simpleswarmer2.pde

/**
* Simple Swarmer 2
*
*/

int numAttractors = 256;
int numMasses = 8192*2;
float maxSpeed = 4.0f;
float maxAccel = 1.0f;

Attractor[] a = new Attractor[numAttractors];
PointMass[] pts = new PointMass[numMasses];

void setup() {
  size(1280, 720); 
  frameRate(60);
  for ( int i=0; i<numAttractors; i++) {
    a[i] = new Attractor();
  }
  for ( int i=0; i<numMasses; i++) {
    pts[i] = new PointMass();
  }
}
void update() {
  for ( int i=0; i<numAttractors; i++) {
    a[i].update();
  }
  for ( int i=0; i<numMasses; i++) {
    pts[i].update(a);
  }
}
void draw() {
  
  update();
  smooth();
   background(212);
   //fill(255,212,192,16);
   //rect(0,0,width,height);
  for ( int i=0; i<numAttractors; i++) {
    a[i].draw();
  }
  for ( int i=0; i<numMasses; i++) {
    pts[i].draw(a);
  }

  fill(0);
  text(frameRate + "fps", 10, 10, 100, 30);
}



class Point {
  float x, y;
  Point() {
  }
  Point(float _x, float _y) {
    x = _x;
    y = _y;
  }
  float getAngle(){
   return atan2(y,x); 
  }
  void setMax(float _m){
    float f = dist(x,y,0,0);
    if(abs(f) > _m){
       float scale = _m/abs(f);
       x *= scale;
       y *= scale;
    }
  }
};

class PointMass {
  color c;
  Point pos;
  Point vel;
  Point acc;
  PointMass() {
    c = color(random(64)+64,random(64)+64,random(64)+64);
    pos = new Point(random(width-10f) + 5.0f, random(height-10.0f) + 5.0f);
    vel = new Point(random(4.0f) - 2.0f, random(4.0f) - 2.0f);
    acc = new Point(0, 0);
  }
  void update(Attractor[] a) {
    
    for (int i=0; i<a.length; i++) {
      float d = dist(pos.x, pos.y, a[i].pos.x, a[i].pos.y);
      if (d<100) {
        // float angle = atan2(a[i].pos.y - pos.y, a[i].pos.x, a[i].pos.x - pos.x); // not needed
        acc.x += (a[i].pos.x - pos.x)*(2.0f/(d*d));
        acc.y += (a[i].pos.y - pos.y)*(2.0f/(d*d)); 
      }
    }
    
    
    acc.setMax(4.0f);
    //acc.x = max(min(acc.x,1),-1);
    //acc.y = max(min(acc.y,1),-1);
    


    
    vel.x *= 0.95f;
    vel.y *= 0.95f;
    
    
    vel.x += acc.x;
    vel.y += acc.y;
    
   //vel.x = max(min(vel.x,2),-2);
   // vel.y = max(min(vel.y,2),-2);
    vel.setMax(1.0f);
    
    
    pos.x += vel.x;
    pos.y += vel.y;

    // check for bounce
    if (pos.x >width || pos.x < 0) {
      pos.x -= 2*vel.x;
      vel.x *= -1.0f;
    }
    if (pos.y > height || pos.y < 0) {
      pos.y -= 2*vel.y;
      vel.y *= -1.0f;
    }
    
    
    
    
  }
  void draw(Attractor[] a) {
/*
    for (int i=0; i<a.length; i++) {
      float d = dist(pos.x, pos.y, a[i].pos.x, a[i].pos.y);
      if (d<100) {
        noFill();
        stroke(0);
        line(a[i].pos.x, a[i].pos.y, pos.x, pos.y);
      }
    }
*/
//    fill(0,0,0,64);
    stroke(c);
    noFill();
//    ellipse(pos.x, pos.y, 2, 2);
  //  rect(pos.x,pos.y,1,1);
point(pos.x,pos.y);  
}
};


void keyPressed(){
 setup(); 
}

class Attractor {
  Point pos;
  Point vel;
  Attractor() {
    pos = new Point(random(width-10f) + 5.0f, random(height-10.0f) + 5.0f);
    vel = new Point(random(6.0f) - 3.0f, random(6.0f) - 3.0f);
  }
  void update() {
    pos.x += vel.x;
    pos.y += vel.y;

    // check for bounce
    if (pos.x >width || pos.x < 0) {
      pos.x -= 2*vel.x;
      vel.x *= -1.0f;
    }
    if (pos.y > height || pos.y < 0) {
      pos.y -= 2*vel.y;
      vel.y *= -1.0f;
    }
  }
  void draw() {
    stroke(255);
noFill();
 //   rect(pos.x,pos.y,1,1);
    point(pos.x,pos.y);
//    ellipse(pos.x, pos.y, 3, 3);
  }
};