如何在pygame中创建项目符号？

Question

我知道有几个主题,但我仍然无法弄清楚如何让我的船射击子弹..我想添加我的MOUSEBUTTONDOWN子弹从船上拍摄,因为声音效果播放.谢谢您的帮助!

import sys, pygame, pygame.mixer
from pygame.locals import *

pygame.init()

size = width, height = 800, 600
screen = pygame.display.set_mode(size)

clock = pygame.time.Clock()

background = pygame.image.load("bg.png")
ship = pygame.image.load("ship.png")
ship = pygame.transform.scale(ship,(64,64))

shot = pygame.mixer.Sound("shot.wav")
soundin = pygame.mixer.Sound("sound.wav")

soundin.play()

while 1:
  for event in pygame.event.get():
    if event.type == pygame.QUIT:
      sys.exit()

    elif event.type == MOUSEBUTTONDOWN:
      shot.play()

  clock.tick(60)

  mx,my = pygame.mouse.get_pos()

  screen.blit(background,(0,0))
  screen.blit(ship,(mx-32,500))
  pygame.display.flip()

Answer 1

要完成此操作,您需要执行几个步骤.您将需要一张子弹的图片,一种存储子弹位置的方法,一种制作子弹的方法,一种渲染子弹的方法以及一种更新子弹的方法.您似乎已经知道如何导入图片,所以我将跳过该部分.

您可以通过多种方式存储信息.我将使用子弹左上角的列表.在最终循环之前的任何位置创建列表bullets = [].

要创建项目符号,您需要使用鼠标的位置.在添加bullets.append([event.pos[0]-32, 500])后shot.play(),同样缩进.

要渲染项目符号,您将在游戏循环中添加for循环.在该行之后screen.blit(background, (0, 0)),添加以下代码:

for bullet in bullets:
    screen.blit(bulletpicture, pygame.Rect(bullet[0], bullet[1], 0, 0)

要更新项目符号,您需要在游戏循环中放置一些如下所示的内容:

for b in range(len(bullets)):
    bullets[b][0] -= 10

最后,您需要在子弹到达屏幕顶部时将其删除.在刚刚创建的for循环之后添加它(迭代切片副本,因为在迭代期间不应修改列表):

for bullet in bullets[:]:
    if bullet[0] < 0:
        bullets.remove(bullet)

将此全部放入您的代码后,它应该看起来像这样:

import sys, pygame, pygame.mixer
from pygame.locals import *

pygame.init()

size = width, height = 800, 600
screen = pygame.display.set_mode(size)

clock = pygame.time.Clock()

bullets = []

background = pygame.image.load("bg.png").convert()
ship = pygame.image.load("ship.png").convert_alpha()
ship = pygame.transform.scale(ship, (64, 64))
bulletpicture = pygame.image.load("You know what to do").convert_alpha()

shot = pygame.mixer.Sound("shot.wav")
soundin = pygame.mixer.Sound("sound.wav")

soundin.play()

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

        elif event.type == MOUSEBUTTONDOWN:
            shot.play()
            bullets.append([event.pos[0]-32, 500])

    clock.tick(60)

    mx, my = pygame.mouse.get_pos()

    for b in range(len(bullets)):
        bullets[b][0] -= 10

    # Iterate over a slice copy if you want to mutate a list.
    for bullet in bullets[:]:
        if bullet[0] < 0:
            bullets.remove(bullet)

    screen.blit(background, (0, 0))

    for bullet in bullets:
        screen.blit(bulletpicture, pygame.Rect(bullet[0], bullet[1], 0, 0))

    screen.blit(ship, (mx-32, 500))
    pygame.display.flip()

如果你和我都正确地完成了所有事情,这应该会给你带来有效的子弹.如果你不明白发生了什么或者什么不起作用,请不要犹豫,问我任何问题.

请注意,应使用convert或convert_alpha方法转换images/pygame.Surfaces 以提高性能.

Answer 2

下面的示例演示了如何使用pygame.sprite.Sprites 和s 创建项目符号。pygame.sprite.Group它还展示了如何借助计时器变量和返回的dt（增量时间）连续拍摄clock.tick。

pygame.sprite.groupcollide用于子弹与enemies精灵组之间的碰撞检测。我迭代字典中的项目hits以减少敌人的生命值。

import random
import pygame as pg


pg.init()

BG_COLOR = pg.Color('gray12')
PLAYER_IMG = pg.Surface((30, 50), pg.SRCALPHA)
pg.draw.polygon(PLAYER_IMG, pg.Color('dodgerblue'), [(0, 50), (15, 0), (30, 50)])
ENEMY_IMG = pg.Surface((50, 30))
ENEMY_IMG.fill(pg.Color('darkorange1'))
BULLET_IMG = pg.Surface((9, 15))
BULLET_IMG.fill(pg.Color('aquamarine2'))


class Player(pg.sprite.Sprite):

    def __init__(self, pos, all_sprites, bullets):
        super().__init__()
        self.image = PLAYER_IMG
        self.rect = self.image.get_rect(center=pos)
        self.all_sprites = all_sprites
        self.add(self.all_sprites)
        self.bullets = bullets
        self.bullet_timer = .1

    def update(self, dt):
        self.rect.center = pg.mouse.get_pos()

        mouse_pressed = pg.mouse.get_pressed()
        self.bullet_timer -= dt  # Subtract the time since the last tick.
        if self.bullet_timer <= 0:
            self.bullet_timer = 0  # Bullet ready.
            if mouse_pressed[0]:  # Left mouse button.
                # Create a new bullet instance and add it to the groups.
                Bullet(pg.mouse.get_pos(), self.all_sprites, self.bullets)
                self.bullet_timer = .1  # Reset the timer.


class Enemy(pg.sprite.Sprite):

    def __init__(self, pos, *sprite_groups):
        super().__init__(*sprite_groups)
        self.image = ENEMY_IMG
        self.rect = self.image.get_rect(center=pos)
        self.health = 30

    def update(self, dt):
        if self.health <= 0:
            self.kill()


class Bullet(pg.sprite.Sprite):

    def __init__(self, pos, *sprite_groups):
        super().__init__(*sprite_groups)
        self.image = BULLET_IMG
        self.rect = self.image.get_rect(center=pos)
        self.pos = pg.math.Vector2(pos)
        self.vel = pg.math.Vector2(0, -450)
        self.damage = 10

    def update(self, dt):
        # Add the velocity to the position vector to move the sprite.
        self.pos += self.vel * dt
        self.rect.center = self.pos  # Update the rect pos.
        if self.rect.bottom <= 0:
            self.kill()


class Game:

    def __init__(self):
        self.clock = pg.time.Clock()
        self.screen = pg.display.set_mode((800, 600))

        self.all_sprites = pg.sprite.Group()
        self.enemies = pg.sprite.Group()
        self.bullets = pg.sprite.Group()
        self.player = Player((0, 0), self.all_sprites, self.bullets)

        for i in range(15):
            pos = (random.randrange(30, 750), random.randrange(500))
            Enemy(pos, self.all_sprites, self.enemies)

        self.done = False

    def run(self):
        while not self.done:
            # dt = time since last tick in milliseconds.
            dt = self.clock.tick(60) / 1000
            self.handle_events()
            self.run_logic(dt)
            self.draw()

    def handle_events(self):
        for event in pg.event.get():
            if event.type == pg.QUIT:
                self.done = True

    def run_logic(self, dt):
        self.all_sprites.update(dt)

        # hits is a dict. The enemies are the keys and bullets the values.
        hits = pg.sprite.groupcollide(self.enemies, self.bullets, False, True)
        for enemy, bullet_list in hits.items():
            for bullet in bullet_list:
                enemy.health -= bullet.damage

    def draw(self):
        self.screen.fill(BG_COLOR)
        self.all_sprites.draw(self.screen)
        pg.display.flip()


if __name__ == '__main__':
    Game().run()
    pg.quit()