hello, in the following program each agent moves randomly in the screen until it collide with other agent, when that happens it change its color. For this i made a simple function that calculates the distance between all the agents in an array. When the distance is less than some number then "something happens".it works fine but  my question is how about if i need that something happens just when an agent collide with 2 agents?

I need that each agent  moves randomly  until it collides with 2 other agents at the same time, so i need that each agent collide with 2 other agents to trigger a function. How can i make that each agent can be aware of how many agents are colliding with them?





int numAgente= 12;
Agente[] arreglo =new Agente[numAgente];

void setup(){
size(800,700);
smooth();
noStroke();
background(238, 282, 299);
for (int i=0; i<numAgente; i++){

arreglo[i] = new Agente();
}
}


void draw(){

background(238, 282, 299);
 
for (int k=0; k<numAgente; k++){

arreglo[k].dibuja();
}
}

class Agente{
float x= random(800);
float y= random (700 );
float dista;
 color coloryo ;
 
void dibuja(){
x = x + random(20) - 10;
y = y + random(20) - 10;

//fill(24, 88,99, 34);
//ellipse(x, y , 180, 180);
fill(coloryo);
ellipse(x , y ,180,180);

for (int i=0; i<numAgente; i++){

for (int j= i+1 ; j <numAgente; j++){
 if ( i !=  j){
dista = sqrt (((arreglo[i].x - arreglo[j].x) * (arreglo[i].x - arreglo[j].x) )+  ((arreglo[i].y - arreglo[j].y) * (arreglo[i].y - arreglo[j].y)));
 if (dista < 180){

   arreglo[i].coloryo =  color(222, 40, 0);
   arreglo[j].coloryo =  color(222, 40, 0);

}
else
{
coloryo =  color(2, 40, 0);

}
}
}
}

}
}

antiplastik wrote on Dec 29^th, 2008, 10:02pm:

Well, I think it is OK (but the i != j test is redundant), it is a way to avoid testing an agent against itself, and to avoid doing tests twice: if an agent collides another, no need to do the reverse test.
But the trick doesn't scale well for multiple tests...

That's the reason why I haven't answered initially: the optimization is binary, checking pairs of objects. Maybe you can extend it to three objects, but not to an arbitrary number.
Funnily, I just answered collision detection help which has a similar concern. Maybe it can help.

BTW: you can use dist() function. It does the same thing as the sqrt but it is slightly more readable...

Here is what I got while trying to keep your base code:
Code:

int numAgente= 42;
 
Agente[] arreglo = new Agente[numAgente];
 
void setup(){
  size(800,700);
  smooth();
  noStroke();
  background(238, 282, 299);
  for (int i=0; i<numAgente; i++){
    arreglo[i] = new Agente(i);
  }
}
 
void draw(){
  background(238, 282, 299);
  for (int k=0; k<numAgente; k++){
    arreglo[k].mueve();
  }
  for (int k=0; k<numAgente; k++){
    arreglo[k].check();
  }
  for (int k=0; k<numAgente; k++){
    arreglo[k].dibuja();
  }
}
 
class Agente{
float x = random(800);
float y = random(700);
float moviemiento = random(20) - 10;
float moviemientodos = random(20) - 10;
color coloryo;
int rank;

Agente(int i) { rank = i; }
   
void mueve(){
  // x = x + movimiento;
  x = x + random(20) - 10;
  y = y +  random(20) - 10 ;
}

void check(){
  int collisionCount = 0;  
  for (int i=0; i<numAgente; i++){
    if ( i != rank){
      float dista = dist(arreglo[i].x, arreglo[i].y, x, y);
      if (dista < 60){
        collisionCount++;  
      }
    }
  }
  if (collisionCount >= 2) {
    coloryo = color(222, 40, 0);
  } else if (collisionCount == 1) {
    coloryo = color(222, 240, 0);
  } else {
    coloryo = color(2, 40, 0);
  }
}
   
void dibuja(){
  fill(24, 88,99, 54);
  ellipse(x, y , 60, 60);
  fill(coloryo);
  ellipse(x , y ,15,15);
}
} 
 

PhiLho one question, is it posible to adapt you code in a way each agent can percieve the state or a variable  of the 2 colliding agents?  For example if each agent have a new variable like this :

float stateA =  random(10) ;

how can an agent percieve the value of each each that collides with it? I ask you because in your code you just have one iteration and before i made a code that can percieve neighbours variables but it uses nested iteration like this:
 for(int i=0;i <bichos.length;i++){
 for(int j=0;j<bichos.length;j++){
 float dx=bichos[i].x-bichos[j].x;
 float dy=bichos[i].y-bichos[j].y;
    if((i!=j)&&(sqrt(dx*dx+dy*dy)<rb)){
        bichos[i].colorea(bichos[j].rr);

 }

 }

 }

Any idea?

hello, philho. I can make that each agent perceives the state of each agent that collides it, that works fine.  But what i need is that each agent can percieve the state of the "2" agents (just when it collides with 2) that collides it and add them.  Perceiving the state of one agent that collides is not problem , but how can i make something like this: each agent moves randomly when 2 agents collide one agent , the agent can percieve the state of both agents and then add them . if the sum of both agents that are colliding me is more than "whatever" something happens.
Any idea?


int numAgente= 12;

Agente[] arreglo = new Agente[numAgente];

void setup(){
 size(800,700);
 smooth();
 noStroke();
 // print( random (5));
 background(238, 282, 299);
 for (int i=0; i<numAgente; i++){
   arreglo[i] = new Agente(i);
 }
}

void draw(){

 background(38, 82, 29);
 for (int k=0; k<numAgente; k++){
   arreglo[k].mueve();
 }
 for (int k=0; k<numAgente; k++){
   arreglo[k].check();
 }
 for (int k=0; k<numAgente; k++){
   arreglo[k].dibuja();
 }
}

 
class Agente{
float x = random(800);
float y = random(700);

float stateA = random (5);
float stateB = random (5);

color coloryo;
int rank;

Agente(int i) { rank = i; }
   
void mueve(){
 // x = x + movimiento;
 x = x + random(20) - 10;
 y = y +  random(20) - 10 ;
}



void check(){
 int collisionCount = 0;  
 for (int i=0; i<numAgente; i++){
   if ( i != rank){
     float dista = dist(arreglo[i].x, arreglo[i].y, x, y);
     if (dista < 60){
       collisionCount++;  
   //    print(arreglo[i].stateA + "--");
 //here it checks if the  state of each agent that collides is more than 3
 //if so, then it adds 1 to my state,
// but i need to check the state of the colliding agent just when i collide with 2 at the same time  and then sum both
// if the sum of both agents that are colliding me is more than 4 , then something happens, how can i do this?
   if (arreglo[i].stateA > 3) {
     
     stateA = stateA + 1;
   }
     }
   }
 }
 if (collisionCount >= 2) {
   coloryo = color(222, 40, 0);
   
   
   
 } else if (collisionCount == 1) {
   coloryo = color(222, 240, 0);
 } else {
   coloryo = color(2, 40, 0);
 }
}
   
void dibuja(){
 fill(24, 88,99, 54);
 ellipse(x, y , 60, 60);
 fill(coloryo);
 ellipse(x , y ,15,15);
}
}