 80),   
      alpha: 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.speed *= 1 + f.acceleration;       
      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 = function(){   
     var i = self.fireworks.length;   
     self.ctx.globalCompositeOperation = &#39;lighter&#39;;   
     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.strokeStyle = &#39;hsla(&#39;+f.hue+&#39;, 100%, &#39;+f.brightness+&#39;%, &#39;+f.alpha+&#39;)&#39;;   
      self.ctx.stroke();    
      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.stroke();   
       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.strokeStyle = &#39;hsla(&#39;+f.hue+&#39;, 100%, &#39;+f.brightness+&#39;%, &#39;+rand(25, 60)/100+&#39;)&#39;;   
       self.ctx.lineWidth = f.lineWidth;   
       self.ctx.stroke();   
       self.ctx.restore();   
      }   
     };   
    };   
    // 绑定事件   
    self.bindEvents = function(){   
     $(window).on(&#39;resize&#39;, 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 = &#39;round&#39;;   
       self.ctx.lineJoin = &#39;round&#39;;   
      }, 100);   
     });   
     $(self.canvas).on(&#39;mousedown&#39;, 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(&#39;mousemove.fireworks&#39;, 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(&#39;mouseup&#39;, function(e){   
      $(self.canvas).off(&#39;mousemove.fireworks&#39;);            
     });   
    };   
    self.clear = function(){   
     self.particles = [];   
     self.fireworks = [];   
     self.ctx.clearRect(0, 0, self.cw, self.ch);   
    };   
    self.canvasLoop = function(){   
     requestAnimFrame(self.canvasLoop, self.canvas);      
     self.ctx.globalCompositeOperation = &#39;destination-out&#39;;   
     self.ctx.fillStyle = &#39;rgba(0,0,0,&#39;+self.clearAlpha/100+&#39;)&#39;;   
     self.ctx.fillRect(0,0,self.cw,self.ch);   
     self.updateFireworks();   
     self.updateParticles();   
     self.drawFireworks();      
     self.drawParticles();   
    };   
    self.init();     
   }   
   var fworks = new Fireworks();   
   $(&#39;#info-toggle&#39;).on(&#39;click&#39;, function(e){   
    $(&#39;#info-inner&#39;).stop(false, true).slideToggle(100);   
    e.preventDefault();   
   });    
  });   
 </script>
 <canvas width="1400" height="449"></canvas>
  </body>
</html>
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Ja Lassen Sie sich von den leistungsstarken Effekten von HTML5 nicht überraschen, genießen Sie es einfach.
Das Obige ist der gesamte Inhalt dieses Artikels. Ich hoffe, er wird für das Studium aller hilfreich sein. Weitere verwandte Inhalte finden Sie auf der chinesischen PHP-Website.
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Das obige ist der detaillierte Inhalt vonHTML5 Canvas realisiert die Spezialeffekte eines blühenden Feuerwerks. Für weitere Informationen folgen Sie bitte anderen verwandten Artikeln auf der PHP chinesischen Website!