Project: Smart Ships Part 2

import pygame, sys, numpy, random
from pygame.locals import *

pygame.init()

FPS = 100 # controls how fast each frame goes
fpsClock = pygame.time.Clock()

# set up the window
DISPLAYSURF = pygame.display.set_mode((500, 500))
pygame.display.set_caption('Ship')

# basic setup
WHITE = (255, 255, 255)
shipImg = pygame.image.load('ship.gif')
depot = pygame.image.load('depot.gif')

fontObj = pygame.font.Font('freesansbold.ttf', 15)

class DNA:
    """genotype for the ships"""
    def __init__(self):
        self.genes = [numpy.array([0])]*lifetime # creates a vector for every "frame"
        for i in range(lifetime):
            self.genes[i] = numpy.array([random.randint(-1, 1),
            random.randint(-1,1)])

class Ship:
    """A ship"""
    def __init__(self):
        self.location = numpy.array([0,400]) # initial location at bottom left
        self.velocity = numpy.array([0,0]) # not moving
        self.acceleration = numpy.array([0,0]) # not accelerating
        self.dna = DNA() # each ship has a genotype
        self.ontarget = False 

    def applyForce(self, f):
        self.acceleration += f 

    def update(self):
        self.velocity += self.acceleration # so that velocity adds up
        self.location += self.velocity
        self.acceleration *= 0 # resets the acceleration

    def fitness(self):
        d = numpy.linalg.norm(self.location-numpy.array([247, 96]))
        self.fitness = (1/d) # the smaller the distance, the greater the fitness

    def crossover(self, partner): # creates a child from two parents
        child = Ship()
        midpoint = random.randint(0, len(self.dna.genes))
        for i in range(len(self.dna.genes)):
            if i >= midpoint:
                child.dna.genes[i] = self.dna.genes[i]
            else:
                child.dna.genes[i] = partner.dna.genes[i]
        return child

    def mutate(self): # mutates the genes randomly
        for i in range(len(self.dna.genes)):
            if random.random() < mutationrate:
                self.dna.genes[i] = numpy.array([random.randint(-1, 1),
                random.randint(-1,1)])

lifetime = 50 # how many frames there are, per cycle
lifecounter = 0
cyclecounter = 0

# location of depot
depotx = 200
depoty = 0

population_no = 50 # number of ships
mutationrate = 0.01 # rate of mutation of genes

population = []
for _ in range(population_no): # creates an array of Ships
    population.append(Ship())

def cycle():
    for i in population: # calculates fitness for all population
        i.fitness()

    mating_pool = []
    for i in population:
        n = int(i.fitness * 1000)
        for x in range(n): # adds Ships into mating pool based on fitness
            mating_pool.append(i)

    for i in range(len(population)):
        a = random.randint(0, len(mating_pool)-1)
        b = random.randint(0, len(mating_pool)-1)

        parent_a = mating_pool[a]
        parent_b = mating_pool[b]

        child = parent_a.crossover(parent_b) # creates child based on fitness

        child.mutate()
        population[i] = child # replaces the parent with the child

while True: # the main loop
    DISPLAYSURF.fill(WHITE)
    DISPLAYSURF.blit(depot, (depotx, depoty))
    pygame.draw.rect(DISPLAYSURF, (0,0,0), (depotx, depoty, 96, 96,),1)

    textSurfaceObj = fontObj.render("Cycle: " + str(cyclecounter), True, (0,0,0))
    textRectObj = textSurfaceObj.get_rect()
    textRectObj.bottomright = (500, 500)

    DISPLAYSURF.blit(textSurfaceObj, textRectObj)

    if lifecounter < lifetime:
        for s in population:
            # if any ship is in rectangle, then it's on target and stops moving
            if ((s.location[0] > depotx-32 and s.location[0] < depotx+96-32) and
            (s.location[1] > depoty and s.location[1] < depoty+80)):
                s.ontarget = True

            #if not, then the ships keep accelerating per frame
            if s.ontarget != True:
                s.applyForce(s.dna.genes[lifecounter])
                s.update()
                DISPLAYSURF.blit(shipImg, s.location)
            else:
                DISPLAYSURF.blit(shipImg, s.location)
        lifecounter += 1

    else:
        lifecounter = 0
        cyclecounter += 1
        cycle()

    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()

    pygame.display.update()
    fpsClock.tick(FPS)