//why not drop back, finally moves in even velocity?//NEED TO SET ACC, VEL(OTHER WAY THAN TESTING THE NUMBER)//when exceed edge, appear again at the original location. 规律of motion

//set the forceorigin.y to voltage readings, and x goes up gradully// strength of beats. 

//sliders to change vel

//how to embody the quality of dust, randomness

//use nature of code to code the nature

//soil directed dance/performance

​

​

let count=0;

let grid = 3;

let xcount;

let ycount;

let ylevel;

let dustsize = 1;

let radius = 30;

let dust = []; //let dust or let dist=[]?

let oriPos=[];

let forceorigin;

let gravity;

​

​

function setup() {

  createCanvas(400, 400);

  ylevel = height / 5;

  xcount = floor(width / grid);

  ycount = floor(ylevel / grid);

  forceorigin = createVector();

  gravity=createVector(0,0.03);  

​

  //axis direction. gravity >0 to point down

  dust = new Array(xcount * ycount);

  for (let i = 0; i < xcount * ycount; i++) {

    dust[i] = new Particle(

      (i % xcount) * grid,

      height - floor(i / xcount) * grid

    );

   // oriPos[i]=createVector(dust[i].xStart(),dust[i].yStart());

   // oriPos[i]=createVector(dust[i].position.x,dust[i].yStart());

  }

​

}

​

function draw() {

  background(0);

  fill(200, 190, 20);

  noStroke();

  rect(0,height-ylevel,width, ylevel);

​

//   for (let i = 0; i < dust.length; i++) {

//     if (dust[i].isFly(forceorigin) == true) {

//       let forcei=dust[i].setForce();

//       dust[i].applyForce(forcei);

//     }

//     dust[i].update();

//     dust[i].show();

//   }

​

 //for (let i = 0; i < dust.length; i++) {

   // dust[i]

   // oriPos[i]

 //}

​

  for (let dustpar of dust) {

    if (dustpar.isFly(forceorigin) == true) {

      let vel=dustpar.setDire();

      dustpar.applyVel(vel);

      dustpar.applyForce(gravity);

      count=50;

    }

    dustpar.update();

    dustpar.show();

​

  }

  count--;

  if(count==0){

     console.log("hello");

    forceorigin = createVector();

  for (let dustpar of dust) {

    dustpar.goHome(); 

  }

​

  }

//     for(let i=0;i<dust.length;i++){

//  if(dust[i].x<0||dust[i].x>width||dust[i].y<0||dust[i].y>height){

//   dust[i].goHome();

//     }

//     // dust[i].update();

//     // dust[i].show();

//   }

}

​

// function keyPressed() {

//   if (key == ' ') {

//     console.log("hello");

//     forceorigin = createVector();

//   for (let dustpar of dust) {

//     dustpar.goHome(); 

//   }

//   }

// }

​

class Particle {

  constructor(x, y) {

    this.position = createVector(x, y); //dust position

    //let oriX=x;

    //let oriY=y;

    this.origPos = this.position.copy();

    this.velocity = createVector(0,0);

    this.acceleration = createVector(0, 0);

​

    // this.lifespan = 255.0;

  }

  xStart(){

    return this.position.x;

  }

  yStart(){

    return this.position.y;

  }

​

  isFly(forceorigin) {

    let diff = p5.Vector.sub(this.position, forceorigin);

    if (diff.mag() < radius) {

      return true;

    } else {

      return false;

    }

  }

​

  setDire() {

    let dire=p5.Vector.sub(this.position, forceorigin);

    let dis=dire.mag();//how far from the forceorigin?

    let strength=map(dis,0,radius,1.5,0.4); // the shorter the dis, the stronger the force

    dire.normalize();

    dire.mult(strength);

    if(dire.heading()>0){   //if heading down

      dire.mult(-1);        //flip direction

    }

    return dire;

  }

  applyVel(vel){

    this.velocity.add(vel);

}

​

  applyForce(force) {

    this.acceleration.add(force);

  }

  goHome() {

    this.position.x = this.origPos.x;

    this.position.y = this.origPos.y;

    this.velocity.mult(0);

    this.acceleration.mult(0);

  }

​

  update() {

    this.velocity.add(this.acceleration);

    this.position.add(this.velocity);

    //this.acceleration.mult(0);

​

  }

  show() {

    fill(200, 190, 20);

    noStroke();

    square(this.position.x, this.position.y, 1);

    //circle(this.position.x, this.position.y, dustsize);

  }

​

  highlight(){

    fill(100, 190, 20);

    noStroke();

    circle(this.position.x, this.position.y, dustsize*2);

}

  print(){

    // stroke(200);

    // line(100,100,this.velocity.x,this.velocity.y);

    console.log(this.velocity.mag());

    console.log(this.acceleration.mag());

  }

​

stop(){

  if(this.position.x<0||this.position.y>width||this.position.y<0||this.position.y>height){

    this.position.x=x;

    this.position.y=y;

}

​

​

}

  back(){

    this.position.x=xStart();

    this.position.y=yStart();

}

}

//1. update force 2. check affected or not 3. affected particles set their own force 4. move towards the force 5.受力分析

​

function mousePressed() {

  forceorigin.x = mouseX;

  forceorigin.y = mouseY;

​

}

​