Team:TAS Taipei/js/field homepage.js

From 2014hs.igem.org

var COLORS, FRICTION, GRAVITY, MAX_FORCE, NUM_PARTICLES, Particle, TAIL_LENGTH;

 TAIL_LENGTH = 8;

 MAX_FORCE = 40;

 FRICTION = 0.48;

 GRAVITY = 9.81*2;

 COLORS = ['#fff'];

 Particle = (function() {
   function Particle(x, y, mass) {
     this.x = x != null ? x : 0.0;
     this.y = y != null ? y : 0.0;
     this.mass = mass != null ? mass : 1.0;
     this.tail = [];
     this.radius = this.mass * 0.25;
     this.charge = random([-1, 1]);
     this.color = random(COLORS);
     this.fx = this.fy = 0.0;
     this.vx = this.vy = 0.0;
   }

   return Particle;

 })();

var sketchItem = Sketch.create({

   container: document.querySelector( '.canvas-container' ),
   particles: [],
   interval: 3,
   autostart: false,
   autopause: false,
   retina: false,
   setup: function() {
     var i, m, x, y, _i, _results;
     _results = [];
     for (i = _i = 0; _i <= NUM_PARTICLES; i = _i += 1) {
       x = random(this.width);
       y = random(this.height);
       m = random(8.0, 14.0);
       _results.push(this.particles.push(new Particle(x, y, m)));
     }
     return _results;
   },
   draw: function() {
     var a, b, dSq, dst, dx, dy, f, fx, fy, i, j, len, p, rad, _i, _j, _k, _len, _ref, _ref1, _results;
     this.lineCap = this.lineJoin = 'round';
     _results = [];
     for (i = _i = 0; _i <= NUM_PARTICLES; i = _i += 1) {
       a = this.particles[i];
       if (random() < 0.5) {
         a.charge = -a.charge;
       }
       for (j = _j = _ref = i + 1; _j <= NUM_PARTICLES; j = _j += 1) {
         b = this.particles[j];
         dx = b.x - a.x;
         dy = b.y - a.y;
         dst = sqrt(dSq = (dx * dx + dy * dy) + 0.1);
         rad = a.radius + b.radius;
         if (dst >= rad) {
           len = 1.0 / dst;
           fx = dx * len;
           fy = dy * len;
           f = min(MAX_FORCE, (GRAVITY * a.mass * b.mass) / dSq);
           a.fx += f * fx * b.charge;
           a.fy += f * fy * b.charge;
           b.fx += -f * fx * a.charge;
           b.fy += -f * fy * a.charge;
         }
       }
       a.vx += a.fx;
       a.vy += a.fy;
       a.vx *= FRICTION;
       a.vy *= FRICTION;
       a.tail.unshift({
         x: a.x,
         y: a.y
       });
       if (a.tail.length > TAIL_LENGTH) {
         a.tail.pop();
       }
       a.x += a.vx;
       a.y += a.vy;
       a.fx = a.fy = 0.0;
       if (a.x > this.width + a.radius) {
         a.x = -a.radius;
         a.tail = [];
       } else if (a.x < -a.radius) {
         a.x = this.width + a.radius;
         a.tail = [];
       }
       if (a.y > this.height + a.radius) {
         a.y = -a.radius;
         a.tail = [];
       } else if (a.y < -a.radius) {
         a.y = this.height + a.radius;
         a.tail = [];
       }
       this.strokeStyle = a.color;
       this.lineWidth = a.radius * 0.1;
       this.beginPath();
       this.moveTo(a.x, a.y);
       _ref1 = a.tail;
       for (_k = 0, _len = _ref1.length; _k < _len; _k++) {
         p = _ref1[_k];
         this.lineTo(p.x, p.y);
       }
       _results.push(this.stroke());
     }
     return _results;
   }
 });