Game_Functions.py

import sys
import pygame
from Bullet import Bullet
from Alien import Alien
from time import sleep


def check_Events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
    # Respond to keypresses and mouse events:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()
        elif event.type == pygame.KEYUP:
            check_key_up_events(event, ship)

        elif event.type == pygame.KEYDOWN:
            check_keydown_events(event, ai_settings, screen, ship, bullets)

        elif event.type == pygame.MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y)


def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y):
    # Start a new game when the player when the player clicks play
    button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
    if button_clicked and not stats.game_active:
        # Reset the game settings
        ai_settings.initialize_dynamic_settings()

        # Hide the mouse cursor
        pygame.mouse.set_visible(False)
        # Reset the game statistics
        stats.reset_stats()
        stats.game_active = True

        # Reset the scoreboard images
        sb.prep_score()
        sb.prep_high_score()
        sb.prep_level()
        sb.prep_ships()

        # Empty the list of aliens and bullets
        aliens.empty()
        bullets.empty()

        # Create a new fleet and center the ship
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

    else:
        stats.game_active = False
        pygame.mouse.set_visible(True)


def check_keydown_events(event, ai_settings, screen, ship, bullets):
    if event.key == pygame.K_RIGHT:
        ship.moving_right = True

    elif event.key == pygame.K_LEFT:
        ship.moving_left = True

    elif event.key == pygame.K_UP:
        ship.moving_up = True

    elif event.key == pygame.K_DOWN:
        ship.moving_down = True

    elif event.key == pygame.K_SPACE:
        # Create a new bullet and add it to a the bullets group
        fire_bullet(ai_settings, screen, ship, bullets)

    elif event.key == pygame.K_q:
        sys.exit()


def check_key_up_events(event, ship):
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False

    elif event.key == pygame.K_LEFT:
        ship.moving_left = False

    elif event.key == pygame.K_UP:
        ship.moving_up = False

    elif event.key == pygame.K_DOWN:
        ship.moving_down = False


def update_Screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):
    # Redraw the screen during each pass through the loop
    screen.fill(ai_settings.bg_color)

    #  Redraw all bullets behind ship and aliens
    for bullet in bullets.sprites():
        bullet.draw_bullet()

    ship.blitme()

    aliens.draw(screen)

    # Draw the score
    sb.show_score()

    # Draw the play button if the game is inactive
    if not stats.game_active:
        play_button.draw_button()

    # Make the most recent screen visible
    pygame.display.flip()


def update_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    bullets.update()

    # Get rid of old bullets out of the screen
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)

    check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens, bullets)


def check_bullet_alien_collisions(ai_settings, screen, stats, sb, ship, aliens, bullets):
    # Check for any bullets that have hit aliens
    # If so, get rid of the bullet and the alien
    # The sprite.groupcollide function returns a dictionary where keys are bullets and values are aliens
    collisions = pygame.sprite.groupcollide(bullets, aliens, True, True)

    if collisions:
        for aliens in collisions.values():
            stats.score += ai_settings.alien_points * len(aliens)
            sb.prep_score()
        check_high_scores(stats, sb)

    # Repopulate the fleet of aliens
    if len(aliens) == 0:
        # Destroy existing bullets, speedup the game and create new fleet
        bullets.empty()
        ai_settings.increase_speed()

        # If the entire fleet is destroyed, start a new level
        stats.level += 1
        sb.prep_level()

        create_fleet(ai_settings, screen, ship, aliens)


def fire_bullet(ai_settings, screen, ship, bullets):
    if len(bullets) < ai_settings.number_bullets_allowed:
        # Create a new bullet and add it to a the bullets group
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)


def get_number_aliens_x(ai_settings, alien_width):
    available_space_x = ai_settings.screen_width - 2 * alien_width
    number_aliens_x = int(available_space_x / (2 * alien_width))
    return number_aliens_x


def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    # Create an alien and place it in a row
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    alien.x = alien_width + 2 * alien_width * alien_number
    alien.rect.left = alien.x
    alien.rect.top = alien.rect.height + 2 * alien.rect.height * row_number
    aliens.add(alien)


def get_number_rows(ai_settings, ship_height, alien_height):
    # Determine the number of rows of aliens  that fit on the screen
    available_space_y = (ai_settings.screen_height - 3 * alien_height - ship_height)
    number_rows = int(available_space_y / (2 * alien_height))

    return number_rows


def create_fleet(ai_settings, screen, ship, aliens):
    # Create a full fleet of aliens
    # Create an alien and find the number of aliens in a row
    # Spacing between the aliens is one alien width
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    number_aliens_x = get_number_aliens_x(ai_settings, alien_width)
    number_rows = get_number_rows(ai_settings, ship.rect.height, alien.rect.height)

    # Create the first row of aliens
    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            # Create an alien and place it in the row
            create_alien(ai_settings, screen, aliens, alien_number, row_number)


def ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets):
    # Respond to ship being hit by an alien

    if stats.ships_left > 0:
        # Decrement ships left
        stats.ships_left -= 1

        # Update the scoreboard
        sb.prep_ships()

        # Empty the list of aliens and bullets
        aliens.empty()
        bullets.empty()

        # Create a new fleet and center the ship
        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

        # Pause
        sleep(0.5)

    else:
        stats.game_active = False


def update_aliens(ai_settings, stats, screen, sb, ship, aliens, bullets):
    # Check if the fleet is at an edge and then update the positions of all aliens in the fleet
    check_fleet_edges(ai_settings, aliens)
    aliens.update()

    # Look for any ship-alien collisions:
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)

    # Look for aliens hitting the bottom of the screen:
    check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets)


def check_fleet_edges(ai_settings, aliens):
    # Respond appropriately if any aliens have reached an edge
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break


def change_fleet_direction(ai_settings, aliens):
    # Drop the entire fleet and change the fleet's direction
    for alien in aliens.sprites():
        alien.rect.top += ai_settings.fleet_drop_speed

    ai_settings.fleet_direction *= -1


def check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets):
    # Check if any aliens have reached the bottom of the screen
    screen_rect = screen.get_rect()

    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            # Treat this the same as if the ship got hit
            ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)
            break


def check_high_scores(stats, sb):
    # Check to see if there is a new high score
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()