let pincher;

​

// spring variables

let particles = [];

let springs = [];

let anchors = [];

let grabbed = {Left: null, Right:null};

​

let spacing = 1;

let k = 0.08;

let grabDist = 40;

let numParticels = 80;

let anchorNum = 16;

let gravity;

​

​

//handpose variables

let video;

​

let W = 640;

let H = 480;

​

function preload() {

  pincher = new PinchTracker(ml5, W, H);

}

​

function setup() {

  createCanvas(W, H);

  angleMode(DEGREES);

  //handpose setup

  video = createCapture(VIDEO);

  video.size(640, 480);

  video.hide();

  pincher.setup(video);

  //spring setup

  gravity = createVector(0,-0.01);

  // create all particles

  for (let i=0; i < numParticels; i++){

    // random position

    let nx = 100 + random(width-100);

    let ny = 100 + random(height-100);

    createParticle(i, nx, ny);

  }

}

​

​

function draw() {

  background(208,226,192);

  // Handpose draw

  translate(width, 0);

  scale(-1, 1);

  tint(255,50);

  // image(video, 0, 0, width, height);

  // connect pinches to anchors

  connectPinchToAnchor("Left");

  connectPinchToAnchor("Right");

  // springs

  for (let s=0; s<springs.length; s++){

    springs[s].update();

​

    let positive = map(s, 0, springs.length, 0, 255);

    let negative = map(s, 0,springs.length , 255, 0);

    springs[s].show(positive, negative);

  }

​

  // particles

  for (let p=0; p < particles.length; p++){

    particles[p].applyForce(gravity);

    particles[p].update();

    let negative = map(p, 0, particles.length, 255, 0);

    particles[p].show(negative, p);

  }

}

​

function createParticle(i, x, y){

  // instantiate a new particle with position

  particles.push(new Particle(x, y));

  // is it a regular particle?

  if (i!=0){

    let a = particles[i];

    let b = particles[floor(random(1, i-1))];

    let spring = new Spring(k, spacing, a, b);

    springs.push(spring);

  }

​

  // is it an anchor?

  // for first, last and every n particles

  if( i == 0  ||  i == numParticels-1 || i%anchorNum == 0){

    anchors.push(particles[i]);

    particles[i].locked = true;

  }

}

​

function connectPinchToAnchor(side){

  let pinches = pincher.getPinches();

  // pinches.Left || Right >> {x: 0, y: 0} || null

  // grabbed.Left || Right >> anchor || null

  //   Left || Right

  //   pinch    grabbed  

  // ------------------

  //     Y   |    Y

  //     N   |    Y

  //     Y   |    N

  //     N   |    N

  if(pinches[side] === null){

    // if still grabbing -> release particle 

    if(grabbed[side] !== null){

      grabbed[side].influencer = null;

      grabbed[side] = null;

    }

  }else{

    // has pinch

    if(grabbed[side] === null){  

      // go find a particle to grab 

      grabbed[side] = findClosestAnchor(pinches[side]);

      if(grabbed[side] !== null){

        // turn on influencing

        grabbed[side].influencer = pinches[side];

      }

    }else{

      // update grabbed position with pinch position 

      if(grabbed[side].influencer !== null){

        grabbed[side].influencer.x = pinches[side].x;

        grabbed[side].influencer.y = pinches[side].y;    

      }

    }

  }

}

​

​

// find the anchor particle that is closest to the pinch.

// if not close enough just return null

function findClosestAnchor(pinch){

  if(pinch === null){

    // no pinch :(

    return null;

  }

  let closest;

  let minD = 1000;

  // go over the anchors

  for (let p of anchors){

    let d = dist(pinch.x, pinch.y, p.position.x, p. position.y);  

    if(d < minD){

      closest = p;

      minD = d;

    }

  }

  // found a match - return it

  if( minD  < grabDist){

    return closest;

  }

  // no match :(

  return null;

}

​

​

​