Hi I am playign around with the script below, btu I am trying to change the starting positions so they don't all start from the centre-----does anyone know how??? Thanks
int initBoidNum = 200; //amount of boids to start the program with
BoidList flock1,flock2;
void setup()
{
size(600,600,P2D);
//create and fill the list of boids
flock1 = new BoidList(initBoidNum,0);
//flock2 = new BoidList(100,255);
}
void draw()
{
//clear screen
background(205);
flock1.run();
//flock2.run();
//smooth();
//print framerate
//println(frameRate);
}
class Boid
{
//fields
PVector pos,vel,acc,ali,coh,sep; //pos, velocity, and acceleration in a vector datatype
float neighborhoodRadius; //radius in which it looks for fellow boids
float maxSpeed = 1; //maximum magnitude for the velocity vector
float maxSteerForce = .05; //maximum magnitude of the steering vector
float sMod,aMod,cMod; //modifiers for the three forces on the boid
float h; //hue
//constructors
Boid(PVector inPos)
{
pos = new PVector();
pos.set(inPos);
vel = new PVector(random(-1,1),random(-1,1));
acc = new PVector(0,0);
neighborhoodRadius = 30;
sMod = 1; aMod = 1; cMod = 4;
}
Boid(PVector inPos,PVector inVel,float r)
{
pos = new PVector();
pos.set(inPos);
vel = new PVector();
vel.set(inVel);
acc = new PVector(0,0);
neighborhoodRadius = r;
}
void run(ArrayList bl)
{
acc.add(avoid(new PVector(mouseX,mouseY),true));
ali = alignment(bl);
coh = cohesion(bl);
sep = seperation(bl);
if(PVector.dist(new PVector(mouseX,mouseY),pos)>100)
{
acc.add(PVector.mult(ali,aMod));
acc.add(PVector.mult(coh,cMod));
acc.add(PVector.mult(sep,sMod));
}
if(PVector.dist(new PVector(mouseX,mouseY),pos)<50)
maxSpeed = 2;
else
maxSpeed = 1;
move();
checkBounds();
render();
}
void move()
{
vel.add(acc); //add acceleration to velocity
vel.limit(maxSpeed); //make sure the velocity vector magnitude does not exceed maxSpeed
pos.add(vel); //add velocity to position
acc.mult(0); //reset acceleration
}
void checkBounds()
{
if(pos.x>width) pos.x=0;
if(pos.x<0) pos.x=width;
if(pos.y>height) pos.y=0;
if(pos.y<0) pos.y=height;
}
void render()
{
pushMatrix();
translate(pos.x,pos.y);
rotate(atan2(vel.y,vel.x)); //rotate drawing matrix to direction of velocity
stroke(0);
noFill();
//ellipse(0,0,neighborhoodRadius*2,neighborhoodRadius*2);
noStroke();
fill(h);
//draw triangle
beginShape(TRIANGLES);
vertex(3,0);
vertex(-3,2);
vertex(-3,-2);
endShape();
popMatrix();
}
//steering. If arrival==true, the boid slows to meet the target. Credit to Craig Reynolds
PVector steer(PVector target,boolean arrival)
{
PVector steer = new PVector(); //creates vector for steering
if(!arrival)
{
steer.set(PVector.sub(target,pos)); //steering vector points towards target (switch target and pos for avoiding)
steer.limit(maxSteerForce); //limits the steering force to maxSteerForce
}
else
{
PVector targetOffset = PVector.sub(target,pos);
float distance=targetOffset.mag();
float rampedSpeed = maxSpeed*(distance/100);
float clippedSpeed = min(rampedSpeed,maxSpeed);
PVector desiredVelocity = PVector.mult(targetOffset,(clippedSpeed/distance));
steer.set(PVector.sub(desiredVelocity,vel));
}
return steer;
}
//avoid. If weight == true avoidance vector is larger the closer the boid is to the target
PVector avoid(PVector target,boolean weight)
{
PVector steer = new PVector(); //creates vector for steering
steer.set(PVector.sub(pos,target)); //steering vector points away from target
if(weight)
steer.mult(1/sq(PVector.dist(pos,target)));
//steer.limit(maxSteerForce); //limits the steering force to maxSteerForce
return steer;
}
PVector seperation(ArrayList boids)
{
PVector posSum = new PVector(0,0);
PVector repulse;
for(int i=0;i<boids.size();i++)
{
Boid b = (Boid)boids.get(i);
float d = PVector.dist(pos,b.pos);
if(d>0&&d<=neighborhoodRadius)
{
repulse = PVector.sub(pos,b.pos);
repulse.normalize();
repulse.div(d);
posSum.add(repulse);
}
}
return posSum;
}
PVector alignment(ArrayList boids)
{
PVector velSum = new PVector(0,0);
int count = 0;
for(int i=0;i<boids.size();i++)
{
Boid b = (Boid)boids.get(i);
float d = PVector.dist(pos,b.pos);
if(d>0&&d<=neighborhoodRadius)
{
velSum.add(b.vel);
count++;
}
}
if(count>0)
{
velSum.div((float)count);
velSum.limit(maxSteerForce);
}
return velSum;
}
PVector cohesion(ArrayList boids)
{
PVector posSum = new PVector(0,0);
PVector steer = new PVector(0,0);
int count = 0;
for(int i=0;i<boids.size();i++)
{
Boid b = (Boid)boids.get(i);
float d = dist(pos.x,pos.y,b.pos.x,b.pos.y);
if(d>0&&d<=neighborhoodRadius)
{
posSum.add(b.pos);
count++;
}
}
if(count>0)
{
posSum.div((float)count);
}
steer = PVector.sub(posSum,pos);
steer.limit(maxSteerForce);
return steer;
}
}
class BoidList
{
ArrayList boids; //will hold the boids in this BoidList
float h; //for color
BoidList(int n,float ih)
{
boids = new ArrayList();
h = ih;
for(int i=0;i<n;i++)
boids.add(new Boid(new PVector(width/2,height/2)));
}
void add()
{
boids.add(new Boid(new PVector(width/2,height/2)));
}
void addBoid(Boid b)
{
boids.add(b);
}
void run()
{
for(int i=0;i<boids.size();i++) //iterate through the list of boids
{
Boid tempBoid = (Boid)boids.get(i); //create a temporary boid to process and make it the current boid in the list
tempBoid.h = h;
tempBoid.run(boids); //tell the temporary boid to execute its run method
}
}
}
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