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javascriptopacity

Adding opacity to particles in javascript?


I'm looking for some help as to how I can make the particles in this script to have an option for opacity. I've tried replacing the hex color number with an rgb with opacity, but it breaks the code.

Sorry the code is poorly formatted, but this is all I have to work with, and don't know much javascript. Thanks for any help with this.

<script type="text/javascript">
!function(a){var b="object"==typeof self&&self.self===self&&self||"object"==typeof global&&global.global===global&&global;"function"==typeof define&&define.amd?define(["exports"],function(c){b.ParticleNetwork=a(b,c)}):"object"==typeof module&&module.exports?module.exports=a(b,{}):b.ParticleNetwork=a(b,{})}(function(a,b){var c=function(a){this.canvas=a.canvas,this.g=a.g,this.particleColor=a.options.particleColor,this.x=Math.random()*this.canvas.width,this.y=Math.random()*this.canvas.height,this.velocity={x:(Math.random()-.5)*a.options.velocity,y:(Math.random()-.5)*a.options.velocity}};return c.prototype.update=function(){(this.x>this.canvas.width+20||this.x<-20)&&(this.velocity.x=-this.velocity.x),(this.y>this.canvas.height+20||this.y<-20)&&(this.velocity.y=-this.velocity.y),this.x+=this.velocity.x,this.y+=this.velocity.y},c.prototype.h=function(){this.g.beginPath(),this.g.fillStyle=this.particleColor,this.g.globalAlpha=.7,this.g.arc(this.x,this.y,1.5,0,2*Math.PI),this.g.fill()},b=function(a,b){this.i=a,this.i.size={width:this.i.offsetWidth,height:this.i.offsetHeight},b=void 0!==b?b:{},this.options={particleColor:void 0!==b.particleColor?b.particleColor:"#fff",background:void 0!==b.background?b.background:"#1a252f",interactive:void 0!==b.interactive?b.interactive:!0,velocity:this.setVelocity(b.speed),density:this.j(b.density)},this.init()},b.prototype.init=function(){if(this.k=document.createElement("div"),this.i.appendChild(this.k),this.l(this.k,{position:"absolute",top:0,left:0,bottom:0,right:0,"z-index":1}),/(^#[0-9A-F]{6}$)|(^#[0-9A-F]{3}$)/i.test(this.options.background))this.l(this.k,{background:this.options.background});else{if(!/\.(gif|jpg|jpeg|tiff|png)$/i.test(this.options.background))return console.error("Please specify a valid background image or hexadecimal color"),!1;this.l(this.k,{background:'url("'+this.options.background+'") no-repeat center',"background-size":"cover"})}if(!/(^#[0-9A-F]{6}$)|(^#[0-9A-F]{3}$)/i.test(this.options.particleColor))return console.error("Please specify a valid particleColor hexadecimal color"),!1;this.canvas=document.createElement("canvas"),this.i.appendChild(this.canvas),this.g=this.canvas.getContext("2d"),this.canvas.width=this.i.size.width,this.canvas.height=this.i.size.height,this.l(this.i,{position:"relative"}),this.l(this.canvas,{"z-index":"20",position:"relative"}),window.addEventListener("resize",function(){return this.i.offsetWidth===this.i.size.width&&this.i.offsetHeight===this.i.size.height?!1:(this.canvas.width=this.i.size.width=this.i.offsetWidth,this.canvas.height=this.i.size.height=this.i.offsetHeight,clearTimeout(this.m),void(this.m=setTimeout(function(){this.o=[];for(var a=0;a<this.canvas.width*this.canvas.height/this.options.density;a++)this.o.push(new c(this));this.options.interactive&&this.o.push(this.p),requestAnimationFrame(this.update.bind(this))}.bind(this),500)))}.bind(this)),this.o=[];for(var a=0;a<this.canvas.width*this.canvas.height/this.options.density;a++)this.o.push(new c(this));this.options.interactive&&(this.p=new c(this),this.p.velocity={x:0,y:0},this.o.push(this.p),this.canvas.addEventListener("mousemove",function(a){this.p.x=a.clientX-this.canvas.offsetLeft,this.p.y=a.clientY-this.canvas.offsetTop}.bind(this)),this.canvas.addEventListener("mouseup",function(a){this.p.velocity={x:(Math.random()-.5)*this.options.velocity,y:(Math.random()-.5)*this.options.velocity},this.p=new c(this),this.p.velocity={x:0,y:0},this.o.push(this.p)}.bind(this))),requestAnimationFrame(this.update.bind(this))},b.prototype.update=function(){this.g.clearRect(0,0,this.canvas.width,this.canvas.height),this.g.globalAlpha=1;for(var a=0;a<this.o.length;a++){this.o[a].update(),this.o[a].h();for(var b=this.o.length-1;b>a;b--){var c=Math.sqrt(Math.pow(this.o[a].x-this.o[b].x,2)+Math.pow(this.o[a].y-this.o[b].y,2));c>120||(this.g.beginPath(),this.g.strokeStyle=this.options.particleColor,this.g.globalAlpha=(120-c)/120,this.g.lineWidth=.7,this.g.moveTo(this.o[a].x,this.o[a].y),this.g.lineTo(this.o[b].x,this.o[b].y),this.g.stroke())}}0!==this.options.velocity&&requestAnimationFrame(this.update.bind(this))},b.prototype.setVelocity=function(a){return"fast"===a?1:"slow"===a?.33:"none"===a?0:.26},b.prototype.j=function(a){return"high"===a?5e3:"low"===a?2e4:isNaN(parseInt(a,10))?1e4:a},b.prototype.l=function(a,b){for(var c in b)a.style[c]=b[c]},b});

// Initialisation

var canvasDiv = document.getElementById('particle-canvas');
var options = {
  particleColor: '#FFF',
  background: '/wp-content/uploads/2018/09/gradient-top-solo-01-with-white.jpg',
  interactive: false,
  speed: 'slow',
  density: 'high'
};
var particleCanvas = new ParticleNetwork(canvasDiv, options);


Solution

  • The script you're using is doing validation on the color and background format.

    It's only allowing hexadecimal colors (#FFF or #048CEF for instance) and image files ending with gif|jpg|jpeg|tiff|png.

    Without this validation the script would use rgba colors the same way it uses hex colors.

    This validation is done by the use of regular expressions:

    /(^#[0-9A-F]{6}$)|(^#[0-9A-F]{3}$)/i
    // is validating the color
    

    and

    /\.(gif|jpg|jpeg|tiff|png)$/i
    // is validating the file extension
    

    If you want the script to allow for rgba colors you can modify the regular expression of the color by adding an alternative to it:

    (^rgba?\(\s*[0-9]+\s*,\s*[0-9]+\s*,\s*[0-9]+\s*(?:,\s*[0-9]+(?:\.[0-9]+)?\s*)?\)$)
    // this validates loosely rgb and rgba formats
    

    @Karthick has offered you a modified script, I'm offering you the why it's not working, and how to fix it by your own means.

    Here is a good resource for validating and testing regular exressions.