js实现canvas流体可交互拖拽火焰动画效果代码-html代码-BFW代码库

代码语言：html
所属分类：动画
代码描述：js实现canvas流体可交互拖拽火焰动画效果代码，拖拽可生成新的火焰线。
下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">


    <meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no">
    <style>
        body {
      background-color: rgb(29,29,32);  
    	margin: 0;
    	overflow: hidden;
    	background-repeat: no-repeat;
    }
    .label {
    	position: absolute;
    	top: 0;
    	left: 0;
    	padding: 5px 15px;
    	color: #eee;
    	font-size: 13px;
    	background-color: rgba(0, 0, 0, .15);
    }
    .instructions {
    	position: absolute;
    	bottom: 0%;
    	left: 0;
    	padding: 5px 15px;
    	color: #eee;
    	font-size: 13px;
    	background-color: rgba(0, 0, 0, .15);
    }
    canvas { display:block; }
    canvas_2 { display:block; }
    </style>


</head>

<body>
    <canvas id="canvas" width="0" height="0"></canvas>
    <canvas id="canvas_2" width="0" height="0"></canvas>
    <div class="label">FLUID DYNAMICS</div>
    <div class="instructions">DRAG TO AFFECT CANVAS</div>
</body>
<script type="text/javascript" src="//repo.bfw.wiki/bfwrepo/js/dat.gui-min.js"></script>
<script>
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      const mobile = ( navigator.userAgent.match(/Android/i)
          || navigator.userAgent.match(/webOS/i)
          || navigator.userAgent.match(/iPhone/i)
          //|| navigator.userAgent.match(/iPad/i)
          || navigator.userAgent.match(/iPod/i)
          || navigator.userAgent.match(/BlackBerry/i)
          || navigator.userAgent.match(/Windows Phone/i)
          );
    
    
      //Main display canvas
      var ctx = canvas.getContext("2d");
      //Hidden canvas
      var ctx_2 = canvas_2.getContext("2d");
    
      var width = 300;
      var height = 300;
    
      canvas.width = 550;
      canvas.height = 550;
    
      if(mobile){ 
        width = 100;
        height = 100;
        canvas.width = 300;
        canvas.height = 300;
      }
    
    //Half width and half height for displaying image centrally
    var hwidth = canvas.width/2;
    var hheight = canvas.height/2;
    
    canvas_2.width = canvas.width; 
    canvas_2.height = canvas.height;
    
    var TWO_PI = 2 * Math.PI;
    var scale = canvas.width/width;
    
    var u_ = [];
    var v_ = [];
    var u_old_ = [];
    var v_old_ = [];
    var dens_ = [];
    var dens_old_ = [];
    
    var iterations = 3;
    var dt_ = 0.0001;
    var diff_ = 0.0;
    var visc_ = 0.0;
    var radius = 1;
    var strength = 100;
    if(mobile){
      strength = 50;
    }
    var t = 0;
    
    var animate = true;
    var circle = true;
    var add_velocity = true;
    var add_density = true;
    
    var minvar = 0;
    var maxvar = 100;
    
    var velocity = false;
    var density = true;
    
    var clear_button = {clear:function(){clear(); iterations = 3; radius = 1; strength = 100; if(mobile){strength = 50;}}};
    var gui = new dat.GUI();
    gui.add(this, 'circle');
    gui.add(this, 'iterations').min(1.0).max(5.0).step(1.0).listen();
    gui.add(this, 'density').listen().onChange(function(value){velocity = false; density = true;});
    gui.add(this, 'velocity').listen().onChange(function(value){density  = false; velocity = true;});
    gui.add(this, 'add_density');
    gui.add(this, 'add_velocity');
    gui.add(this, 'radius').min(1.0).max(10.0).step(1.0).listen();
    gui.add(this, 'strength').min(1.0).max(1000.0).step(10.0).listen();
    gui.add(this, 'visc_').min(0.0).max(1.0).step(0.0001).listen();
    gui.add(this, 'diff_').min(0.0).max(1.0).step(0.0001).listen();
    gui.add(clear_button, 'clear');
    
    gui.close();
    
    
    function clear(){
      for(i = 0; i < (width+2)*(height+2); i++){
        u_[i] = 0;
        v_[i] = 0;
        u_old_[i] = 0;
        v_old_[i] = 0;
        dens_[i] = 0;
        dens_old_[i] = 0;
      }
    }
    
    
    function IX(i,j){
      return j * (width) + i;
    }
    
    function set_bnd (b, x){
      for(i=1; i<=height; i++) {
        x[IX(0, i)]      = 0;
        x[IX(width+1,i)] = 0;
    
        x[IX(i, 0)]      = 0;
        x[IX(i,width+1)] = 0;
      }
    
      x[IX(0, 0)] = 0.5*(x[IX(1, 0)]+x[IX(0, 1)]); 
      x[IX(0,width+1)] = 0.5*(x[IX(1,width+1)]+x[IX(0, height)]); 
      x[IX(width+1, 0)] = 0.5*(x.........完整代码请登录后点击上方下载按钮下载查看