// Cloned by Mathias Bazin on 24 Jul 2018 from World "Scare the Fishes" by Mathias Bazin 
// Please leave this clone trail here.
 

//base code from
// Daniel Shiffman
// http://codingtra.in
// http://patreon.com/codingtrain
// Code for: https://youtu.be/BjoM9oKOAKY


function Particle() {
  this.pos = createVector(random(width), random(height));
  this.vel = createVector(0, 0);
  this.acc = createVector(0, 0);
  this.maxspeed = 4;
  this.h = random(255);
  this.prev = [];

  this.update = function() {
    this.vel.add(this.acc);
    if(this.vel.mag() > this.maxspeed) this.vel.mult(0.7);
    this.pos.add(this.vel);
    this.acc.mult(0);
    
    this.prev.unshift(this.pos.copy());
    if(this.prev.length >= 5)
    {
        this.prev.pop();
    }
    
  };

  this.follow = function(vectors) {
    var x = floor(this.pos.x / scl);
    var y = floor(this.pos.y / scl);
    var index = x + y * cols;
    var force = vectors[index];
    this.applyForce(force);
  };

  this.applyForce = function(force) {
    this.acc.add(force);
  };

  this.show = function() {
    stroke(this.h, 255, 255, 100);
    strokeWeight(3);
    for (let p of this.prev)
    {   
       point(p.x,p.y)
    }
    strokeWeight(6);
    point(this.pos.x, this.pos.y);
    
  };

 

  this.edges = function() {
    if (this.pos.x > width) {
      this.pos.x = 0;
      
    }
    if (this.pos.x < 0) {
      this.pos.x = width;
      
    }
    if (this.pos.y > height) {
      this.pos.y = 0;
      
    }
    if (this.pos.y < 0) {
      this.pos.y = height;
      
    }

  };

}

function World() 
{ 
	
	this.newRun = function()
	{
 	
				threeworld.init (  "white"  ); 
	};


}


var inc = 0.1;
var scl = 10;
var cols, rows;

var zoff = 0;

var fr;

var particles = [];

var flowfield;

let drawForceField = false;
let radius = 150;

function aftersetup()      
{
  colorMode(HSB, 255);
  cols = floor(width / scl);
  rows = floor(height / scl);

  flowfield = new Array(cols * rows);

  for (var i = 0; i < 400; i++) {
    particles[i] = new Particle();
  }
}





function draw()             
{
    background(30)
  var yoff = 0;
  for (var y = 0; y < rows; y++) {
    var xoff = 0;
    for (var x = 0; x < cols; x++) {
      var index = x + y * cols;
      var angle = noise(xoff, yoff, zoff) * TWO_PI * 4;
      var v = p5.Vector.fromAngle(angle);
      v.setMag(1);
      flowfield[index] = v;
      xoff += inc;
      stroke(0, 50);
      if(drawForceField)
      {
          push();
          translate(x * scl, y * scl);
          rotate(v.heading());
          strokeWeight(1);
          line(0, 0, scl, 0);
          pop();
      }
    }
    yoff += inc;

    zoff += 0.0003;
  }
  
  for(let y = 0; y<rows; y++)
  {
      for (let x = 0; x < cols; x++) 
      {
          
          let mouse = createVector(mouseX,mouseY);
          let point = createVector(x*scl, y*scl);
          let dist = mouse.dist(point); 
          if(mouseIsPressed)
          {
              if (dist < radius + 200)
              {
                
                    let v = createVector(point.x - mouse.x, point.y - mouse.y);
                    v.setMag(3000000000000/dist);
                    flowfield[x + y*cols] = v;
        
              }
          }
          else
          {
              if (dist < radius)
              {
                
                    let v = createVector(point.x - mouse.x, point.y - mouse.y);
                    v.setMag(300/dist);
                    flowfield[x + y*cols] = v;
        
              }
          }
          
      }
  }

  for (var i = 0; i < particles.length; i++) {
    particles[i].follow(flowfield);
    particles[i].update();
    particles[i].edges();
    particles[i].show();
  }

}