game_func.py

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


# reacts to keyboard interaction
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_SPACE:
        fire_bullet(ai_settings, screen, ship, bullets)
    elif event.key == pygame.K_q:
        sys.exit()


# ship's fire
def fire_bullet(ai_settings, screen, ship, bullets):
    if len(bullets) < ai_settings.bullets_allowed:
        new_bullet = Bullet(ai_settings, screen, ship)
        bullets.add(new_bullet)


# checks if keys (left or right) is up and ship should stop moving
def check_keyup_events(event, ship):
    if event.key == pygame.K_RIGHT:
        ship.moving_right = False
    elif event.key == pygame.K_LEFT:
        ship.moving_left = False


# checks which of events is happening
def check_events(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets):
    for event in pygame.event.get():

        if event.type == pygame.QUIT:
            sys.exit()

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

        elif event.type == pygame.KEYUP:
            check_keyup_events(event, ship)

        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)


# start a game by clicking start button
def check_play_button(ai_settings, screen, stats, sb, play_button, ship, aliens, bullets, mouse_x, mouse_y):
        button_clicked = play_button.rect.collidepoint(mouse_x, mouse_y)
        if button_clicked and not stats.game_active:
            ai_settings.initialize_dynamic_settings()
            pygame.mouse.set_visible(False)
            stats.reset_stats()
            stats.game_active = True
            sb.prep_score()
            sb.prep_high_score()
            sb.prep_level()
            sb.prep_ships()
            aliens.empty()
            bullets.empty()

            create_fleet(ai_settings, screen, ship, aliens)
            ship.center_ship()


# displays objects in the game
def upd_screen(ai_settings, screen, stats, sb, ship, aliens, bullets, play_button):
    screen.blit(ai_settings.bg_color, screen.get_rect())
    for bullet in bullets.sprites():
        bullet.draw_bullet()
    ship.blitme()
    aliens.draw(screen)
    sb.show_score()
    if not stats.game_active:
        play_button.draw_button()
    pygame.display.flip()


# check if bullet hit an alien
def check_bullets_aliens_collision(ai_settings, screen, stats, sb, ship, aliens, bullets):
    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_score(stats, sb)
    if len(aliens) == 0:
        bullets.empty()
        ai_settings.increase_speed()
        stats.level += 1
        sb.prep_level()
        create_fleet(ai_settings, screen, ship, aliens)


# removes bullets which are out of the screen
def upd_bullets(ai_settings, screen, stats, sb, ship, aliens, bullets):
    bullets.update()
    for bullet in bullets.copy():
        if bullet.rect.bottom <= 0:
            bullets.remove(bullet)
    check_bullets_aliens_collision(ai_settings, screen, stats, sb, ship, aliens, bullets)


# set the appropriate amount of aliens at the level start (aliens fleet)
def get_number_aliens(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


# creates a single alien of the fleet
def create_alien(ai_settings, screen, aliens, alien_number, row_number):
    alien = Alien(ai_settings, screen)
    alien_width = alien.rect.width
    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 / 2
    aliens.add(alien)


# creates fleet of aliens
def create_fleet(ai_settings, screen, ship, aliens):
    alien = Alien(ai_settings, screen)
    number_aliens_x = get_number_aliens(ai_settings, alien.rect.width)
    number_rows = get_number_rows(ai_settings, ship.rect.height, alien.rect.height)

    for row_number in range(number_rows):
        for alien_number in range(number_aliens_x):
            if row_number == 0:
                row_number += 1
            create_alien(ai_settings, screen, aliens, alien_number, row_number)


# set the appropriate amount of fleet's rows
def get_number_rows(ai_settings, ship_height, alien_height):
    available_space_y = (ai_settings.screen_height - (3*alien_height) - ship_height)
    number_rows = int(available_space_y/(1.5 * alien_height))
    return number_rows


# controls the display of aliens fleet
def update_aliens(ai_settings, stats, screen, sb, ship, aliens, bullets):
    check_fleet_edges(ai_settings, aliens)
    aliens.update()
    if pygame.sprite.spritecollideany(ship, aliens):
        ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)
    check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets)


# checks if fleet hits the edges
def check_fleet_edges(ai_settings, aliens):
    for alien in aliens.sprites():
        if alien.check_edges():
            change_fleet_direction(ai_settings, aliens)
            break


# change the direction of fleet when it hits the edges
def change_fleet_direction(ai_settings, aliens):
    for alien in aliens.sprites():
        alien.rect.y += ai_settings.fleet_drop_speed
    ai_settings.fleet_direction *= -1


# checks if your ship is hit by an enemy and if you have any lives left
def ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets):
    if stats.ships_left > 0:
        stats.ships_left -= 1
        sb.prep_ships()
        aliens.empty()
        bullets.empty()

        create_fleet(ai_settings, screen, ship, aliens)
        ship.center_ship()

        sleep(0.5)

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


# checks if fleet hit the bottom of the screen
def check_aliens_bottom(ai_settings, stats, screen, sb, ship, aliens, bullets):
    screen_rect = screen.get_rect()
    for alien in aliens.sprites():
        if alien.rect.bottom >= screen_rect.bottom:
            ship_hit(ai_settings, stats, screen, sb, ship, aliens, bullets)
            break


# updating high score
def check_high_score(stats, sb):
    if stats.score > stats.high_score:
        stats.high_score = stats.score
        sb.prep_high_score()