[Processing] particle/interaction project

import processing.video.*;
 
int stat;
int btn = 0;
int btn2 = 0;
int btn3 = 0;
float nbsum = 0;
float pbsum = 0;
float nbsum2 = 0;
float pbsum2 = 0;
float nbsum3 = 0;
float pbsum3 = 0;
 
ParticleSystem ps;
Capture video;
PImage img, dback;
double sum4;
 
void setup() {
  size(600, 480);
  video = new Capture(this, 640, 480, 30);
  video.start();
 
  img = createImage(640, 480, RGB);
  dback = createImage(640, 480, GRAY);
  background(0);
  
  ps = new ParticleSystem(new PVector(width/2, -1500));
}
 
 
void draw() {
  if(video.available()){
    video.read();
  }
 
  video.loadPixels();
  img.loadPixels();
  for(int x = 50; x < 630; x++){
    for(int y = 0; y < 480; y++){
      img.pixels[y*img.width +(640-x)] = video.pixels[y*img.width + x];
    }
  }
  img.filter(GRAY);
  checkInterection2();
  dithering();
  checkInterection();
  if(btn == 1){
    ps.addParticle();
    ps.run();
  }
  
  image(img, 0, 480);
  //rect(300, 0, 20, 20);
}
 
void checkInterection(){
  img.loadPixels();
  nbsum = 0;
  for(int dx = 0; dx < 20; dx++){
    for(int dy = 0; dy < 20; dy++){
      nbsum = nbsum + brightness(img.pixels[(dy)*img.width + (500+dx)]);
    }
  }
 
  if(abs(nbsum - pbsum) > 6000){
    if(btn == 0){btn = 1;}
    else if(btn == 1){btn = 0;}
  }
  //text("brightness difference : " + abs(nbsum - pbsum), 10, 480);
  
  pbsum = nbsum;
}
 
void checkInterection2(){
  img.loadPixels();
  nbsum2 = 0;
  for(int dx = 0; dx < 20; dx++){
    for(int dy = 0; dy < 20; dy++){
      nbsum2 = nbsum2 + brightness(img.pixels[(dy)*img.width + (100+dx)]);
    }
  }
  
  if(abs(nbsum2 - pbsum2) > 10000){
    if(btn2 == 0){if(btn3==1){btn2 = 2;}else{btn2 = 1;}}
    else if(btn2 == 1){btn2 = 2;}
    else if(btn2 == 2){btn2 = 3;}
    else if(btn2 == 3){btn2 = 4;}
    else if(btn2 == 4){btn2 = 0;}
  }
  //text("brightness difference : " + abs(nbsum2 - pbsum2), 10, 480);
  
  pbsum2 = nbsum2;
}
 
void backbtn(){
  img.loadPixels();
  nbsum3 = 0;
  for(int dx = 0; dx < 20; dx++){
    for(int dy = 0; dy < 20; dy++){
      nbsum3 = nbsum3 + brightness(img.pixels[(dy)*img.width + (500+dx)]);
    }
  }
  
  if(abs(nbsum3 - pbsum3) > 10000){
    if(btn3 == 0){btn3 = 1;}
    else if(btn3 == 1){btn3 = 2;}
    else if(btn3 == 2){btn3 = 3;}
    else if(btn3 == 3){btn3 = 4;}
    else if(btn3 == 4){btn3 = 0;}
  }
  text("brightness difference : " + abs(nbsum3 - pbsum3), 10, 480);
  
  pbsum3 = nbsum3;
}
 
 
void dithering(){
  stat = 1;
  
  img.loadPixels();
  if(btn2 == 0){background(0);}
  else if(btn2 == 1){background(#25DBD6);}
  else if(btn2 == 2){background(#0130F7);}
  else if(btn2 == 3){background(#C03A1A);}
  else if(btn2 == 4){background(#8A3C86);}
  for(int x = 5; x < 635; x+=10){
    for(int y = 5; y < 475; y+=10){
      sum4 = 0;
      for(int a = -5; a<5; a++){
        for(int b = -5; b<5; b++){
          sum4 = sum4 + brightness(img.pixels[(y+b)*img.width + (x+a)]);
        }
      }     
 
      if (sum4 > 25000){
        ellipse(x, y, 10, 10);
        noStroke();
      }else if ((20000<sum4)&&(sum4<25000)){
        ellipse(x, y, 8, 8);
        noStroke();
      }else if ((15000<sum4)&&(sum4<20000)){
        ellipse(x, y, 6, 6);
        noStroke();
      }else if ((10000<sum4)&&(sum4<15000)){
        ellipse(x, y, 4, 4);
        noStroke();
      }else if ((5000<sum4)&&(sum4<10000)){
        ellipse(x, y, 2, 2);
        noStroke();
      }
      if(btn2 == 0){
        int crand = int(random(1,4));
        if (crand == 1){fill(#DA2429);}
        else if (crand == 2){fill(#FECF08);}
        else if (crand == 3){fill(#3FC5E5);}
        else if (crand == 4){fill(#75C379);}
      }
      else if(btn2 == 1){fill(#DA2429);}
      else if(btn2 == 2){fill(#FECF08);}
      else if(btn2 == 3){fill(#3FC5E5);}
      else if(btn2 == 4){fill(#75C379);}
    }
  }
}
 
 
class ParticleSystem {
  ArrayList<Particle> particles;
  PVector origin;
 
  ParticleSystem(PVector position) {
    origin = position.copy();
    particles = new ArrayList<Particle>();
  }
 
  void addParticle() {
    particles.add(new Particle(origin));
  }
 
  void run() {
    for (int i = particles.size()-1; i >= 0; i--) {
      Particle p = particles.get(i);
      p.run();
      if (p.isDead()) {
        particles.remove(i);
      }
    }
  }
}
 
class Particle {
  PVector position;
  PVector velocity;
  PVector acceleration;
  float lifespan;
 
  Particle(PVector l) {
    acceleration = new PVector(0, 0.05);
    velocity = new PVector(random(-1, 1), random(-2, 0));
    position = l.copy();
    lifespan = 255.0;
  }
 
  void run() {
    update();
    display();
  }
 
  void update() {
    velocity.add(acceleration);
    position.add(velocity);
    lifespan -= 0.4;
  }
 
  void display() {
    //stroke(255, lifespan);
    noStroke();
    int crand = int(random(1,4));
    if (crand == 1){fill(#DA2429, lifespan);}
    else if (crand == 2){fill(#FECF08, lifespan);}
    else if (crand == 3){fill(#3FC5E5, lifespan);}
    else if (crand == 4){fill(#75C379, lifespan);}
    //fill(#854845, lifespan); //change color
    int rands = int(random(8,20));
    ellipse(position.x, position.y, rands, rands);
  }
 
  boolean isDead() {
    if (lifespan < 0.0) {
      return true;
    } else {
      return false;
    }
  }
}

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