class AlienInvasion:
"""Overall class to manage game assets and behavior."""
def __init__(self):
"""Initialize the game, and game resources."""
pygame.init()
self.settings = Settings(
) # import Settings into the main program file
self.screen = pygame.display.set_mode(
(0, 0), pygame.FULLSCREEN
) # passig a wiondow size of 0,0 to FULLSCREEN tells Pygame to figure out window size to fill screen
self.settings.screen_width = self.screen.get_rect().width
self.settings.screen_height = self.screen.get_rect(
).height # creates a display window, will draw the game's graphical elements
pygame.display.set_caption(
"Alien Invasion"
) # tuple that defines dimensions by referencing the attributes in self.settings
# Create an instance to store game statistics.
self.stats = GameStats(self)
# and create a scoreboard
self.sb = Scoreboard(self)
self.ship = Ship(
self
) # the self arg refers to the current instance of AlienInvasion
# Parameter gives Ship access to the game's resources, such as screen object
self.bullets = pygame.sprite.Group(
) # We use this group to draw bullets to the screen on each pass through...
# ...the main loop and to update each bullet's position.
self.aliens = pygame.sprite.Group()
self._create_fleet()
self.sounds = Sounds(self)
self.bullet = Bullet(self)
# Make the Play button
self.play_button = Button(
self, "Play"
) # Creates an instance of Button w/ label PLAY, but will call draw_button in _update_screen.
def run_game(self):
"""Start the main loop for the game."""
while True:
self._check_events()
if self.stats.game_active:
self.ship.update(
) # function in ship.py, updates position of ship image
self._update_bullets()
self._update_aliens()
self._update_screen()
def _check_events(
self
): # "Helper Method" Does work inside a class but isn't meant to be called through an instance
"""Respond to keypresses and mouse events""" # def run_game calls this method (easier to keep code clean and clear)
keystate = pygame.key.get_pressed()
if keystate[
pygame.
K_SPACE]: # if spacebar is pressed (and helf down) we call _fire_bullet()
self._fire_bullet()
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN: # Pygame responds if it detects a KEYDOWN event
self._check_keydown_events(event)
elif event.type == pygame.KEYUP: # else if player releases the right arrow, we set moving_right back to false
self._check_keyup_events(event)
elif event.type == pygame.MOUSEBUTTONDOWN: # Pygame detects a mousebuttondown event when player clicks anywhere on screen
mouse_pos = pygame.mouse.get_pos(
) # We use mouse.get_pos() which returns a tuple w/ the mouse cursor's x/y coord when clicked
self._check_play_button(
mouse_pos
) # We send those values to the new method _check_play_button
def _check_play_button(self, mouse_pos):
"""Start a new game when the player clicks Play."""
button_clicked = self.play_button.rect.collidepoint(
mouse_pos
) # If mouse_pos overlaps the play_button area and MOUSEBUTTON DOWN detected, True or False.
if button_clicked and not self.stats.game_active: # Game will restart if Play is clicked AND the game is not currently active
self._start_game()
def _start_game(self):
"""Starts game..."""
# Reset the game settings.
self.settings.initialize_dynamic_settings()
# Reset the game statistics.
self.stats.reset_stats()
self.stats.game_active = True
self.sb.prep_score(
) # We call prep_score() after resetting game stats when starting new game. This sets scoreboard to 0.
self.sb.prep_level()
self.sb.prep_ships()
# Get rid of any remaining aliens and bullets.
self.aliens.empty()
self.bullets.empty()
# Create a new fleet and center the ship.
self._create_fleet()
self.ship.center_ship()
# Hide the mouse cursor
pygame.mouse.set_visible(
False) # When game is active we make the cursor invisible
# Start music when game starts
self._update_sounds()
def _update_sounds(self):
"""Update sound effects"""
self.sounds.play_bg_music()
def _check_keydown_events(self, event):
"""Respond to keypresses"""
if event.key == pygame.K_RIGHT: # if R arrow pressed we set moving right to True
self.ship.moving_right = True
elif event.key == pygame.K_LEFT: # if L arrow pressed we set moving left to True
self.ship.moving_left = True
elif event.key == pygame.K_UP: # if UP arrow pressed we set moving up to True
self.ship.moving_up = True
elif event.key == pygame.K_DOWN: # if DOWN arrow pressed we set moving down to True
self.ship.moving_down = True
elif event.key == pygame.K_p:
self._start_game()
def _check_keyup_events(self, event):
"""Respnd to key releases."""
if event.key == pygame.K_RIGHT: # (otherwise it would be left true and ship would continue moving R after keydown event)
self.ship.moving_right = False
elif event.key == pygame.K_LEFT:
self.ship.moving_left = False
elif event.key == pygame.K_UP:
self.ship.moving_up = False
elif event.key == pygame.K_DOWN:
self.ship.moving_down = False
elif event.key == pygame.K_q: # if Q is pressed, game quits.
sys.exit()
def _fire_bullet(self):
"""Create a new bullet and add it to the bullets group"""
now = pygame.time.get_ticks()
if now - self.bullet.last_shot > self.bullet.shoot_delay:
self.bullet.last_shot = now
new_bullet = Bullet(
self) # ...make an instance of Bullet and call it new_bullet
self.bullets.add(
new_bullet
) # we then add it to the group BULLETS using the add() method (similar to append() for Pygame)
self.sounds.play_bullet_sound()
def _update_bullets(self):
"""Update position of bullets and get rid of old bullets."""
# Update bullet positions.
self.bullets.update(
) # the group auto calls update() for each sprite in the group
# Get rid of bullets that have disappeared
for bullet in self.bullets.copy():
if bullet.rect.bottom <= 0:
self.bullets.remove(bullet)
self._check_bullet_alien_collisions()
def _check_bullet_alien_collisions(self):
"""Respond to bullet-alien collisions."""
# Remove any bullets and aliens that have collided
collisions = pygame.sprite.groupcollide( #compares the position of all bulets in self.bullets and all the aliens in self.aliens
self.bullets, self.aliens, True, True
) # if overlap, collide() adds a key-value pair to the dic it returns, removes bullets and aliens
if collisions: # Pygame returns a collisions dictionary if True
for aliens in collisions.values(
): # now we loop through the collisions dictionary
self.stats.score += self.settings.alien_points * len(
aliens
) # We increase stats.score by alien_point value, and multiply it by the amount of aliens if more than one
self.sb.prep_score(
) # we call prep_score()to create a new image for updated score
self.sb.check_high_score(
) # after updating score, we call check_high_score to update high score if needed.
self.sounds.play_collision_sound()
if not self.aliens: # we check if alien group is empty
# Destroy existing bullets and create new fleet.
self.bullets.empty(
) # if alien group empty, we remove existing bullets by using empty() method
self._create_fleet(
) # We then call _create_fleet(), which fills the screen with aliens again
self.settings.increase_speed() # And increase the pace of the game
# Increase level.
self.stats.level += 1
self.sb.prep_level()
def _update_aliens(self):
"""Chk if the fleet is at an edge,
then update the position of all aliens in the fleet."""
self._check_fleet_edges()
self.aliens.update()
# Look for alien-ship collisions.
if pygame.sprite.spritecollideany(
self.ship, self.aliens
): # spritecollideany() functions takes 2 args, sprite and a group.
self._ship_hit(
) # if spritecollideany() returns None, if block doesn't execute
# Look for aliens hitting the bottom of the screen.
self._check_aliens_bottom()
def _check_fleet_edges(self):
"""Respond appropriately if any aliensw have reached an edge."""
for alien in self.aliens.sprites(
): # if check_edges() returns true we know an alien is at edge and direction needs to change
if alien.check_edges():
self._change_fleet_direction(
) # ...so we call _change_fleet_direction()
break
def _change_fleet_direction(self):
"""Drop the entire fleet and change the fleet's direction."""
for alien in self.aliens.sprites():
alien.rect.y += self.settings.fleet_drop_speed
self.settings.fleet_direction *= -1 # after fleet has dropped, we change the value of fleet_direction by multiplying its current value by -1
def _create_fleet(self):
"""Create the fleet of aliens."""
# Create an alien and find the number of aliens in a row.
# Spacing between each alien is equal to one alien width.
alien = Alien(self) # we create 1 alien to get width and height
alien_width, alien_height = alien.rect.size # size contains a tuple with the width and height of a rect object
available_space_x = self.settings.screen_width - (
2 * alien_width
) # we calculate x space available for aliens and # of aliens that can fit
number_aliens_x = available_space_x // (2 * alien_width)
# Create the number of rows of aliens that fit on screen.
ship_height = self.ship.rect.height
available_space_y = (self.settings.screen_height - (3 * alien_height) -
ship_height)
number_rows = available_space_y // (3 * alien_height)
# Create the full fleet of aliens.
for row_number in range(number_rows):
for alien_number in range(
number_aliens_x
): # create loop that counts from 0 to # of aliens calculated above
# Create an alien and place it in the row.
self._create_alien(alien_number, row_number)
self.ship.center_ship()
def _create_alien(self, alien_number, row_number):
"""Create an alien and place it in the row."""
alien = Alien(self) # create alien
alien_width, alien_height = alien.rect.size
alien.x = alien_width + 2 * alien_width * alien_number
alien.rect.x = alien.x # We use the alien's x attribute to se the position of its rect
alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
self.aliens.add(
alien
) # we create an alien, then add that alien to the alien sprite Group() that will hold the fleet
def _update_screen(self):
"""Update images on the screen and flip to the new screen.""" # Redraw the screen during each pass through the loop.
# re-scale background image
self.scaled_bg_image = pygame.transform.scale(
self.settings.bg_image,
(self.screen.get_rect().width, self.screen.get_rect().height))
# draw re-scaled image to screen using blit() method
self.screen.blit(self.scaled_bg_image, [0, 0])
self.ship.blitme(
) # we draw the ship on the screen by calling ship.blitme()
for bullet in self.bullets.sprites(
): # .sprites() method returns a list of all sprites in the group bullets
bullet.draw_bullet(
) # to draw all fired bullets, we loop though the sprites in bullets and call draw_bullet on each
# draws each element in group at the position defined by its rect attribute
self.aliens.draw(
self.screen
) # the draw() method requires one arg: a surface on which to draw
# Draw the score information.
self.sb.show_score()
# Draw the play button if the game is inactive.
if not self.stats.game_active:
self.play_button.draw_button()
pygame.display.flip() # Make the most recently drawn screen visible.
def _ship_hit(self):
"""Respond to the ship being hit by an alien"""
if self.stats.ships_left > 0:
# Decrement ships_left and update scoreboard.
self.stats.ships_left -= 1
self.sb.prep_ships()
# Get rid of any remaining aliens and bullets.
self.aliens.empty()
self.bullets.empty()
# Create a new fleet and center the ship.
self._create_fleet()
self.ship.center_ship()
# Pause.
sleep(0.5)
else:
self.stats.game_active = False
pygame.mouse.set_visible(True) # make mouse cursor visible again.
def _check_aliens_bottom(self):
"""Check if any aliens have reached the bottom of the screen."""
screen_rect = self.screen.get_rect()
for alien in self.aliens.sprites():
if alien.rect.bottom >= screen_rect.bottom:
# Treat this the same as if the ship got hit.
self._ship_hit()
break
class AlienInvasion:
def __init__(self):
## initialize game
pygame.init()
self.settings = Settings()
self.screen = pygame.display.set_mode(
(self.settings.screen_width, self.settings.screen_height))
pygame.display.set_caption("Alien Invasion")
self.stars = pygame.sprite.Group()
self._create_sky()
self.stats = GameStats(self)
self.sb = Scoreboard(self)
self.ship = Ship(self)
self.bullets = pygame.sprite.Group()
self.aliens = pygame.sprite.Group()
self.snd = Sounds()
self.snd.start_bg_music()
self._create_fleet()
self.play_button = Button(self, "Play")
def run_game(self):
## main loop for game
while True:
self._check_events()
if self.stats.game_active:
self.ship.update()
self._update_bullets()
self._update_aliens()
self._update_screen()
def _check_events(self):
## responds to keypresses and mouse events
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
elif event.type == pygame.KEYDOWN:
self._check_keydown_events(event)
elif event.type == pygame.KEYUP:
self._check_keyup_events(event)
elif event.type == pygame.MOUSEBUTTONDOWN:
mouse_pos = pygame.mouse.get_pos()
self._check_play_button(mouse_pos)
def _check_play_button(self, mouse_pos):
button_clicked = self.play_button.rect.collidepoint(mouse_pos)
if button_clicked and not self.stats.game_active:
self.snd.play_start_sound()
self.settings.initialize_dynamic_settings()
self.stats.reset_stats()
self.stats.game_active = True
self.sb.prep_score()
self.sb.prep_level()
self.sb.prep_ships()
self.aliens.empty()
self.bullets.empty()
self._create_fleet()
self.ship.center_ship()
pygame.mouse.set_visible(False)
def _check_keydown_events(self, event):
## respond to key presses
if event.key == pygame.K_RIGHT:
## move ship to the right
self.ship.moving_right = True
elif event.key == pygame.K_LEFT:
self.ship.moving_left = True
elif event.key == pygame.K_q:
sys.exit()
elif event.key == pygame.K_SPACE:
self._fire_bullet()
def _ship_hit(self):
if self.stats.ships_left > 0:
self.snd.play_lost_ship_sound()
self.stats.ships_left -= 1
self.sb.prep_ships()
self.aliens.empty()
self.bullets.empty()
self._create_fleet()
self.ship.center_ship()
sleep(0.5)
else:
self.snd.play_game_over_sound()
self.stats.game_active = False
pygame.mouse.set_visible(True)
def _check_keyup_events(self, event):
if event.key == pygame.K_RIGHT:
self.ship.moving_right = False
elif event.key == pygame.K_LEFT:
self.ship.moving_left = False
def _fire_bullet(self):
## create a new bullet and add it to group
if len(self.bullets) < self.settings.bullets_allowed:
new_bullet = Bullet(self)
self.bullets.add(new_bullet)
self.snd.play_bullet_sound()
def _update_bullets(self):
## update bullet positions
self.bullets.update()
## get rid of bullets off screen
for bullet in self.bullets.copy():
if bullet.rect.bottom <= 0:
self.bullets.remove(bullet)
self._check_bullet_alien_collisions()
def _check_bullet_alien_collisions(self):
collisions = pygame.sprite.groupcollide(self.bullets, self.aliens,
True, True)
if collisions:
self.snd.play_hit_sound()
for aliens in collisions.values():
self.stats.score += self.settings.alien_points
self.sb.prep_score()
self.sb.check_high_score()
if not self.aliens:
self.bullets.empty()
self._create_fleet()
self.settings.increase_speed()
self.stats.level += 1
self.sb.prep_level()
def _check_aliens_bottom(self):
screen_rect = self.screen.get_rect()
for alien in self.aliens.sprites():
if alien.rect.bottom >= screen_rect.bottom:
self._ship_hit()
break
def _create_sky(self):
for s in range(self.settings.NUMBER_STARS):
self._create_star()
def _create_star(self):
star = Star(self)
x_loc = r(0, self.settings.screen_width)
y_loc = r(0, self.settings.screen_height)
star.rect.x = x_loc
star.rect.y = y_loc
self.stars.add(star)
def _create_fleet(self):
## make an alien
alien = Alien(self)
## determine how many aliens can fit on a row
alien_width, alien_height = alien.rect.size
available_space_x = self.settings.screen_width - (2 * alien_width)
number_alien_x = available_space_x // (2 * alien_width)
## determine number of rows that fit on a screen
ship_height = self.ship.rect.height
available_space_y = (self.settings.screen_height - (3 * alien_height) -
ship_height)
number_rows = available_space_y // (2 * alien_height)
## create full fleet of aliens
for row_number in range(number_rows):
for alien_number in range(number_alien_x):
self._create_alien(alien_number, row_number)
def _create_alien(self, alien_number, row_number):
alien = Alien(self)
alien_width, alien_height = alien.rect.size
alien.x = alien_width + 2 * alien_width * alien_number
alien.rect.x = alien.x
alien.rect.y = alien.rect.height + 2 * alien.rect.height * row_number
self.aliens.add(alien)
def _update_aliens(self):
self._check_fleet_edges()
self.aliens.update()
## look for alien-ship collisions
if pygame.sprite.spritecollideany(self.ship, self.aliens):
self._ship_hit()
## look for aliens hitting bottom of screen
self._check_aliens_bottom()
def _check_fleet_edges(self):
for alien in self.aliens.sprites():
if alien.check_edges():
self._change_fleet_direction()
break
def _change_fleet_direction(self):
for alien in self.aliens.sprites():
alien.rect.y += self.settings.fleet_drop_speed
self.settings.fleet_direction *= -1
def _update_screen(self):
## update images on the screen
## redraw screen during each pass through loop
self.screen.fill(self.settings.bg_color)
self.stars.draw(self.screen)
self.ship.blitme()
for bullet in self.bullets.sprites():
bullet.draw_bullet()
self.aliens.draw(self.screen)
self.sb.show_score()
if not self.stats.game_active:
self.play_button.draw_button()
## make recently drawn screen visible
pygame.display.flip()
