var lBlobs=[];
var numLBlobs=10;
var disturbers=[];
var numDisturbers=10;
var disturbLen=100;
var disturbA=0
var ox=0, oy=0;
var wp;
var ts=200;


function setup() {
  createCanvas(windowWidth, windowHeight);
  disturbLen=height/6;
  var offX=width/2-8*height/25;
  var offY=height/2-8*height/25;
  for(var j=0; j<16; j++){
    for(var i=0; i<16; i++){
      lBlobs.push(new LiquidBlob(offX+j*height/25, offY+i*height/25, height/25, 0.1, 0.95));
    }
  }
  colorMode(HSB);
}

function updateDisturbers(){
  for(var i=0; i<numDisturbers; i++){
    disturbers[i]={
      x:mouseX+cos(disturbA+TWO_PI/numDisturbers*i)*disturbLen/2,
      y:mouseY+sin(disturbA+TWO_PI/numDisturbers*i)*disturbLen/2
    };
  }
}

function draw() {
  background(20);
  lBlobs.forEach(function(lBlob){
    lBlob.show();
  });
  disturbA+=0.01;
  updateDisturbers();
  textAlign(CENTER);
  textSize(height/16);
  fill(30,80,100,0.4);
  noStroke();
  text("move mouse over the cells",width/2, height*0.85);
}

function mouseMoved(){
  ox=width/2+(mouseX-width/2)*2;
  oy=mouseY;
}

function LiquidBlob(x,y,r,s,d){
  var cells=[];
  var numCells=20;
  var verts=[];
  
 for(var i=0; i<numCells; i++){
    // cells[i]=new Cell(i*width/numCells,y+(y-r),s,d);
    cells[i]=new Cell(i, x+cos(TWO_PI*i/numCells)*r, y+sin(TWO_PI*i/numCells)*r, s, d);
    if(i>0){
      cells[i].prevCell=cells[i-1];
      cells[i].setPrevDist();
      cells[i-1].nextCell=cells[i];
      cells[i-1].setNextDist();
    }
  }
  cells[numCells-1].nextCell=cells[0];
  cells[numCells-1].setNextDist();
  cells[0].prevCell=cells[numCells-1];
  cells[0].setPrevDist();
  
  this.show=function(){
    verts=[];
    var velAgg=0;
    cells.forEach(function(cell){
      // cell.show();
      // cell.repel();
      cell.repelMany();
      cell.neighbourTension();
      cell.run();
      verts.push(cell.getVertex());
      velAgg+=cell.getVertex().v;
    });
    var velMean=velAgg/cells.length;
    stroke(100*velMean,100,100,0.5-0.25*velMean);
    strokeWeight(0.5+velMean*10);
    noFill();
    beginShape();
    verts.forEach(function(v){
      vertex(v.x, v.y);
    });
    endShape(CLOSE);
  };
}

function Cell(id,x,y, s, d){
  var stiffness=s;
  var decay=d;
  var maxDist=25;
  var repelStiffness=0.01;
  var origin=createVector(x,y);
  var pos=createVector(0,0);
  var vel=createVector(0,0);
  var velMax=maxDist*stiffness;
  var absPos=origin.copy();
  var repel=createVector(0,0);
  var repelMag=maxDist;
  var acc=createVector(0,0);
  var zero=createVector(0,0);
  
  
  this.prevCell=null;
  this.nextCell=null;
  var prevDist=0;
  var nextDist=0;
  var neighbourStiffness=s/10;
  var prevTension=createVector(0,0);
  var nextTension=createVector(0,0);
  
  this.setNextDist=function(){
    nextDist=p5.Vector.sub(absPos, this.nextCell.getPos()).mag();
  };
  
  this.setPrevDist=function(){
    prevDist=p5.Vector.sub(absPos, this.prevCell.getPos()).mag();
  };
  
  this.getPos=function(){
    return absPos;
  }
  
  this.show=function(){
    noStroke();
    push();
    translate(origin.x, origin.y);
    translate(pos.x, pos.y);
    fill(0,100,100,1);
    ellipse(0,0,5);
    pop();
  };
  
  this.repel=function(){
    repel=p5.Vector.sub(absPos,createVector(mouseX, mouseY));
    repelMag=repel.mag();
    if(repelMag<maxDist){
      repel.mult((maxDist-repelMag)*repelStiffness);
    } else {
      repelMag=maxDist;
      repel.mult(0);
    }
  };
  
  this.repelMany=function(){
    repel.mult(0);
    disturbers.forEach(function(d){
      var repelThis=p5.Vector.sub(absPos,createVector(d.x, d.y));
      repelMag=repelThis.mag();
      if(repelMag<maxDist){
        repelThis.mult((maxDist-repelMag)*repelStiffness);
      } else {
        repelMag=maxDist;
        repelThis.mult(0);
      }
      repel.add(repelThis);
    });
  }
  
  this.neighbourTension=function(){
    var prevTarget=p5.Vector.sub(absPos, this.prevCell.getPos());
    prevTarget.setMag(prevDist).add(this.prevCell.getPos());
    prevTension=p5.Vector.sub(prevTarget, absPos);
    var prevDistNow=prevTension.mag();
    // if(id===0) console.log(id+" "+prevDistNow);
    if(prevDistNow>0){
      prevTension.mult(neighbourStiffness);
    } else {
      prevDistNow=0;
      prevTension.mult(0);
    }
    
    var nextTarget=p5.Vector.sub(absPos, this.nextCell.getPos());
    nextTarget.setMag(nextDist).add(this.nextCell.getPos());
    nextTension=p5.Vector.sub(nextTarget, absPos);
    var nextDistNow=nextTension.mag();
    // if(id===0) console.log(id+" "+prevDistNow);
    if(nextDistNow>0){
      nextTension.mult(neighbourStiffness);
    } else {
      nextDistNow=0;
      nextTension.mult(0);
    }
  }
  
  function runPrevTension(){
    
  }
  
 
  this.run=function(){
    acc.add(p5.Vector.sub(zero,pos).mult(stiffness));
    acc.add(repel);
    acc.add(nextTension);
    acc.add(prevTension);
    vel.add(acc);
    vel.mult(decay);
    pos.add(vel);
    acc.mult(0);
    absPos=p5.Vector.add(origin, pos);
  };
  
  this.getVertex=function(){
    return {
      x:absPos.x,
      y:absPos.y,
      v:vel.mag()/velMax
    };
  };
}