Hi all
This is my first step towards a Boid code. I wrote this code to learn PVector, vector manipulation and OOP (Class). This sketch creates a system with two elements (balls) that try to catch up to the mouse pointer. These elements bounce off the walls and have different accelerations. Red ball's acceleration is twice that of the blue ball. Both have a maximum speed limitation. Both balls start at random locations. The user can assign the acceleration and color of the balls while creating the Object. I have placed as many comments as time allowed (it is Friday past midnight).

Next step would be to make these elements interact with each other while chasing the target which would make it a Boid code.

Took help from PVector and Objects tutorial here @ processing.org
Have fun with the code and the animation. Feel free to comment.

Bye,
pf

Code

1. // Declare Objects
   Boid Boid1;
   Boid Boid2;
   
   void setup() {
     size(500,500);
     background(2);
     Boid1 = new Boid(new PVector(random(width),random(height)), new PVector(0,0), 1.0, color(255,0,0));
     Boid2 = new Boid(new PVector(random(width),random(height)), new PVector(0,0), 0.5, color(0,0,255));
   }
   
   void draw() {
     noStroke();
     fill(255,10);
     rect(0,0,width,height);
     Boid1.move();
     Boid1.display();
     Boid2.move();
     Boid2.display();
   }
   
   class Boid {
     PVector pos;
     PVector vel;
     float acc;
     color colour;
     float maxspeed;
     PVector accelerate;
    
   Boid(PVector position, PVector velocity, float acceleration, color paint) {
     pos = position;
     vel = velocity;
     acc = acceleration;
     maxspeed = 10;
     colour = paint;
   }
   
   void move() {
   // Determine Mouse location 
     PVector mouse = new PVector(mouseX,mouseY);
   // Determine which direction to go (accelerate) 
     PVector direction = PVector.sub(mouse,pos);
   // Determine how close to target
     float separation = direction.mag();
     direction.normalize(); // Normalize to get unit vector
     direction.mult(acc); // Calculate actual acceleration
     accelerate = direction;
   
     vel.add(accelerate); // Calculate velocity
     vel.limit(maxspeed); // Limit speed
    
     if (separation < 20) { // If Boid close to target then stop
       vel.x = 0;
       vel.y = 0;
     }
    
     pos.add(vel); // Calculate position
    
     // Limit movement within window and bounce at window edge
     if ((pos.x < 0) || (pos.x > width)) {
       vel.x = vel.x * -1;
     }
     if ((pos.y < 0) || (pos.y > height)) {
       vel.y = vel.y * -1;
     } 
   }
   
   void display() {
     stroke(0);
     fill(colour);
     ellipse(pos.x,pos.y,10,10);
   }
   }