particle [] p = new particle [500];
void setup(){
for(int i = 0; i<500; i++){
p[i] = new particle(random(400),random(400),random(10));
}
size (400,400);
}
void loop(){
if (!mousePressed){background (255);}
for(int i = 0; i<500; i++){
p[i].cmove();
p[i].gmove2();
noStroke();
fill(i/10+130,i/10+110,i/10,i/10+100);
ellipse(p[i].x-5,p[i].y-5,p[i].m+1,p[i].m+1);
}
}
class particle{
float x,y,m,xv,yv;
particle (float x, float y, float m){
this.x = x;
this.y = y;
this.m = m;
xv = 0.0;
yv = 0.0;
}
void cmove(){
float angle = atan2(y-mouseY,x-mouseX)+(PI/2);
x += cos(angle)*(abs(xv)+abs(yv));
y += sin(angle)*(abs(xv)+abs(yv));
}
void gmove2(){
float mouseMass = 5;
  float distX = mouseX - x;
  float distY = mouseY - y;
  float dist = sqrt(sq(distX) + sq(distY));
  if (dist < 5){
  dist = 5;
  }
  float grav = (m * mouseMass) / sq(dist) * 5;
  float xGrav = grav * (distX/dist);
  float yGrav = grav * (distY/dist);
  float xAccel = xGrav / m;
  float yAccel = yGrav / m;
  xv += xAccel;
  yv += yAccel;
  x +=xv;
  y +=yv;
}
}