class MainScreen(arcade.Window):
'''
Main application class.
'''
def __init__(self, width, height, title):
super().__init__(width, height, title)
arcade.set_background_color(arcade.color.WHITE_SMOKE)
def setup(self):
'''
Setting up the environment.
'''
# Setting up space.
self.space = pymunk.Space()
self.space.gravity = GRAVITY
self.space.sleep_time_threshold = 1
# Creating cars.
self.cars = []
for _ in range(NUM_CARS):
self.cars.append(BoxCar(self.space))
# Setting up terrain and checkpoints.
self.terrain = Terrain(self.space)
self.checkpoints = self.terrain.get_checkpoints()
# Setting up extra UI elements.
self.goal = arcade.create_line(self.checkpoints[-1].x - 40,
self.checkpoints[-1].y,
self.checkpoints[-1].x - 40,
self.checkpoints[-1].y + 50,
arcade.color.GREEN, 2)
self.generation_number = 1
self.best_score = 0
self.plot_history = []
self.score_history = []
self.score_list = arcade.ShapeElementList()
def on_draw(self):
'''
Render the screen.
'''
arcade.start_render()
self.goal.draw()
self.show_status()
self.terrain.draw()
for car in self.cars:
car.draw()
def on_update(self, delta_time):
'''
Update the simulation.
'''
self.space.step(DT)
# To check if all cars in the current generation are alive.
all_dead = True
for car in self.cars:
alive = car.update_lifespan(self.checkpoints)
if alive:
all_dead = False
if self.best_score < car.get_checkpoint_index():
self.best_score = car.get_checkpoint_index()
if all_dead:
self.new_generation()
def new_generation(self):
'''
Generate a new generation of cars.
'''
gene_scores = []
for car in self.cars:
g_s = car.get_chromosome_and_score()
gene_scores.append(g_s)
new_genes = evolve(gene_scores)
constraints = self.space.constraints
for c in constraints:
self.space.remove(c)
for car in self.cars:
self.space.remove(car.chassis.body, car.chassis.shape)
for wheel in car.wheels:
self.space.remove(wheel.body, wheel.shape)
self.cars = []
for gene in new_genes:
self.cars.append(BoxCar(self.space, gene))
self.plot_history.append(self.best_score)
plt.clf()
plt.plot(self.plot_history)
plt.xlabel('Number of Generations')
plt.ylabel('Best Score per Generation')
plt.draw()
plt.show(block=False)
self.score_history.append({
'gen': self.generation_number,
'score': self.best_score
})
self.score_history = sorted(self.score_history,
key=lambda x: x['score'],
reverse=True)[:25]
self.best_score = 0
self.generation_number += 1
def show_status(self):
'''
Show the current generation and history stats.
'''
score = f"Current Generation: {self.generation_number}\nBest Car Info | Score: {self.best_score}"
arcade.draw_text(score, 50, 50, arcade.color.RED, anchor_y='top')
arcade.draw_text('Top 25 Scores',
1100,
780,
arcade.color.DARK_BLUE,
anchor_x='center',
anchor_y='top')
for i, score in enumerate(self.score_history):
arcade.draw_text(
f"Generation: {score['gen']} | Score: {score['score']}\n",
1120,
760 - i * 30,
arcade.color.DARK_ELECTRIC_BLUE,
anchor_x='center',
anchor_y='top')
