chain_reaction.pyde

from random import choice

atoms = []  # lista de objetos
neutrons = []

def setup():
    """ Define área de desenho e popula lista de particles """
    size(800, 800)  # área de desenho (width, height)
    half_width, half_height = width / 2, height / 2
    density = 200   # try 900   
    for _ in range(density):
        new_atom = Particle(random(width),random(height))
        atoms.append(new_atom)

def draw():
    """ Limpa a tela, plot e atualiza particles """
    background(0)  # atualização do desenho, fundo preto
    for atom in reversed(atoms):
        atom.plot()
        atom.update()

    for neutron in neutrons:
        neutron.plot()
        neutron.update()


def mousePressed():  # click to add neutrons
    neutrons.append( Particle(mouseX, mouseY, neutron=True))


class Particle():
    """ Classe Particle, cor sorteada, velocidade sorteada """
    def __init__(self, px, py, psiz=None, neutron=False):
        self.x = px
        self.y = py
        if psiz:
            self.siz = psiz
        else:
            self.siz = random(5, 10)
        self.vx = random(-0.1,0.1) if not neutron else random(10, 15) * choice((-1, 1)) 
        self.vy = random(-0.1,0.1) if not neutron else random(10, 15) * choice((-1, 1))
        self.neutron = neutron
        if neutron:
            self.cor = color(255)
            self.siz = 3
        else:
            self.cor = color(random(256),  # R
                         random(256),  # G
                         random(256),  # B
                         200)  

    def plot(self):
        """ Desenha círculo """
        fill(self.cor)
        circle(self.x, self.y, self.siz)


    def update(self):
        """ atualiza a posição do objeto e devolve do lado oposto se sair """
        self.x += self.vx
        self.y += self.vy
        if self.neutron:
            for other in reversed(atoms):
                if dist(self.x, self.y, other.x, other.y) < 3:
                    atoms.remove(other)
                    neutrons.append( Particle(self.x, self.y, neutron=True))
                    neutrons.append( Particle(self.x, self.y, neutron=True))
                    fill(255)
                    circle(self.x, self.y, 100)
            return
        h = self.siz / 2
        if self.x > width + h:
            self.x = -h
        if self.y > height + h:
            self.y = -h
        if self.x < -h:
            self.x = width + h
        if self.y < -h:
            self.y = height + h