Grid Display Processing

BaseParticleWithVector.pde

class BaseParticleWithVector implements BaseParticleWithVectorInterface {
  PVector location;
  PVector velocity;

  float scalarVelocity;
  float r;
  
  BaseParticleWithVector() {
    location = new PVector(random(width), random(height));
    velocity = new PVector(0, 0);

    scalarVelocity = 0;
    r = 5;
  }

  void render() {
    fill(255);
    noStroke();
    
    ellipse(location.x,location.y,r,r);
  }

  void walk() {
    //override in subclass
  }
}

interface BaseParticleWithVectorInterface {
  void walk();
}

Grid.pde

//可変長配列
ArrayList<Particle> particles;
int cols = 10;
int rows = 10;
int cellWidth = 0;
int cellHeight = 0;

void setup() {
  //スクリーンの大きさはディスプレイに合わせる
  size(displayWidth, displayHeight);

  cellWidth = width / cols;
  cellHeight = cellWidth;
  // cellHeight = height / rows;

  //パーティクルの数
  int particlesSize = cols * rows;

  particles = new ArrayList<Particle>();

  for (int i = 0; i < cols; i++) {
    for (int j = 0; j < rows; j++) {
      Particle u = new Particle(cellWidth * i + cellWidth / 2, cellHeight * j + cellHeight / 2);
      particles.add(u);
    }
  }

  rectMode(CENTER);
  background(0);
}

void draw() {
  fill(0);
  rect(0, 0, width, height);

  //ArrayListのfor文の省略記法
  for (Particle u : particles) {
    u.walk();
    u.render();
  }
  
  //フレームのキャプチャ保存
  // saveFrame("frames/######.tif");
}

Particle.pde

class Particle extends BaseParticleWithVector {
  float angle;
  float startAngle;
  PVector center;
  
  Particle(int centerX, int centerY) {
    location = new PVector(centerX, centerY);

    angle = 0;

    //位相のズレ
    startAngle = random(PI * 2);

    //画面の中心
    center = new PVector(width / 2, height / 2);

    //スカラー量の速度
    scalarVelocity = 1;

    velocity.x = random(-scalarVelocity, scalarVelocity);
    velocity.y = random(-scalarVelocity, scalarVelocity);
  }

  void render() {
    fill(210,252,254,255);
    noStroke();

    ellipse(location.x,location.y,r,r);
  }

  void walk() {

    // location.x += velocity.x;
    // location.y += velocity.y;


    //画面外に出た時の処理
    if(location.x < 0 || location.x > width) {
      velocity.x *= -1;
    } else if(location.y < 0 || location.y > height) {
      velocity.y *= -1;
    }
  }
}