// A Mover and an Attractor
Mover m;
Attractor a;
void setup() {
size(640,360);
m = new Mover();
a = new Attractor();
}
void draw() {
background(255);
// Apply the attraction force from the Attractor on the Mover.
PVector force = a.attract(m);
m.applyForce(force);
m.update();
a.display();
m.display();
}
class Attractor {
float mass;
PVector location;
float G;
Attractor() {
location = new PVector(width/2,height/2);
mass = 20;
G = 0.4;
}
PVector attract(Mover m) {
PVector force = PVector.sub(location,m.location);
float distance = force.mag();
// Remember, we need to constrain the distance
// so that our circle doesn’t spin out of control.
distance = constrain(distance,5.0,25.0);
force.normalize();
float strength = (G * mass * m.mass) / (distance * distance);
force.mult(strength);
return force;
}
void display() {
stroke(0);
fill(175,200);
ellipse(location.x,location.y,mass*2,mass*2);
}
}
프로세싱 홍대.zip
