Ball Animation

let w;

let h;

let vecLocation = [];

let vecVelocity = [];

const NUM = 100;  //定数

let size = [];

let col = [];

​

function setup() {

  createCanvas(windowWidth, windowHeight);

  frameRate(50);

  w = windowWidth;

  h = windowHeight;

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

    vecLocation[i] = createVector(w/2, h/2);

    vecVelocity[i] = createVector(random(-10, 10), random(-10,10));

    col[i] = color(random(255), random(255), random(255), random(150,255));

    size[i] = random(10,60);

  }

}

​

function draw() {

  background(0);

  noStroke();

  w = windowWidth;

  h = windowHeight;

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

    fill(col[i])

    ellipse(vecLocation[i].x , vecLocation[i].y , size[i], size[i]);

    vecLocation[i].add(vecVelocity[i]);

    if( vecLocation[i].x> w || vecLocation[i].x <0) {

      vecVelocity[i].x= vecVelocity[i].x * -1;

    }

    if( vecLocation[i].y> h || vecLocation[i].y < 0) {

      vecVelocity[i].y = vecVelocity[i].y * -1;

    }

  }

}

​