Gravity (프로세싱=Processing)

ElectricShock 2017. 1. 5. 00:36

// 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);

}