如何使用 Python 的 Pygame 庫更改 class 中的參數值

Question

我正在嘗試寫一個像游戲一樣的太空入侵者。 我最初編寫我的代碼只提供 1 個入侵者來給我一些可以構建的東西。 當我開始添加更多入侵者時，我決定創建一個 class，在其中我可以讓入侵者列表循環。

我試圖在我的列表中的一個方法中更改入侵者的 x 坐標，但我發現它並沒有改變值，因此入侵者留在原地。 任何幫助將不勝感激！

這是我正在研究的 class：

import sys, pygame, random
from pygame.locals import *
import itertools
#from bullet import Invader

pygame.init()
screen_height = 600
screen_width = 1200
DISPLAYSURF = pygame.display.set_mode((screen_width, screen_height))
FPS = 200

score = 0

pygame.display.set_caption('Testing Pygame')
spaceship = pygame.image.load('spaceship copy.bmp')

spaceship_rect = spaceship.get_rect()
DISPLAYSURF_rect = DISPLAYSURF.get_rect()

FONT = pygame.font.Font('freesansbold.ttf', 32)
text = FONT.render('Score ' + str(score), True, (180, 180, 180))
text_rect = text.get_rect()
text_rect.centerx = DISPLAYSURF_rect.centerx
text_rect.centery = DISPLAYSURF_rect.centery

invader_right_movement = False
invader_left_movement = True

class Invader():

    def __init__(self, invader, invader_x, invader_y):
        self.invader = invader
        self.rect = invader.get_rect()
        self.rect.x = invader_x
        self.rect.y = invader_y

    def move_invader(self, movement):
        #self.x = self.rect.x
        #self.y = self.rect.y
        #Move invader
        if invader_right_movement == True:
            self.rect.x += movement
        if invader_left_movement == True:
            self.rect.x -= movement
        DISPLAYSURF.blit(self.invader, (self.rect.x, self.rect.y))

invaders_x = [10, 90, 170, 250, 330, 410, 490, 570, 650, 730]
invaders_y = 40

invader_image = pygame.image.load('invader.bmp')
invaders = []
for x in invaders_x:
    invaders.append(Invader(invader_image,x,invaders_y)) 

invaders_rect = []
for invader, x in zip(invaders, invaders_x):
    invader.centerx = x
    invader.centery = invaders_y


spaceship_rect.centerx = DISPLAYSURF_rect.centerx
spaceship_rect.centery = DISPLAYSURF_rect.bottom - 40

move_right = False
move_left = False
move_rate = 5

bullet_firing = False

#Testing bullet firing
RED = (240, 0, 0)
x = spaceship_rect.centerx - 3
y = spaceship_rect.top
width = 6
height = 24
#bullet = pygame.draw.rect(DISPLAYSURF, RED, (x, y, width, height))
#bullet.centerx = spaceship_rect.centerx - 3
#bullet.centery = spaceship_rect.top + height
#bullet_rect = pygame.draw.rect(DISPLAYSURF, RED, (x, y, width, height))
bullets_fired = []
bullet_fired = False

while True:
    DISPLAYSURF.fill((0, 0, 0))
    DISPLAYSURF.blit(spaceship, spaceship_rect)
    DISPLAYSURF.blit(text, text_rect)


    #get invader to move 1-8 pixels randomly to one side before turning back
    num_movements = random.randint(1, 8)

    for invader in invaders:
        invader.move_invader(num_movements)

    for invader in invaders:
        if invader.rect.centerx >= screen_width - 30:
            invader_left_movement = True
            invader_right_movement = False
        if invader.rect.centerx <= 0 + 30:
            invader_left_movement = False
            invader_right_movement = True


    FPSCLOCK = pygame.time.Clock()

    #movement of bullet

    for bullet in range(len(bullets_fired)-1,-1,-1): 
        for invader in invaders:
            if invader.rect.colliderect(bullets_fired[bullet]):
                score += 1
                invader_x = DISPLAYSURF_rect.centerx
                invader_x = DISPLAYSURF_rect.top + 40
                del bullets_fired[bullet]
                bullet_fired = False
            elif bullets_fired[bullet].y > 0:
                bullet_fired = True
                bullets_fired[bullet].y -=  14
                pygame.draw.rect(DISPLAYSURF,RED,bullets_fired[bullet])


    for event in pygame.event.get():
        if event.type == QUIT:
            pygame.quit()
            sys.exit()

        elif event.type == KEYDOWN:
            #Movement of player
            if event.key == K_RIGHT:
                move_right = True
            elif event.key == K_LEFT:
                move_left = True

            #Bullet firing
            elif event.key == K_SPACE:
                if bullet_fired == False:
                    rect = spaceship_rect
                    rect.x = spaceship_rect.centerx - 3
                    rect.y = spaceship_rect.top
                    bullets_fired.append(rect)

        elif event.type == KEYUP:
            #Movement of player
            if event.key == K_RIGHT:
                move_right = False
            elif event.key == K_LEFT:
                move_left = False

    text = FONT.render('Score ' + str(score), True, (180, 180, 180))

    if move_right == True and spaceship_rect.right <= screen_width:
        spaceship_rect.centerx += move_rate
    if move_left == True and spaceship_rect.left >= 0:
        spaceship_rect.centerx -= move_rate

    pygame.display.update()
    FPSCLOCK.tick(FPS)

Answer 1

問題是您在每一幀都調用 class ，這會將其值放回__init__中分配的值。 您應該在開始時調用 class 一次，然后每幀調用這些方法。 這是一個鏈接以了解有關課程的更多信息。

要修復您的代碼，請執行以下操作：

while True:

    #do other stuff

    for invader in invaders:
        invader.move_invader()

    #do other stuff

由於所有入侵者都有相同的形象，你可以

invader_image = pygame.image.load('invader.bmp')
invaders = []
for x in invader_x:
    invaders.append(Invader(invader_image,x,40,1))

這應該將每個入侵者每幀移動 1 個像素

---

要獲得碰撞的矩形，您可以將矩形添加到 class

class Invader
    def __init__(self, invader, invader_x, invader_y, movement):
        self.rect = invader.get_rect()
        self.rect.x = invader_x
        self.rect.y = invader_y
        #rest of code

    def move_invader(self):
        #if moveing move x
        self.rect.x = x
        #rest of code

和碰撞

for bullet in range(len(bullets_fired)-1,-1,-1): 
    for invader in invaders:
        if invader.rect.colliderect(bullets_fired[bullet]):
            score += 1
            invader_x = DISPLAYSURF_rect.centerx
            invader_x = DISPLAYSURF_rect.top + 40
            del bullets_fired[bullet]
            invaders.remove(invader) #to get rid of the invader too
            bullet_fired = False
            break
       elif bullets_fired[bullet].y > 0:
            bullet_fired = True
            bullets_fired[bullet].y -=  14
            bullet_rect = pygame.draw.rect(DISPLAYSURF, RED, (x, y, width, height))

對於碰撞，我向后循環，因為如果您刪除列表中的第 2 個項目符號，則第 3 個成為第 2 個，並且循環轉到第 3 個（即第 4 個）跳過一個項目符號。 但是如果你向后 go，如果你刪除一個子彈，你已經檢查過的子彈會被移動，你可以繼續檢查下一個。

---

對於子彈，您有 bullet 和 bullet_rect 是相同的東西，並且您有一個子彈列表，就個人而言，我會擺脫 bullet_rect

bullet = pygame.draw.rect(screen,RED,(x,y,w,y))

為了

pygame.draw.rect(screen,RED,bullets_fired[bullet]

現在在你添加項目符號的地方，當你按空格鍵時，而不是得到 y，只得到 rect

elif event.key == K_SPACE:
    if bullet_fired == False:
        rect = spaceship_rect.copy() # this makes the bullet the same size as the ship
        #you could also do rect = pygame.rect(0,0,0,0)
        rect.x = spaceship_rect.centerx - 3
        rect.y = spaceship_rect.top
        #rect.w = width
        #rect.h = height
        bullets_fired.append(rect)

回到碰撞循環中，將 y 更改為 bullets_fired[bullet].y