【烟花代码】，情人节，情侣生日礼物代码适用

老规矩，先上效果图
在这里插入图片描述
图片做了加速处理，放樱花的位置，速度完全由点击控制。

1初始化粒子系统

	var Particle = function(x, y, hue){this.x = x;this.y = y;this.coordLast = [{x: x, y: y},{x: x, y: y},{x: x, y: y}];this.angle = rand(0, 360);this.speed = rand(((self.partSpeed - self.partSpeedVariance) <= 0) ? 1 : self.partSpeed - self.partSpeedVariance, (self.partSpeed + self.partSpeedVariance));this.friction = 1 - self.partFriction/100;this.gravity = self.partGravity/2;this.hue = rand(hue-self.hueVariance, hue+self.hueVariance);this.brightness = rand(50, 80);this.alpha = rand(40,100)/100;this.decay = rand(10, 50)/1000;this.wind = (rand(0, self.partWind) - (self.partWind/2))/25;this.lineWidth = self.lineWidth;};

2粒子系统的更新

	Particle.prototype.update = function(index){var radians = this.angle * Math.PI / 180;var vx = Math.cos(radians) * this.speed;var vy = Math.sin(radians) * this.speed + this.gravity;this.speed *= this.friction;this.coordLast[2].x = this.coordLast[1].x;this.coordLast[2].y = this.coordLast[1].y;this.coordLast[1].x = this.coordLast[0].x;this.coordLast[1].y = this.coordLast[0].y;this.coordLast[0].x = this.x;this.coordLast[0].y = this.y;this.x += vx * self.dt;this.y += vy * self.dt;this.angle += this.wind;				this.alpha -= this.decay;if(!hitTest(0,0,self.cw,self.ch,this.x-this.radius, this.y-this.radius, this.radius*2, this.radius*2) || this.alpha < .05){					self.particles.splice(index, 1);	}			};

3粒子系统的画图

	Particle.prototype.draw = function(){var coordRand = (rand(1,3)-1);self.ctx.beginPath();								self.ctx.moveTo(Math.round(this.coordLast[coordRand].x), Math.round(this.coordLast[coordRand].y));self.ctx.lineTo(Math.round(this.x), Math.round(this.y));self.ctx.closePath();				self.ctx.strokeStyle = 'hsla('+this.hue+', 100%, '+this.brightness+'%, '+this.alpha+')';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(this.x), Math.round(this.y), rand(this.lineWidth,this.lineWidth+3)/2, 0, Math.PI*2, false)self.ctx.closePath();var randAlpha = rand(50,100)/100;self.ctx.fillStyle = 'hsla('+this.hue+', 100%, '+this.brightness+'%, '+randAlpha+')';self.ctx.fill();}	}};

4创建烟花例子

self.createParticles = function(x,y, hue){var countdown = self.partCount;while(countdown--){						self.particles.push(new Particle(x, y, hue));}
};

5绑定鼠标时间，mousedown，mouseup

	self.bindEvents = function(){$(window).on('resize', function(){			clearTimeout(self.timeout);self.timeout = setTimeout(function() {self.ctx.lineCap = 'round';self.ctx.lineJoin = 'round';}, 100);});$(self.canvas).on('mousedown', function(e){var randLaunch = rand(0, 5);self.mx = e.pageX - self.canvasContainer.offset().left;self.my = e.pageY - self.canvasContainer.offset().top;self.currentHue = rand(self.hueMin, self.hueMax);self.createFireworks(self.cw/2, self.ch, self.mx, self.my);	$(self.canvas).on('mousemove.fireworks', function(e){var randLaunch = rand(0, 5);self.mx = e.pageX - self.canvasContainer.offset().left;self.my = e.pageY - self.canvasContainer.offset().top;self.currentHue = rand(self.hueMin, self.hueMax);self.createFireworks(self.cw/2, self.ch, self.mx, self.my);									});	});$(self.canvas).on('mouseup', function(e){$(self.canvas).off('mousemove.fireworks');									});}