12-3
import pygame
class Ship():
def __init__(self, ai_settings, screen):
''' Initialize the ship and set its starting position.'''
self.screen=screen
self.ai_settings = ai_settings
# Load the ship image and get its rect.
self.image = pygame.image.load('images/ship.bmp')
self.rect = self.image.get_rect()
self.screen_rect = screen.get_rect()
# Start each new ship at the bottom center of the screen.
self.rect.centerx = self.screen_rect.centerx
self.rect.centery = self.screen_rect.centery
# Store a decimal value for the ship's center.
self.centerx = float(self.rect.centerx)
self.centery = float(self.rect.centery)
# Movement flags
self.moving_right = False
self.moving_left = False
self.moving_up = False
self.moving_down = False
def update(self):
''' Update the ship's position based on the movement flags.'''
# Update the ship's center value, not the rect.
if self.moving_right and self.rect.right < self.screen_rect.right:
self.centerx += self.ai_settings.ship_speed_factor
if self.moving_left and self.rect.left > 0:
self.centerx -= self.ai_settings.ship_speed_factor
if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
self.centery += self.ai_settings.ship_speed_factor
if self.moving_up and self.rect.top > 0:
self.centery -= self.ai_settings.ship_speed_factor
# Update rect object from self.center.
self.rect.centerx = self.centerx
self.rect.centery = self.centery
def blitme(self):
''' Draw the ship at its current location.'''
self.screen.blit(self.image, self.rect)
